Bitmasks - SDSS

SDSS makes heavy use of the concept of a bitmask in spectroscopic target flags and other contexts. For the actual bit values for all SDSS flags, see the lists below. More detailed descriptions of the targeting bitmasks for the completed optical surveys and infrared surveys can be found in the DR17 release documentation.

The page using bitmasks provides help in using these bitmask with IDL, python, and CAS.

SDSS-V Bitmasks

BOSS Spectroscopic

SPPIXMASK
ZWARNING
ZWARNING_NOQSO

SDSSV_BOSS_TARGET0

Bit Name	Bit Number	Decimal Value	Description
SKY	0	1	empty sky fiber for calibrating night sky emission
OPS_STD_EBOSS	1	2	spectrophotometric flux standard from eBOSS survey. Includes BOSS F dwarf flux standard selected at narrower magnitude range and wider color range, QSOs, and White Dwarfs
OPS_STD_BOSS	2	4	spectrophotometric flux standard selected via Gaia color-mag cuts designed to emulate prior SDSS-photometry based selection of F dwarf flux standards
OPS_STD_BOSS-RED	3	8	spectrophotometric flux standard selected via de-reddened Gaia-2MASS color/mag/reduced proper motion cuts (designed to provide F star flux standards even in highly reddened regions)
OPS_STD_BOSS_TIC	4	16	spectrophotometric flux standard F-dwarf targets selected from the TIC catalogue, based on Teff and logg, plus GAIA magnitudes
OPS_SKY_BOSS-NOTDB	5	32	empty sky fiber chosen by platedesign pipeline
OPS_SKY_2MASS	6	64	empty sky fiber obtained with SDSS-IV Apogee method
SPARE	7	128
BHM_RM_CORE	8	256	Selected as a target of Black Hole Mapper’s (BHM) Reverberation Mapping (RM) sample – targets selected by a QSO classification and photoz regression algorithm based on multi-dimensional Skew-t functions.
BHM_RM_KNOWN-SPEC	9	512	Selected as a target of Black Hole Mapper’s (BHM) Reverberation Mapping (RM) sample – targets selected because they have existing spectroscopic confirmations
BHM_RM_VAR	10	1024	Selected as a target of Black Hole Mapper’s (BHM) Reverberation Mapping (RM) sample – targets selected by optical variability (DES, PS1) properties
BHM_RM_ANCILLARY	11	2048	Selected as a target of Black Hole Mapper’s (BHM) Reverberation Mapping (RM) sample – targets selected by WISE colours or by the XDQSO algorithm
SPARE	12	4096
SPARE	13	8192
BHM_AQMES_MED	14	16384	Selected as a target of BHM’s Apache Point Observatory Quasar Multi-Epoch Survey (AQMES) Medium cadence sample
BHM_AQMES_MED-FAINT	15	32768	Selected as a target of BHM’s AQMES Medium cadence faint object sample
BHM_AQMES_WIDE3	16	65536	Selected as a target of BHM’s AQMES wide 3-epoch cadence sample
BHM_AQMES_WIDE3-FAINT	17	131072	Selected as a target of BHM’s AQMES wide 3-epoch cadence faint object sample
BHM_AQMES_WIDE2	18	262144	Selected as a target of BHM’s AQMES wide 2-epoch cadence sample
BHM_AQMES_WIDE2-FAINT	19	524288	Selected as a target of BHM’s AQMES wide 2-epoch cadence faint object sample
BHM_AQMES_BONUS-DARK	20	1048576	Selected as a target of BHM’s AQMES bonus dark-time sample
BHM_AQMES_BONUS-BRIGHT	21	2097152	Selected as a target of BHM’s AQMES bonus bright-time sample
SPARE	22	4194304
SPARE	23	8388608
BHM_SPIDERS_CLUSTERS-EFEDS-SDSS-REDMAPPER	24	16777216	Selected as a target of BHM’s SPIDERS clusters eFEDS RedMapper sample using SDSS photometry
BHM_SPIDERS_CLUSTERS-EFEDS-HSC-REDMAPPER	25	33554432	Selected as a target of BHM’s SPIDERS clusters eFEDS RedMapper sample using HyperSuprimeCam photometry
BHM_SPIDERS_CLUSTERS-EFEDS-LS-REDMAPPER	26	67108864	Selected as a target of BHM’s SPIDERS clusters eFEDS RedMapper sample using LegacySurvey photometry
BHM_SPIDERS_CLUSTERS-EFEDS-EROSITA	27	134217728	Selected as a target of BHM’s SPIDERS clusters eFEDS eROSITA sample
BHM_SPIDERS_AGN-EFEDS	28	268435456	Selected as a target of BHM’s SPIDERS AGN eFEDS sample
SPARE	29	536870912
SPARE	30	1073741824
BHM_CSC_BOSS-DARK	31	2147483648	Selected as a target of BHM’s Chandra Source Catalog (CSC) dark-time sample
BHM_CSC_BOSS-BRIGHT	32	4294967296	Selected as a target of BHM’s Chandra Source Catalog (CSC) bright-time sample
BHM_GUA_DARK	33	8589934592	Selected as a target of BHM’s Gaia/UnWISE AGN dark-time sample
BHM_GUA_BRIGHT	34	17179869184	Selected as a target of BHM’s Gaia/UnWISE AGN brght-time sample
SPARE	35	34359738368
SPARE	36	68719476736
MWM_SNC_100PC	37	137438953472	Selected as a target of the MWM’s Solar Neighborhood Census (SNC) 100pc sample
MWM_CB_300PC	38	274877906944	Selected as a target of the MWM’s Compact Binary (CB) 300pc sample
MWM_CB_CVCANDIDATES	39	549755813888	Selected as a target of the MWM’s CB Cataclysmic Variable candidate sample
MWM_CB_GAIAGALEX	40	1099511627776	Selected as a target of the MWM’s CB Gaia-Galex sample
MWM_CB_UVEX1	41	2199023255552	Selected as a target of the MWM’s CB UV-selected sample
MWM_WD	42	4398046511104	Selected as a target of the MWM’s White Dwarf sample
MWM_SNC_250PC	43	8796093022208	Selected as a target of the MWM’s SNC 250pc sample
MWM_CV_FAINT	44	17592186044416	Selected as a target of the MWM’s faint Cataclysmic variable (CV) sample
MWM_CV_GREY	45	35184372088832	Selected as a target of the MWM’s grey-time Cataclysmic variable (CV) sample
MWM_CV_BRIGHT	46	70368744177664	Selected as a target of the MWM’s bright CV sample
MWM_HALO_BB	47	140737488355328	Selected as a target of the MWM’s Halo Star Best & Brightest sample
MWM_HALO_SM	48	281474976710656	Selected as a target of the MWM’s Halo Star SM sample
MWM_YSO_S1	49	562949953421312	Selected as a target of the MWM’s YSO Optically visible Class I/II sample
MWM_YSO_S3	50	1125899906842620	Selected as a target of the MWM’s YSO Optically variable Class III sample
MWM_YSO_CLUSTER	51	2251799813685250	Selected as a target of the MWM’s YSO Clustering selected sample
MWM_OB	52	4503599627370500	Selected as a target of the MWM’s OB star sample
MWM_OB_CEPHEIDS	53	9007199254740990	Selected as a target of the MWM’s OB Cepheid star sample
MWM_LEGACY_IR2OPT	54	18014398509482000	Selected as a target of the MWM’s APOGEE legacy observations
MWM_CB_UVEX2	55	36028797018964000	Selected as a target of the MWM’s CB UV-selected sample
MWM_CB_UVEX3	56	72057594037927900	Selected as a target of the MWM’s CB UV-selected sample
MWM_CB_UVEX4	57	144115188075856000	Selected as a target of the MWM’s CB UV-selected sample
MWM_CB_UVEX5	58	288230376151712000	Selected as a target of the MWM’s CB UV-selected sample
SPARE	59	576460752303423000
SPARE	60	1152921504606850000
SPARE	61	2305843009213690000
SPARE	62	4611686018427390000

These are the targeting flag bit masks utilized for the SDSS-V BOSS Plate Program.

SDSSV_APOGEE_TARGET0

These are the targeting flag bit masks utilized for the SDSS-V APOGEE Plate Program.

Bit Name	Bit Number	Decimal Value	Description
SKY	0	1	empty sky fiber for calibrating night sky emission
OPS_APOGEE_STD	1	2	telluric/flux standard
OPS_SKY_2MASS	2	4	empty sky fiber obtained with SDSS-IV Apogee method
OPS_STD_2MASS	3	8	telluric/flux standard obtained with SDSS-IV Apogee method
spare	4	16
spare	5	32
spare	6	64
MWM_SNC_100PC	7	128	Selected as a target of the Milky Way Mapper’s (MWM) Solar Neighborhood Census (SNC) 100pc sample
MWM_SNC_250PC	8	256	Selected as a target of the MWM’s SNC 250pc sample
MWM_RV_LONG-BPLATES	9	512	Selected as a target of the MWM’s Radial Velocity (RV) Long Cadence Plate Program Sample
MWM_RV_SHORT-BPLATES	10	1024	Selected as a target of the MWM’s RV Short Cadence Plate Program Sample
MWM_RV_LONG-RM	11	2048	Selected as a target of the MWM’s RV Reverberation Mapping (RM) Long Cadence Co-observing sample
MWM_RV_SHORT-RM	12	4096	Selected as a target of the MWM’s RV RM Short Cadence Co-observing sample
MWM_PLANET_TESS	13	8192	Selected as a target of the MWM’s TESS planet host characterization sample
MWM_YSO_CMZ	14	16384	Selected as a target of the MWM’s Young Stellar Object (YSO) Central Molecular Zone (CMZ) sample
MWM_YSO_OB	15	32768	Selected as a target of the MWM’s YSO OB star sample
MWM_YSO_S1	16	65536	Selected as a target of the MWM’s YSO Optically visible Class I/II sample
MWM_YSO_S2	17	131072	Selected as a target of the MWM’s YSO Optically invisible Class I/II sample
MWM_YSO_S2-5	18	262144	Selected as a target of the MWM’s YSO WISE saturated sample
MWM_YOS_S3	19	524288	Selected as a target of the MWM’s YSO Optically variable Class III sample
MWM_YSO_CLUSTER	20	1048576	Selected as a target of the MWM’s YSO Clustering selected sample
MWM_GG	21	2097152	Selected as a target of the MWM’s Galactic Genesis sample
MWM_DUST	22	4194304	Selected as a target of the MWM’s Dust sample
MWM_TESSRGB	23	8388608	Selected as a target of the MWM’s TESS Red Giant Branch (RGB) sample
BHM_CSC_APOGEE	24	16777216	Selected as a target of the Black Hole Mapper’s (BHM) Chandra Source Catalog (CSC) APOGEE follow-up sample
MWM_RV_long-FPS	25	33554432	Selected as a target of the MWM’s Radial Velocity Long Cadence FPS Program
MWM_RV_SHORT-FPS	26	67108864	Selected as a target of the MWM’s Radial Velocity Short Cadence FPS Program
SPARE	27	134217728
SPARE	28	268435456
SPARE	29	536870912
SPARE	30	1073741824
CHECKED?	31	2147483648	bit 31 is apparently always set to indicate that the target selection has been checked.

GRI_GAIA_TRANSFORM

This flag helps track the provenance of ugriz photometry that is supplied in the SDSS-V plate design process

Bit Name	Bit Number	Decimal Value	Description
U_GAIA_TRANSFORMED	0	1	u photometry provided for plate design is transformed from Gaia mags.
U_GAIA_OUTSIDE	1	2	u photometry cannot be calculated from Gaia photometry as it lies outside range of colors for which transforms are defined
U_GAIA_NONE	2	4	u photometry cannot be calculated for this source
G_GAIA_TRANSFORMED	3	8	g photometry provided for plate design is transformed from Gaia mags.
G_GAIA_OUTSIDE	4	16	g photometry cannot be calculated from Gaia photometry as it lies outside range of colors for which transforms are defined
G_GAIA_NONE	5	32	g photometry cannot be calculated for this source
R_GAIA_TRANSFORMED	6	64	r photometry provided for plate design is transformed from Gaia mags.
R_GAIA_OUTSIDE	7	128	r photometry cannot be calculated from Gaia photometry as it lies outside range of colors for which transforms are defined
R_GAIA_NONE	8	256	r photometry cannot be calculated for this source
I_GAIA_TRANSFORMED	9	512	i photometry provided for plate design is transformed from Gaia mags.
I_GAIA_OUTSIDE	10	1024	i photometry cannot be calculated from Gaia photometry as it lies outside range of colors for which transforms are defined
I_GAIA_NONE	11	2048	i photometry cannot be calculated for this source
Z_GAIA_TRANSFORMED	12	4096	z photometry provided for plate design is transformed from Gaia mags.
Z_GAIA_OUTSIDE	13	8192	z photometry cannot be calculated from Gaia photometry as it lies outside range of colors for which transforms are defined
Z_GAIA_NONE	14	16384	z photometry cannot be calculated for this source
GAIA_NEIGHBOR	15	32768	bright gaia neighbor close to the star
G_PANSTARRS	16	65536	g photometry provided by PanSTARRS
R_PANSTARRS	17	131072	r photometry provided by PanSTARRS
I_PANSTARRS	18	262144	i photometry provided by PanSTARRS
Z_PANSTARRS	19	524288	z photometry provided by PanSTARRS
OFFSET	20	1048576	position shifted with respect to center of star (catalogid corresponds to GAIA id)

SPPIXMASK: Mask bits for an SDSS spectrum

Each of these bits is set for each fiber and each pixel. Bits 0-15 indicate something about the spectrum as a whole, or at least about its red or blue half (corresponding to the two spectrographs). Within a spectrum, if these bits are set they will be set for all the bits in one or both of the halves. Bits 16-31 indicate something about each particular pixel.
The conditions that are considered very bad are already used to set the errors to infinity for the effected pixels (specifically, the inverse variance is set to zero). The most useful mask bit to look at is BRIGHTSKY, which indicates when the sky is so bright relative to the object that perhaps one shouldn’t trust any of the object flux there. Our reported errors are meant to include sky-subtraction errors, but there are instances (particularly around 5577) where these errors may be untrustworthy.

Bit Name	Binary Digit	Description
NOPLUG	0	Fiber not listed in plugmap file
BADTRACE	1	Bad trace from routine TRACE320CRUDE
BADFLAT	2	Low counts in fiberflat
BADARC	3	Bad arc solution
MANYBADCOLUMNS	4	More than 10% of pixels are bad columns
MANYREJECTED	5	More than 10% of pixels are rejected in extraction
LARGESHIFT	6	Large spatial shift between flat and object position
BADSKYFIBER	7	Sky fiber shows extreme residuals
NEARWHOPPER	8	DEPRECATED, no longer set as of BOSS DR9. Prior to DR9 meant within 2 fibers of a whopping fiber (exclusive)
WHOPPER	9	Whopping fiber, with a very bright source.
SMEARIMAGE	10	DEPRECATED. Prior to DR9 meant smear available for red and blue cameras
SMEARHIGHSN	11	DEPRECATED. Prior to DR9 meant S/N sufficient for full smear fit
SMEARMEDSN	12	DEPRECATED. Prior to DR9 meant S/N only sufficient for scaled median fit
NEARBADPIXEL	16	Bad pixel within 3 pixels of trace.
LOWFLAT	17	Flat field less than 0.5
FULLREJECT	18	Pixel fully rejected in extraction (INVVAR=0)
PARTIALREJECT	19	Some pixels rejected in extraction
SCATTEREDLIGHT	20	Scattered light significant
CROSSTALK	21	Cross-talk significant
NOSKY	22	Sky level unknown at this wavelength (INVVAR=0)
BRIGHTSKY	23	Sky level > flux + 10(flux_err) AND sky > 1.25 median(sky,99 pixels)
NODATA	24	DEPRECATED, should be ignored in favor of flagging on INVVAR=0. Prior to DR9 meant no data available in combine B-spline (INVVAR=0)
COMBINEREJ	25	Rejected in combine B-spline
BADFLUXFACTOR	26	Low flux-calibration or flux-correction factor
BADSKYCHI	27	Relative ?² > 3 in sky residuals at this wavelength
REDMONSTER	28	Contiguous region of bad ?² in sky residuals (with threshold of relative ?² > 3).

ZWARNING: Warnings for SDSS spectra

Spectra with zWarning equal to zero have no known problems. MANY_OUTLIERS is only ever set in the data taken with the SDSS spectrograph, not the BOSS spectrograph (the SDSS-I, -II and SEGUE-2 surveys). If it is set, that usually indicates a high signal-to-noise spectrum or broad emission lines in a galaxy; that is, MANY_OUTLIERS only rarely signifies a real error.

Bit Name	Binary Digit	Description
SKY	0	sky fiber
LITTLE_COVERAGE	1	too little wavelength coverage (WCOVERAGE < 0.18)
SMALL_DELTA_CHI2	2	chi-squared of best fit is too close to that of second best (< 0.01 in reduced chi-squared)
NEGATIVE_MODEL	3	synthetic spectrum is negative (only set for stars and QSOs)
MANY_OUTLIERS	4	fraction of points more than 5 sigma away from best model is too large (> 0.05)
Z_FITLIMIT	5	chi-squared minimum at edge of the redshift fitting range (Z_ERR set to -1)
NEGATIVE_EMISSION	6	a QSO line exhibits negative emission, triggered only in QSO spectra, if C_IV, C_III, Mg_II, H_beta, or H_alpha has LINEAREA + 3 * LINEAREA_ERR < 0
UNPLUGGED	7	the fiber was unplugged or damaged, and the location of any spectrum is unknown
BAD_TARGET	8	catastrophically bad targeting data (e.g. bad astrometry)
NODATA	9	No data for this fiber, e.g. because spectrograph was broken during this exposure (ivar=0 for all pixels)

ZWARNING_NOQSO: Warnings for SDSS/BOSS spectra

Same as ZWARNING above but without taking into account QSO templates when determining the best fit template model to the spectra. It only compares GALAXY and STAR templates. It is the target bit used to select confident galaxy redshifts in BOSS and eBOSS.

Completed Survey Bitmasks

FLAGS1: Object flags from photo reductions (first 32 of CAS flags bitmask)

In the flat-files, the photo flags are split into two 32-bit variables (objc_flags1 and objc_flags2). In the CAS, these are combined into a single variable flags. The flags listed here are associated with objc_flags1, and the first 32-bits of flags. Note there are also flags on a per-band basis. The names of these flags in the CAS are appended with the band, e.g. flags_r. In the flat files an array of length 5 is used flags[5] ordered u,g,r,i,z

Bit name	Binary digit	Description
CANONICAL_CENTER	0	The quantities (psf counts, model fits and likelihoods) that are usually determined at an object’s center as determined band-by-band were in fact determined at the canonical center (suitably transformed). This is due to the object being to close to the edge to extract a profile at the local center, and OBJECT1_EDGE is also set.
BRIGHT	1	Indicates that the object was detected as a bright object. Since these are typically remeasured as faint objects, most users can ignore BRIGHT objects.
EDGE	2	Object is too close to edge of frame in this band.
BLENDED	3	Object was determined to be a blend. The flag is set if: more than one peak is detected within an object in a single band together; distinct peaks are found when merging different colors of one object together; or distinct peaks result when merging different objects together.
CHILD	4	Object is a child, created by the deblender.
PEAKCENTER	5	Given center is position of peak pixel, as attempts to determine a better centroid failed.
NODEBLEND	6	Although this object was marked as a blend, no deblending was attempted.
NOPROFILE	7	Frames couldn’t extract a radial profile.
NOPETRO	8	No Petrosian radius or other Petrosian quantities could be measured.
MANYPETRO	9	Object has more than one possible Petrosian radius.
NOPETRO_BIG	10	The Petrosian ratio has not fallen to the value at which the Petrosian radius is defined at the outermost point of the extracted radial profile. NOPETRO is set, and the Petrosian radius is set to the outermost point in the profile.
DEBLEND_TOO_MANY_PEAKS	11	The object had the OBJECT1_DEBLEND flag set, but it contained too many candidate children to be fully deblended. This flag is only set in the parent, i.e. the object with too many peaks.
CR	12	Object contains at least one pixel which was contaminated by a cosmic ray. The OBJECT1_INTERP flag is also set. This flag does not mean that this object is a cosmic ray; rather it means that a cosmic ray has been removed.
MANYR50	13	More than one radius was found to contain 50% of the Petrosian flux. (For this to happen part of the radial profile must be negative).
MANYR90	14	More than one radius was found to contain 90% of the Petrosian flux. (For this to happen part of the radial profile must be negative).
BAD_RADIAL	15	Measured profile includes points with a S/N <= 0. In practice this flag is essentially meaningless.
INCOMPLETE_PROFILE	16	A circle, centered on the object, of radius the canonical Petrosian radius extends beyond the edge of the frame. The radial profile is still measured from those parts of the object that do lie on the frame.
INTERP	17	The object contains interpolated pixels (e.g. cosmic rays or bad columns).
SATUR	18	The object contains saturated pixels; INTERP is also set.
NOTCHECKED	19	Object includes pixels that were not checked for peaks, for example the unsmoothed edges of frames, and the cores of subtracted or saturated stars.
SUBTRACTED	20	Object (presumably a star) had wings subtracted.
NOSTOKES	21	Object has no measured Stokes parameters.
BADSKY	22	The estimated sky level is so bad that the central value of the radial profile is crazily negative; this is usually the result of the subtraction of the wings of bright stars failing.
PETROFAINT	23	At least one candidate Petrosian radius occurred at an unacceptably low surface brightness.
TOO_LARGE	24	The object is (as it says) too large. Either the object is still detectable at the outermost point of the extracted radial profile (a radius of approximately 260 arcsec), or when attempting to deblend an object, at least one child is larger than half a frame (in either row or column).
DEBLENDED_AS_PSF	25	When deblending an object, in this band this child was treated as a PSF.
DEBLEND_PRUNED	26	When solving for the weights to be assigned to each child the deblender encountered a nearly singular matrix, and therefore deleted at least one of them.
ELLIPFAINT	27	No isophotal fits were performed.
BINNED1	28	The object was detected in an unbinned image.
BINNED2	29	The object was detected in a 2×2 binned image after all unbinned detections have been replaced by the background level.
BINNED4	30	The object was detected in a 4×4 binned image. The objects detected in the 2×2 binned image are not removed before doing this.
MOVED	31	The object appears to have moved during the exposure. Such objects are candidates to be deblended as moving objects.

FLAGS2: Object flags from photo reductions (second 32 of CAS flags bitmask)

In the flat-files, the photo flags are split into two 32-bit variables (objc_flags1 and objc_flags2). In the CAS, these are combined into a single variable flags. The flags listed here are associated with objc_flags2, and the second 32-bits of flags. Note there are also flags on a per-band basis. The names of these flags in the CAS are appended with the band, e.g., flags_r. In the flat files an array of length 5 is used flags2[5] ordered u,g,r,i,z.

Bit name	Bit number	Description
DEBLENDED_AS_MOVING	0	The object has the MOVED flag set, and was deblended on the assumption that it was moving.
NODEBLEND_MOVING	1	The object has the MOVED flag set, but was not deblended as a moving object.
TOO_FEW_DETECTIONS	2	The object has the MOVED flag set, but has too few detection to be deblended as moving.
BAD_MOVING_FIT	3	The fit to the object as a moving object is too bad to be believed.
STATIONARY	4	A moving objects velocity is consistent with zero
PEAKS_TOO_CLOSE	5	Peaks in object were too close (set only in parent objects).
BINNED_CENTER	6	When centroiding the object the object’s size is larger than the (PSF) filter used to smooth the image.
LOCAL_EDGE	7	The object’s center in some band was too close to the edge of the frame to extract a profile.
BAD_COUNTS_ERROR	8	An object containing interpolated pixels had too few good pixels to form a reliable estimate of its error
BAD_MOVING_FIT_CHILD	9	A putative moving child’s velocity fit was too poor, so it was discarded, and the parent was not deblended as moving
DEBLEND_UNASSIGNED_FLUX	10	After deblending, the fraction of flux assigned to none of the children was too large (this flux is then shared out as described elsewhere).
SATUR_CENTER	11	An object’s center is very close to at least one saturated pixel; the object may well be causing the saturation.
INTERP_CENTER	12	An object’s center is very close to at least one interpolated pixel.
DEBLENDED_AT_EDGE	13	An object so close to the edge of the frame that it would not ordinarily be deblended has been deblended anyway. Only set for objects large enough to be EDGE in all fields/strips.
DEBLEND_NOPEAK	14	A child had no detected peak in a given band, but we centroided it anyway and set the BINNED1
PSF_FLUX_INTERP	15	The fraction of light actually detected (as opposed to guessed at by the interpolator) was less than some number (currently 80%) of the total.
TOO_FEW_GOOD_DETECTIONS	16	A child of this object had too few good detections to be deblended as moving.
CENTER_OFF_AIMAGE	17	At least one peak’s center lay off the atlas image in some band. This can happen when the object’s being deblended as moving, or if the astrometry is badly confused.
DEBLEND_DEGENERATE	18	At least one potential child has been pruned because its template was too similar to some other child’s template.
BRIGHTEST_GALAXY_CHILD	19	This is the brightest child galaxy in a blend.
CANONICAL_BAND	20	This band was the canonical band. This is the band used to measure the Petrosian radius used to calculate the Petrosian counts in each band, and to define the model used to calculate model colors; it has no effect upon the coordinate system used for the OBJC center.
AMOMENT_UNWEIGHTED	21	‘Adaptive’ moments are actually unweighted.
AMOMENT_SHIFT	22	Object’s center moved too far while determining adaptive moments. In this case, the M_e1 and M_e2 give the (row, column) shift, not the object’s shape.
AMOMENT_MAXITER	23	Too many iterations while determining adaptive moments.
MAYBE_CR	24	This object may be a cosmic ray. This bit can get set in the cores of bright stars, and is quite likely to be set for the cores of saturated stars.
MAYBE_EGHOST	25	Object appears in the right place to be an electronics ghost.
NOTCHECKED_CENTER	26	Center of object lies in a NOTCHECKED region. The object is almost certainly bogus.
HAS_SATUR_DN	27	This object is saturated in this band and the bleed trail doesn’t touch the edge of the frame, we we’ve made an attempt to add up all the flux in the bleed trails, and to include it in the object’s photometry.
DEBLEND_PEEPHOLE	28	The deblend was modified by the optimizer
SPARE3	29
SPARE2	30
SPARE1	31

RESOLVE_STATUS: Flags set by the resolve algorithm

Resolve status for an SDSS catalog entry. Only one of bits RUN_PRIMARY, RUN_RAMP, RUN_OVERLAPONLY, RUN_IGNORE, and RUN_DUPLICATE can be set. RUN_EDGE can be set for any object. To get a unique set of objects across the whole survey, search for objects with SURVEY_PRIMARY set. To get a unique set of objects within a run, search for objects with RUN_PRIMARY set.

Bit Name	Binary Digit	Description
RUN_PRIMARY	0	primary within the objects own run (but not necessarily for the survey as a whole)
RUN_RAMP	1	in what would be the overlap area of a field, but with no neighboring field
RUN_OVERLAPONLY	2	only appears in the overlap between two fields
RUN_IGNORE	3	bright or parent object that should be ignored
RUN_EDGE	4	near lowest or highest column
RUN_DUPLICATE	5	duplicate measurement of same pixels in two different fields
SURVEY_PRIMARY	8	Primary observation within the full survey, where it appears in the primary observation of this part of the sky
SURVEY_BEST	9	Best observation within the full survey, but it does not appear in the primary observation of this part of the sky
SURVEY_SECONDARY	10	Repeat (independent) observation of an object that has a different primary or best observation
SURVEY_BADFIELD	11	In field with score=0
SURVEY_EDGE	12	Not kept as secondary because it is RUN_RAMP or RUN_EDGE object

CALIB_STATUS: Calibration status for an SDSS image

In the flat files there are arrays of length five for each band calib_status[5] ordered u,g,r,i,z. In the CAS these are named by band pass calibstatus_{band}.

Bit Name	Binary Digit	Description
PHOTOMETRIC	0	Photometric observations
UNPHOT_OVERLAP	1	Unphotometric observations, calibrated based on overlaps with clear, ubercalibrated data; done on a field-by-field basis. Use with caution.
UNPHOT_EXTRAP_CLEAR	2	Extrapolate the solution from the clear part of a night (that was ubercalibrated) to the cloudy part. Not recommended for use.
UNPHOT_EXTRAP_CLOUDY	3	Extrapolate the solution from a cloudy part of the night (where there is overlap) to a region of no overlap. Not recommended for use.
UNPHOT_DISJOINT	4	Data is disjoint from the rest of the survey (even though conditions may be photometric), the calibration is suspect. Not recommended for use.
INCREMENT_CALIB	5	Incrementally calibrated by considering overlaps with ubercalibrated data
PS1_UNPHOT	6	PS1 comparison reveals unphotometric conditions
PS1_CONTRAIL	7	PS1 comparison shows slightly unphotometric conditions
PT_CLEAR	8	(INTERNAL USE ONLY in DR8 and later) PT calibration for clear data
PT_CLOUDY	9	(INTERNAL USE ONLY in DR8 and later) PT calibration for cloudy data
DEFAULT	10	(INTERNAL USE ONLY in DR8 and later) a default calibration used
NO_UBERCAL	11	(INTERNAL USE ONLY in DR8 and later) not uber-calibrated
PS1_PCOMP_MODEL	13	PS1 Used PCA model for flats
PS1_LOW_RMS	14	PS1 comparison to SDSS has low noise

IMAGE_STATUS: Sky and instrument conditions of SDSS image

Bit Name	Binary Digit	Description
CLEAR	0	Clear skies
CLOUDY	1	Cloudy skies (unphotometric)
UNKNOWN	2	Sky conditions unknown (unphotometric)
BAD_ROTATOR	3	Rotator problems (set score=0)
BAD_ASTROM	4	Astrometry problems (set score=0)
BAD_FOCUS	5	Focus bad (set score=0)
SHUTTERS	6	Shutter out of place (set score=0)
FF_PETALS	7	Flat-field petals out of place (unphotometric)
DEAD_CCD	8	CCD bad (unphotometric)
NOISY_CCD	9	CCD noisy (unphotometric)

LEGACY_TARGET1: Primary target mask bits in SDSS-I, -II (for LEGACY_TARGET1 or PRIMTARGET).

Bit Name	Binary Digit	Description
QSO_HIZ	0	High-redshift (griz) QSO target
QSO_CAP	1	ugri-selected quasar at high Galactic latitude
QSO_SKIRT	2	ugri-selected quasar at low Galactic latitude
QSO_FIRST_CAP	3	FIRST source with stellar colors at high Galactic latitude
QSO_FIRST_SKIRT	4	FIRST source with stellar colors at low Galactic latitude
GALAXY_RED	5	Luminous Red Galaxy target (any criteria)
GALAXY	6	Main sample galaxy
GALAXY_BIG	7	Low-surface brightness main sample galaxy (mu50 > 23 in r-band)
GALAXY_BRIGHT_CORE	8	Galaxy targets who fail all the surface brightness selection limits but have r-band fiber magnitudes brighter than 19
ROSAT_A	9	ROSAT All-Sky Survey match, also a radio source
ROSAT_B	10	ROSAT All-Sky Survey match, have SDSS colors of AGNs or quasars
ROSAT_C	11	ROSAT All-Sky Survey match, fall in a broad intermediate category that includes stars that are bright, moderately blue, or both
ROSAT_D	12	ROSAT All-Sky Survey match, are otherwise bright enough for SDSS spectroscopy
STAR_BHB	13	blue horizontal-branch stars
STAR_CARBON	14	dwarf and giant carbon stars
STAR_BROWN_DWARF	15	brown dwarfs (note this sample is tiled)
STAR_SUB_DWARF	16	low-luminosity subdwarfs
STAR_CATY_VAR	17	cataclysmic variables
STAR_RED_DWARF	18	red dwarfs
STAR_WHITE_DWARF	19	hot white dwarfs
SERENDIP_BLUE	20	lying outside the stellar locus in color space
SERENDIP_FIRST	21	coincident with FIRST sources but fainter than the equivalent in quasar target selection (also includes non-PSF sources)
SERENDIP_RED	22	lying outside the stellar locus in color space
SERENDIP_DISTANT	23	lying outside the stellar locus in color space
SERENDIP_MANUAL	24	manual serendipity flag
QSO_MAG_OUTLIER	25	Stellar outlier; too faint or too bright to be targeted
GALAXY_RED_II	26	Luminous Red Galaxy target (Cut II criteria)
ROSAT_E	27	ROSAT All-Sky Survey match, but too faint or too bright for SDSS spectroscopy
STAR_PN	28	central stars of planetary nebulae
QSO_REJECT	29	Object in explicitly excluded region of color space, therefore not targeted at QSO
SOUTHERN_SURVEY	31	Set in primtarget if this is a special program target

LEGACY_TARGET2: Secondary target mask bits in SDSS-I, -II

Bit Name	Binary Digit	Description
QSO_HIZ	0	High-redshift (griz) QSO target
QSO_CAP	1	ugri-selected quasar at high Galactic latitude
QSO_SKIRT	2	ugri-selected quasar at low Galactic latitude
QSO_FIRST_CAP	3	FIRST source with stellar colors at high Galactic latitude
QSO_FIRST_SKIRT	4	FIRST source with stellar colors at low Galactic latitude
GALAXY_RED	5	Luminous Red Galaxy target (any criteria)
GALAXY	6	Main sample galaxy
GALAXY_BIG	7	Low-surface brightness main sample galaxy (mu50 > 23 in r-band)
GALAXY_BRIGHT_CORE	8	Galaxy targets who fail all the surface brightness selection limits but have r-band fiber magnitudes brighter than 19
ROSAT_A	9	ROSAT All-Sky Survey match, also a radio source
ROSAT_B	10	ROSAT All-Sky Survey match, have SDSS colors of AGNs or quasars
ROSAT_C	11	ROSAT All-Sky Survey match, fall in a broad intermediate category that includes stars that are bright, moderately blue, or both
ROSAT_D	12	ROSAT All-Sky Survey match, are otherwise bright enough for SDSS spectroscopy
STAR_BHB	13	blue horizontal-branch stars
STAR_CARBON	14	dwarf and giant carbon stars
STAR_BROWN_DWARF	15	brown dwarfs (note this sample is tiled)
STAR_SUB_DWARF	16	low-luminosity subdwarfs
STAR_CATY_VAR	17	cataclysmic variables
STAR_RED_DWARF	18	red dwarfs
STAR_WHITE_DWARF	19	hot white dwarfs
SERENDIP_BLUE	20	lying outside the stellar locus in color space
SERENDIP_FIRST	21	coincident with FIRST sources but fainter than the equivalent in quasar target selection (also includes non-PSF sources)
SERENDIP_RED	22	lying outside the stellar locus in color space
SERENDIP_DISTANT	23	lying outside the stellar locus in color space
SERENDIP_MANUAL	24	manual serendipity flag
QSO_MAG_OUTLIER	25	Stellar outlier; too faint or too bright to be targeted
GALAXY_RED_II	26	Luminous Red Galaxy target (Cut II criteria)
ROSAT_E	27	ROSAT All-Sky Survey match, but too faint or too bright for SDSS spectroscopy
STAR_PN	28	central stars of planetary nebulae
QSO_REJECT	29	Object in explicitly excluded region of color space, therefore not targeted at QSO
SOUTHERN_SURVEY	31	Set in primtarget if this is a special program target

SEGUE1_TARGET: SEGUE-1 primary target bits (Aliased to SEGUE1_TARGET1)

Bit Name	Binary Digit	Description
SEGUE1_FG	9	F and G stars, based on g-r color (0.2 < g-r < 0.48 and 14 < g < 20.2)
SEG1LOW_KG	10	low latitude selection of K-giant stars
SEG1LOW_TO	11	low latitude selection of bluetip stars
SEGUE1_MSWD	12	main-sequence, white dwarf pair
SEGUE1_BHB	13	blue horizontal branch star
SEGUE1_KG	14	K-giants (l and red)
SEGUE1_KD	15	K-dwarfs
SEGUE1_LM	16	low metallicity star
SEGUE1_CWD	17	cool white dwarf
SEGUE1_GD	18	G-dwarf
SEGUE1_WD	19	white dwarf
SEGUE1_MPMSTO	20	metal-poor main sequence turn-off
SEGUE1_BD	21	brown dwarfs
SEGUE1_SDM	22	M sub-dwarfs
SEGUE1_AGB	23	asymptotic giant branch stars
SEGUE1_MAN	24	manual selection
SEG1LOW_AGB	27	low latitude selection of AGB stars
SEGUE1_CHECKED	31	was a checked object

More detailed information about the selection criteria for SEGUE-1 is available on the archived SEGUE Target Selection page.

SEGUE1_TARGET2: SEGUE-1 secondary target bits

Bit Name	Binary Digit	Description
REDDEN_STD	1	reddening standard star
SEGUE1_QA ¹	3	QA Duplicate Observations (unused)
SKY	4	sky target
SPECTROPHOTO_STD	5	spectrophotometry standard (typically an F-star)
SEGUE1_SCIENCE ²	30	SEGUE-1 science target
SEGUE1_TEST ³	31	SEGUE-1 test target

Notes
¹ QA duplicate observations are not currently marked in SEGUE1_TARGET2 bitmasks.
² These are only marked in sourcetype in SpecObjAll.
³ These objects are specific science targets, but since reddening and spectrophotometric targets were also used for SEGUE science, it is not quite as useful as it might appear. Use with caution! These objects have programname ‘segtest’, but not all ‘segtest’ plates have this bit set. Use with caution!

SEGUE2_TARGET1: SEGUE-2 primary target bits

Bit Name	Binary Digit	Description
SEGUE2_MSTO	0	Main-sequence turnoff
SEGUE2_REDKG	1	Red K-giant stars
SEGUE2_LKG	2	K-giant star identified by l-color
SEGUE2_PMKG	3	K-giant star identified by proper motions
SEGUE2_LM	4	Low metallicity
SEGUE2_HVS	5	hyper velocity candidate
SEGUE2_XDM	6	extreme sdM star
SEGUE2_MII	7	M giant
SEGUE2_HHV	8	High-velocity halo star candidate
SEGUE2_BHB	13	Blue horizontal branch star
SEGUE2_CWD	17	Cool white dwarf
SEGUE2_CHECKED	31	was a checked object

More detailed information about the selection criteria for SEGUE-2 is available on the archived SEGUE Target Selection page.

SEGUE2_TARGET2: SEGUE-2 secondary target bits

Bit Name	Binary Digit	Description
LIGHT_TRAP	0	light trap hole
SEGUE2_REDDENING	1	reddening standard
SEGUE2_TEST	2	test target
SEGUE2_QA*	3	repeat target across plates
SKY	4	empty area for sky-subtraction
SEGUE2_SPECPHOTO	5	spectrophotometric star
GUIDE_STAR	6	guide star
BUNDLE_HOLE	7	bundle hole
QUALITY_HOLE	8	quality hole
HOT_STD	9	hot standard
SEGUE2_CLUSTER	10	SEGUE-2 stellar cluster target
SEGUE2_STETSON	11	Stetson standard target
SEGUE2_CHECKED	31	was a checked object

*QA duplicate observations are not currently marked in SEGUE2_TARGET2 bitmasks. These are only marked in sourcetype in SpecObjAll.

SPECIAL_TARGET1: SDSS special program target bits

Bit Name	Binary Digit	Description
APBIAS	0	aperture bias target
LOWZ_ANNIS	1	low-redshift cluster galaxy
QSO_M31	2	QSO in M31
COMMISSIONING_STAR	3	star in commissioning
DISKSTAR	4	thin/thick disk star
FSTAR	5	F-stars
HYADES_MSTAR	6	M-star in Hyades
LOWZ_GALAXY	7	low-redshift galaxy
DEEP_GALAXY_RED	8	deep LRG
DEEP_GALAXY_RED_II	9	deep LRG
BCG	10	brightest cluster galaxy
MSTURNOFF	11	main sequence turnoff
ORION_BD	12	Brown dwarf in Orion
ORION_MSTAR_EARLY	13	Early-type M-star (M0-3) in Orion
ORION_MSTAR_LATE	14	Late-type M-star (M4-) in Orion
SPECIAL_FILLER	15	filler from completeTile, check primtarget for details
PHOTOZ_GALAXY	16	test galaxy for photometric redshifts
PREBOSS_QSO	17	QSO for pre-BOSS observations
PREBOSS_LRG	18	QSO for pre-BOSS observations
PREMARVELS	19	pre-MARVELS stellar target
SOUTHERN_EXTENDED	20	simple extension of southern targets
SOUTHERN_COMPLETE	21	completion in south of main targets
U_PRIORITY	22	priority u-band target
U_EXTRA	23	extra u-band target
U_EXTRA2	24	extra u-band target
FAINT_LRG	25	faint LRG in south
FAINT_QSO	26	faint QSO in south
BENT_RADIO	27	bent double-lobed radio source
STRAIGHT_RADIO	28	straight double-lobed radio source
VARIABLE_HIPRI	29	high priority variable
VARIABLE_LOPRI	30	low priority variable
ALLPSF	31	i < 19.1 point sources
ALLPSF_NONSTELLAR	32	i < 19.1 point sources off stellar locus
ALLPSF_STELLAR	33	i < 19.1 point sources on stellar locus
HIPM	34	high proper motion
TAURUS_STAR	35	star on Taurus or reddening plate
TAURUS_GALAXY	36	galaxy on Taurus or reddening plate
PERSEUS	37	galaxy in Perseus-Pisces
LOWZ_LOVEDAY	38	low redshift galaxy selected by Loveday

SPECIAL_TARGET2: Secondary target mask bits in SDSS-I, -II

These bitmask values are appropriate for the following bitmasks used for SDSS-I and -II: LEGACY_TARGET2, SPECIAL_TARGET2 or SECTARGET.

Bit Name	Binary Digit	Description
LIGHT_TRAP	0	hole drilled for bright star, to avoid scattered light
REDDEN_STD	1	reddening standard star
TEST_TARGET	2	a test target
QA	3	quality assurance target
SKY	4	sky target
SPECTROPHOTO_STD	5	spectrophotometry standard (typically an F-star)
GUIDE_STAR	6	guide star hole
BUNDLE_HOLE	7	fiber bundle hole
QUALITY_HOLE	8	hole drilled for plate shop quality measurements
HOT_STD	9	hot standard star
SOUTHERN_SURVEY	31	a segue or southern survey target

BOSS_TARGET1: BOSS survey primary target selection flags

Bit Name	Binary Digit	Description
GAL_LOZ	0	low-z lrgs
GAL_CMASS	1	dperp > 0.55, color-mag cut
GAL_CMASS_COMM	2	dperp > 0.55, commissioning color-mag cut
GAL_CMASS_SPARSE	3	GAL_CMASS_COMM & (!GAL_CMASS) & (i < 19.9) sparsely sampled
GAL_LODPERP_DEPRECATED	5	(DEPRECATED) Same as hiz but between dperp00 and dperp0
SDSS_KNOWN	6	Matches a known SDSS spectra
GAL_CMASS_ALL	7	GAL_CMASS and the entire sparsely sampled region
GAL_IFIBER2_FAINT	8	ifiber2 > 21.5, extinction corrected. Used after Nov 2010
QSO_CORE	10	restrictive qso selection: commissioning only
QSO_BONUS	11	permissive qso selection: commissioning only
QSO_KNOWN_MIDZ	12	known qso between [2.2,9.99]
QSO_KNOWN_LOHIZ	13	known qso outside of miz range. never target
QSO_NN	14	Neural Net that match to sweeps/pass cuts
QSO_UKIDSS	15	UKIDSS stars that match sweeps/pass flag cuts
QSO_KDE_COADD	16	kde targets from the stripe82 coadd
QSO_LIKE	17	likelihood method
QSO_FIRST_BOSS	18	FIRST radio match
QSO_KDE	19	selected by kde+chi2
STD_FSTAR	20	standard f-stars
STD_WD	21	white dwarfs
STD_QSO	22	qso
TEMPLATE_GAL_PHOTO	32	galaxy templates
TEMPLATE_QSO_SDSS1	33	QSO templates
TEMPLATE_STAR_PHOTO	34	stellar templates
TEMPLATE_STAR_SPECTRO	35	stellar templates (spectroscopically known)
QSO_CORE_MAIN	40	Main survey core sample
QSO_BONUS_MAIN	41	Main survey bonus sample
QSO_CORE_ED	42	Extreme Deconvolution in Core
QSO_CORE_LIKE	43	Likelihood that make it into core
QSO_KNOWN_SUPPZ	44	known qso between [1.8,2.15]

EBOSS_TARGET0: SEQUELS, TDSS and SPIDERS target selection flags

Bit Name	Binary Digit	Description
DO_NOT_OBSERVE	0	Don’t put a fiber on this object
LRG_IZW	1	LRG selection in i/z/W plane
LRG_RIW	2	LRG selection in r/i/W plan with (i-z) cut
QSO_EBOSS_CORE	10	QSOs in XDQSOz+WISE selection for clustering
QSO_PTF	11	QSOs with variability in PTF imaging
QSO_REOBS	12	QSOs from BOSS to be reobserved
QSO_EBOSS_KDE	13	KDE-selected QSOs (sequels only)
QSO_EBOSS_FIRST	14	Objects with FIRST radio matches
QSO_BAD_BOSS	15	QSOs from BOSS with bad spectra
QSO_BOSS_TARGET	16	Known TARGETS from BOSS with spectra
QSO_SDSS_TARGET	17	Known TARGETS from SDSS with spectra
QSO_KNOWN	18	Known QSOs from previous surveys
DR9_CALIB_TARGET	19	Target found in DR9-calibrated imaging
SPIDERS_RASS_AGN	20	RASS AGN sources
SPIDERS_RASS_CLUS	21	RASS Cluster sources
SPIDERS_ERASS_AGN	22	ERASS AGN sources
SPIDERS_ERASS_CLUS	23	ERASS Cluster sources
TDSS_A	30	Main PanSTARRS selection for TDSS
TDSS_FES_DE	31	TDSS Few epoch spectroscopy
TDSS_FES_DWARFC	32	TDSS Few epoch spectroscopy
TDSS_FES_NQHISN	33	TDSS Few epoch spectroscopy
TDSS_FES_MGII	34	TDSS Few epoch spectroscopy
TDSS_FES_VARBAL	35	TDSS Few epoch spectroscopy
SEQUELS_PTF_VARIABLE	40	Variability objects from PTF
SEQUELS_COLLIDED	41	Collided galaxies from BOSS

EBOSS_TARGET1: eBOSS, TDSS and SPIDERS target selection flags

Bit Name	Binary Digit	Description
DO_NOT_OBSERVE	0	Don’t put a fiber on this object
LRG1_WISE	1	LRG selection in i/z/W plane
LRG1_IDROP	2	LRG selection in r/i/W plan with (i-z) cut
LRG_KNOWN	3	LRG selection in r/i/W plan with (i-z) cut
QSO1_VAR_S82	9	Variability-selected QSOs in the repeated Stripe 82 imaging
QSO1_EBOSS_CORE	10	QSOs in XDQSOz+WISE selection for clustering
QSO1_PTF	11	QSOs with variability in PTF imaging
QSO1_REOBS	12	QSOs from BOSS to be reobserved
QSO1_EBOSS_KDE	13	KDE-selected QSOs (sequels only)
QSO1_EBOSS_FIRST	14	Ojbects with FIRST radio matches
QSO1_BAD_BOSS	15	QSOs from BOSS with bad spectra
QSO_BOSS_TARGET	16	Known TARGETS from BOSS with spectra
QSO_SDSS_TARGET	17	Known TARGETS from SDSS with spectra
QSO_KNOWN	18	Known QSOs from previous surveys
EFEDS_EROSITA_AGN	19	Point-like eROSITA source – target expected to be AGN, star or compact object
EFEDS_EROSITA_CLUS	20	Extended eROSITA source – target expected to be galaxy cluster member
EFEDS_HSC_HIZQSO	22	High redshift QSO candidate from HSC photometry
EFEDS_HSC_WERGS	23	WISE bright, optically faint radio galaxy from HSC photometry
EFEDS_HSC_REDAGN	24	Obscured AGN selected in HSC+WISE and/or HSC+VIKING photometry
EFEDS_COSMOQSO	25	UVX/variability QSO selection
EFEDS_WISE_AGN	26	WISE colour-selected AGN
EFEDS_WISE_VARAGN	27	WISE variability-selected AGN
EFEDS_XMMATLAS	28	X-ray selected target from the XMM-ATLAS coverage in the eFEDS field
EFEDS_CSC2	29	X-ray selected target from the Chandra Source Catalogue in the eFEDS field
TDSS_TARGET	30	Target for TDSS (subclass found in eboss_target2)
SPIDERS_TARGET	31	Target for SPIDERS (subclass found in eboss_target2)
S82X_TILE1	32
S82X_TILE2	33
S82X_TILE3	34
EFEDS_SDSSWISE_QSO	35	QSO candidate from UMAP classification of SDSS+WISE photometric sources
EFEDS_GAIAWISE_QSO	36	QSO candidate from RF classification of Gaia-unWISE sources
EFEDS_KIDS_QSO	37	QSO candidate from classification of KiDS+VIKING DR3 sources
EFEDS_SDSS_REDMAPPER	38	RedMaPPER galaxy cluster candidate with SDSS photometry
EFEDS_HSC_REDMAPPER	39	RedMaPPER galaxy cluster candidate with HSC photometry
ELG_TEST1	40	Test targets for ELG selection
ELG1_EBOSS	41	Standard DECALS ELG target selection
ELG1_EXTENDED	42	Extended DECALS ELG target selection
ELG1_SGC	43	Final ELG selection, SGC data
ELG1_NGC	44	Final ELG selection, NGC data
EFEDS_GAIA_WD	45	Gaia-selected WD binary candidate in the region between the ZAMS and the WD sequence
EFEDS_GAIAGALEX_WD	46	Gaia-GALEX UV excess source – expected to be compact binary harbouring a WD
EFEDS_VAR_WD	47	Optical variability selected WD candidate
STD_FSTAR	50	standard f-stars
STD_WD	51	white dwarfs
STD_QSO	52	qso

EBOSS_TARGET2: eBOSS, TDSS and SPIDERS special target selection flags

Bit Name	Binary Digit	Description
SPIDERS_RASS_AGN	0	RASS AGN sources
SPIDERS_RASS_CLUS	1	RASS Cluster sources
SPIDERS_ERASS_AGN	2	ERASS AGN sources
SPIDERS_ERASS_CLUS	3	ERASS Cluster sources
SPIDERS_XMMSL_AGN	4	XMM Slew survey
SPIDERS_XCLASS_CLUS	5	XMM serendipitous clusters
TDSS_A	20	Main PanSTARRS selection for TDSS
TDSS_FES_DE	21	QSOs with disk emitter broad line profiles
TDSS_FES_DWARFC	22	dwarf carbon stars
TDSS_FES_NQHISN	23	QSOs with previous spectra of S/N>25
TDSS_FES_MGII	24	binary AGN candidate
TDSS_FES_VARBAL	25	broad absorption line QSOs
TDSS_B	26	Main TDSS SES version B
TDSS_FES_HYPQSO	27	strongly variable QSOs
TDSS_FES_HYPSTAR	28	strongly variable star
TDSS_FES_WDDM	29	white dwarf/M dwarf pairs with Halpha emission
TDSS_FES_ACTSTAR	30	late-M and L stars with Halpha emission
TDSS_CP	31	TDSS in common with CORE/PTF
TDSS_S82X_FES_HYPQSO	32
TDSS_S82X_SESQSO	33
TDSS_RQS1	34	quasars targeted at high priority
TDSS_RQS2	35	quasars targeted at medium priority
TDSS_RQS3	36	quasars targeted at lower priority
TDSS_RQS2v	37	variability selected quasars targeted at medium priority
TDSS_RQS3v	38	variability selected quasars targeted at lower priority
ELG_SCUSS_TEST1	40	SCUSS selection for test1 ELG plates
ELG_DES_TEST1	41	DES selection for test1 ELG plates
ELG_DESI_TEST1	42	DESI selection for test1 ELG plates
ELG_SDSS_TEST1	43	SDSS-only selection for test1 ELG plates
ELG_UGRIZW_TEST1	44	WISE selection for test1 ELG plates
ELG_UGRIZWbright_TEST1	45	WISE selection for test1 ELG plates
ELG_GRIW_TEST1	46	WISE selection for test1 ELG plates
ELG_DECALS_TEST1	47	DECALS ELG selection, added sept 2015
ELG1_SGC	48	repeated bit from eboss_target1 for tiling purposes
ELG1_NGC	49	repeated bit from eboss_target1 for tiling purposes
S82X_BRIGHT_TARGET	50
S82X_XMM_TARGET	51
S82X_WISE_TARGET	52
S82X_SACLAY_VAR_TARGET	53
S82X_SACLAY_BDT_TARGET	54
S82X_SACLAY_HIZ_TARGET	55
S82X_RICHARDS15_PHOTOQSO_TARGET	56
S82X_PETERS15_COLORVAR_TARGET	57
S82X_LSSTZ4_TARGET	58
S82X_UNWISE_TARGET	59
S82X_GTRADMZ4_TARGET	60
S82X_CLAGN1_TARGET	61
S82X_CLAGN2_TARGET	62

ANCILLARY_TARGET1: Objects selected as BOSS Ancillary Targets

The presence of a nonzero value for this target flag indicates that the object was selected through one or more of the BOSS ancillary target selection programs.
If you don’t see the ancillary target bit you’re looking for here, try the other ancillary target flag parameter, ANCILLARY_TARGET2.

Bit Name	Binary Digit	Description
AMC	0	Candidate Am CVn variables in Stripe 82
FLARE1	1	Flaring M stars in Stripe 82 (year 1 targets)
FLARE2	2	Flaring M stars in Stripe 82 (year 2 targets)
HPM	3	High Proper Motion stars in Stripe 82
LOW_MET	4	Low-metallicity M dwarfs in Stripe 82
VARS	5	Unusual variable objects (colors outside the stellar and quasar loci) in Stripe 82
BLAZGVAR	6	A flag used in a pilot version of the ancillary targeting program High-Energy Blazars and Optical Counterparts to Gamma-Ray Sources; no longer used
BLAZR	7	A flag used in a pilot version of the ancillary targeting program High-Energy Blazars and Optical Counterparts to Gamma-Ray Sources; no longer used
BLAZXR	8	A target that might have a match with a Fermi source, but which is now below the detection limits of the early Fermi source catalogs
BLAZXRSAM	9	A flag used in a pilot version of the ancillary targeting program High-Energy Blazars and Optical Counterparts to Gamma-Ray Sources; no longer used
BLAZXRVAR	10	A flag used in a pilot version of the ancillary targeting program High-Energy Blazars and Optical Counterparts to Gamma-Ray Sources; no longer used
XMMBRIGHT	11	An object that matches a serendipitous x-ray source from the Second XMM-Newton Serendipitous Source Catalog (2XMMi), with bright `i magnitudes (i < 20.5) and bright 2-12 keV fluxes (f_{2-12 keV} > 5 × 10^-14 ergcm^-2s^-1)`
XMMGRIZ	12	An object that matches a serendipitous x-ray source from the Second XMM-Newton Serendipitous Source Catalog (2XMMi), with outlier SDSS colors (`g` – `r > 1.2 or r – i > 1.0 or i – z > 1.4)`
XMMHR	13	An object that matches a serendipitous x-ray source from the Second XMM-Newton Serendipitous Source Catalog (2XMMi), with unusual hardness ratios in the HR2-HR3 plane
XMMRED	14	An object that matches a serendipitous x-ray source from the Second XMM-Newton Serendipitous Source Catalog (2XMMi) with highly red SDSS colors (`g` – `i` > 1.0)
FBQSBAL	15	Broad absorption line (BAL) quasar with spectrum from the FIRST Bright Quasar Survey
LBQSBAL	16	Broad absorption line (BAL) quasar with spectrum from the Large Bright Quasar Survey
ODDBAL	17	Broad absorption line (BAL) quasar with various unusual properties (selected by hand)
OTBAL	18	Photometrically-selected overlapping-trough (OT) broad absorption line (BAL) quasar
PREVBAL	19	Broad absorption line (BAL) quasar with prior spectrum from SDSS-I/-II
VARBAL	20	Photometrically-selected candidate broad absorption line (BAL) quasar
BRIGHTGAL	21	Bright (r < 16) galaxies whose spectra were missed by the original SDSS spectroscopic survey
QSO_AAL	22	Radio-quiet variable quasar candidates with one absorption system associated with the quasar (v ≤ 5000 km/s in the quasar rest frame)
QSO_AALS	23	Radio-quiet variable quasar candidates with multiple absorption systems (associated and/or intervening)
QSO_IAL	24	Radio-quiet variable quasar candidates with one absorption system in the intervening space along our line-of-sight (v > 5000 km/s in the quasar rest frame)
QSO_RADIO	25	Radio-loud variable quasar candidates with multiple absorption systems (associated and/or intervening)
QSO_RADIO_AAL	26	Radio-loud variable quasar candidates with one absorption system associated with the quasar (v ≤ 5000 km/s in the quasar rest frame)
QSO_RADIO_IAL	27	Radio-loud variable quasar candidates with one absorption system in the intervening space along our line-of-sight (v > 5000 km/s in the quasar rest frame)
QSO_NOAALS	28	Radio-quiet variable quasar candidates with no associated absorption systems and multiple intervening absorption systems
QSO_GRI	29	Candidate high-redshift quasar (z > 3.6), selected in `gri` color space
QSO_HIZ	30	Candidate high-redshift quasar (z > 5.6), detected only in SDSS i and z filters.
QSO_RIZ	31	Candidate high-redshift quasar (z > 4.5), selected in `riz` color space
RQSS_SF	32	Candidate reddened quasar ( E(B-V)) > 0.5 ), selected from an SDSS primary catalog object matched with FIRST catalog data
RQSS_SFC	33	Candidate reddened quasar ( E(B-V)) > 0.5 ), selected from an SDSS child catalog object matched with FIRST catalog data
RQSS_STM	34	Candidate reddened quasar ( E(B-V)) > 0.5 ), selected from an SDSS primary catalog object matched with 2MASS catalog data
RQSS_STMC	35	Candidate reddened quasar ( E(B-V)) > 0.5 ), selected from an SDSS child catalog object matched with 2MASS catalog data
SN_GAL1	36	Likely host galaxy for an SDSS-II supernova, with the BOSS fiber assigned to the galaxy closest to the supernova’s position
SN_GAL2	37	Likely host galaxy for an SDSS-II supernova, with the BOSS fiber assigned to the second-closest galaxy
SN_GAL3	38	Likely host galaxy for an SDSS-II supernova, with the BOSS fiber assigned to the third-closest galaxy
SN_LOC	39	Likely host galaxy for an SDSS-II supernova, with the BOSS fiber assigned to the position of the original supernova
SPEC_SN	40	Likely host galaxy for an SDSS-II supernova, where the original supernova was identified from SDSS spectroscopic data
SPOKE	41	Widely-separated binary systems in which both stars are low-mass (spectral class M)
WHITEDWARF_NEW	42	White dwarf candidate whose spectrum had not been observed previously by the SDSS
WHITEDWARF_SDSS	43	White dwarf candidate with a pre-existing SDSS spectrum
BRIGHTERL	44	Bright L dwarf candidate (`i`_PSF < 19.5, `i`_PSF – `z`_PSF) > 1.14)
BRIGHTERM	45	Bright M dwarf candidate (`i`_PSF < 19.5, `i`_PSF – `z`_PSF) < 1.14)
FAINTERL	46	Faint L dwarf candidate (`i`_PSF > 19.5, `i`_PSF – `z`_PSF) > 1.14)
FAINTERM	47	Faint M dwarf candidate (`i`_PSF > 19.5, `i`_PSF – `z`_PSF) < 1.14)
RED_KG	48	Giant star in the Milky Way outer halo
RVTEST	49	Known giant star selected as a test of radial velocity measurement techniques
BLAZGRFLAT	50	Candidate optical counterpart to a Fermi gamma-ray source, within 2″ of a CRATES radio source and within a Fermi error ellipse
BLAZGRQSO	51	Candidate optical counterpart to a Fermi gamma-ray source, within 2″ of a FIRST radio source and within a Fermi error ellipse
BLAZGX	52	Candidate optical counterpart to a Fermi gamma-ray source, within 1′ of a ROSAT All-Sky Survey x-ray source and within a Fermi error ellipse, and without typical signs of blazar activity
BLAZGXQSO	53	Candidate optical counterpart to a Fermi gamma-ray source, within 1′ of a ROSAT All-Sky Survey x-ray source and within a Fermi error ellipse
BLAZGXR	54	Candidate optical counterpart to a Fermi gamma-ray source, with matches in both radio and x-ray wavelengths: within 1′ of a ROSAT All-Sky Survey x-ray source, within 2″ of a FIRST radio source, and within a Fermi error ellipse
BLUE_RADIO	56	Likely star-forming AGN: blue galaxies that match with FIRST radio sources
CHANDRAV1	57	An object with a Chandra match that is likely to be a star-forming galaxy with black hole accretion
CXOBRIGHT	58	An object that matches a serendipitous x-ray source from the Chandra Source Catalog, with bright `i` magnitudes (`i` < 20.0) and bright 2-8 keV fluxes (`f`_{2-8 keV} > 5 x 10^-14 ergcm^-2s^-1)
CXOGRIZ	59	An object that matches a serendipitous x-ray source from the Chandra Source Catalog, with outlier SDSS colors (`g` – `r` > 1.2 or `r` – `i` > 1.0 or `i` – `z` > 1.4)
CXORED	60	An object that matches a serendipitous x-ray source from the Chandra Source Catalog, with highly red SDSS colors (`g` – `i` > 1.0)
ELG	61	Luminous blue galaxy with `g`_PSF < 22.5
GAL_NEAR_QSO	62	A galaxy that lies between 0.006′ and 1′ of the line-of-sight for a spectroscopically-confirmed quasar
MTEMP	63	Template M-stars observed as a comparison sample in Stripe 82

ANCILLARY_TARGET2: More objects selected as BOSS Ancillary Targets

Bit Name	Binary Digit	Description
HIZQSO82	0	Quasar candidate in SDSS stripe 82 selected with UKIDSS YJHK photometry using a more relaxed color cut
HIZQSOIR	1	Quasar candidate selected with UKIDSS YJHK photometry
KQSO_BOSS	2	Quasar candidate selected with UKIDSS YJHK photometry
QSO_VAR	3	Candidate quasar in Stripe 82 survey area, selected from variability alone
QSO_VAR_FPG	4	Candidate quasar in Stripe 82 survey area, selected from variability alone
RADIO_2LOBE_QSO	5	Object near the midpoint of a double-lobed object identified in FIRST Catalogs
STRIPE82BCG	6	The brightest cluster member of a galaxy cluster or group identified in the Stripe 82 survey area
QSO_SUPPZ	7	A subset of SDSS-I/-II quasars with 1.8 < z < 2.15 that were reobserved with the BOSS spectrograph to measure metal absorption free of any effects from the Lyman-α forest (no longer used in DR12)
QSO_VAR_SDSS	8	Quasars selected by photometric variability in the overlap regions between stripes of SDSS-I/-II imaging, accounting for roughly 30% of the total BOSS footprint (no longer used in DR12)
QSO_WISE_SUPP	9	Quasar targets selected on their mid-infrared colors from the WISE satellite, thought to be z>2.2 quasars, as a supplement to the primary BOSS quasar sample (no longer used in DR12)
QSO_WISE_FULL_SKY	10	Quasar selected from the WISE All-Sky Survey
XMMSDSS	11	Hard x-ray-selected AGN from XMM
IAMASERS	12	Known or potential maser
DISKEMITTER_REPEAT	13	Candidate massive binary black hole pair
WISE_BOSS_QSO	14	Quasar identified in the WISE All-Sky Survey
QSO_XD_KDE_PAIR	15	Candidate closely-separated quasar pair
CLUSTER_MEMBER	16	Member of a galaxy cluster selected from ROSAT All-Sky Survey data
SPOKE2	17	Candidate binary pair in which one star is an M dwarf
FAINT_ELG	18	Blue star-forming galaxy selected from CFHT-LS photometry
PTF_GAL	19	A nearby galaxy identified in PTF imaging with an SDSS counterpart
QSO_STD	20	A standard star targeted to improve BOSS spectrophotometric calibration
HIZ_LRG	21	A candidate z > 0.6 LRG, selected using a narrower r-i color constraint and observed at higher priority
LRG_ROUND3	22	A candidate z > 0.6 LRG, selected using a broader r-i color constraint and observed at lower priority
WISE_COMPLETE	23	Galaxy in the same redshift range as the BOSS CMASS sample, but selected with a more relaxed color cut
TDSS_PILOT	24	Objects identified from PanSTARRS imaging using the selection criteria described on the BOSS ancillary target page
SPIDERS_PILOT	25	Objects identified from PanSTARRS imaging using the selection criteria described on the BOSS ancillary target page
TDSS_SPIDERS_PILOT	26	Objects identified using both sets of selection criteria for TDSS_PILOT and SPIDERS_PILOT
QSO_VAR_LF	27	Candidate quasar in stripe 82, selected by color and variability
TDSS_PILOT_PM	28	Objects identified using X-ray imaging that has high proper motions
TDSS_PILOT_SNHOST	29	Objects identified in PanSTARRS imaging that showed transient behavior in extended objects
FAINT_HIZ_LRG	30	Candidate galaxy in the redshift range 0.6 < z < 0.9, defined by color cuts
QSO_EBOSS_W3_ADM	31	Candidate quasar, defined by one of the complex color cuts described below and recorded in the W3bitmask parameter of the original targeting file
XMM_PRIME	32	Candidate AGN identified from the XMM-XXL survey observed at higher priority
XMM_SECOND	33	Candidate AGN identified from the XMM-XXL survey observed at lower priority
SEQUELS_ELG	34	Emission-line galaxy targeted by the SEQUELS program
GES	35	Star observed by the Gaia/ESO Survey (GES)
SEGUE1	36	Star observed by the prior SDSS spectroscopic SEGUE-1 survey
SEGUE2	37	Star observed by SEGUE-2
SDSSFILLER	38	Star in the GES survey area, targeted from prior SDSS photometry
SEQUELS_ELG_LOWP	39	Emission-line galaxy targeted by the SEQUELS program at lower priority
25_ORI_WISE	40	WISE-selected target near the star 25 Ori
25_ORI_WISE_W3	41	WISE-selected target near the star 25 Ori, selected from data in the W3 band
KOEKAP_STAR	42	WISE-selected source in the star-forming region Kappa Ori, selected from WISE infrared excess
KOE2023_STAR	43	WISE-selected source in the star-forming region NGC 2023, selected from WISE infrared excess
KOE2068_STAR	44	WISE-selected source in the star-forming region NGC 2068, selected from WISE infrared excess
KOE2023BSTAR	45	Other WISE-selected source in the star-forming region NGC 2023
KOE2068BSTAR	46	Other WISE-selected source in the star-forming region NGC 2068
KOEKAPAPBSTAR	47	Other WISE-selected source in the star-forming region Kappa Ori
COROTGESAPOG	48	Star observed by both the CoRoT survey and by APOGEE
COROTGES	49	Star observed by both CoRoT and GES
APOGEE	50	Star in the CoRoT survey area, not observed by CoRoT but with an APOGEE spectrum
2MASSFILL	51	Star in the CoRoT survey area targeted from 2MASS photometry
TAU_STAR	52	Spitzer-selected source in the Taurus Heiles 2 molecular cloud
SEQUELS_TARGET	53	A target from the SEQUELS program (no longer used, replaced by EBOSS_TARGET0 flag)
RM_TILE1	54	AGN selected for reverberation mapping study at high priority
RM_TILE2	55	AGN selected for reverberation mapping study at lower priority
QSO_DEEP	56	Candidate quasar selected by time variability
LBG	57	Candidate Lyman-break galaxy selected by color
ELAIS_N1_LOFAR	58	LOFAR source selected with RMS noise criteria
ELAIS_N1_FIRST	59	Source detected in the FIRST radio catalog
ELAIS_N1_GMRT_GARN	60	Source identified from deeper GMRT radio data
ELAIS_N1_GMRT_TAYLOR	61	Fainter source identified from deeper GMRT radio data
ELAIS_N1_JVLA	62	Very faint source detected in JVLA radio data

BOSSTILE_STATUS: BOSS tiling code status bits

Bit Name	Binary Digit	Description
TILED	0	assigned a fiber
NAKED	1	not in area covered by tiles
BOSSTARGET	2	in the high priority set of targets
DECOLLIDED	3	in the decollided set of high priority
ANCILLARY	4	in the lower priority, ancillary set
POSSIBLE_KNOCKOUT	5	knocked out of at least one tile by BOSSTARGET
IGNORE_PRIORITY	6	priority exceeds max (ANCILLARY only)
TOOBRIGHT	7	fibermag too bright
BLUEFIBER	8	allocate this object a blue fiber
CENTERPOST	9	92 arcsec collision with center post
REPEAT	10	included on more than one tile
FILLER	11	was a filler (not normal repeat)
NOT_TILED_TARGET	12	though in input file, not a tiled target
OUT_OF_BOUNDS	13	outside bounds for this sort of target (for restricted QSO geometry, e.g.)
BAD_CALIB_STATUS	14	bad CALIB_STATUS
PREVIOUS_CHUNK	15	included because not tiled in previous overlapping chunk
KNOWN_OBJECT	16	galaxy has known redshift
DUPLICATE	17	trimmed as a duplicate object (only checked if not trimmed for any other reason)
DUPLICATE_PRIMARY	18	has associated duplicate object that were trimmed (but this one is kept)
DUPLICATE_TILED	19	trimmed as a duplicate object, and its primary was tiled
TOOFAINT	20	trimmed because it was fainter than the ifiber2mag limit
SUPPLEMENTARY	21	supplementary targets tiles after the ancillaries (subset of ancillaries)

FLUXMATCH_STATUS: Flags from flux-based matching to SDSS photometry

Bit Name	Binary Digit	Description
ORIGINAL_FLUXMATCH	0	used the original positional match (which exists)
FIBER_FLUXMATCH	1	flagged due to fiberflux/aperflux issue
NONMATCH_FLUXMATCH	2	flagged due to non-match
NOPARENT_FLUXMATCH	3	no overlapping parent in primary field
PARENT_FLUXMATCH	4	overlapping parent has no children, so used it
BRIGHTEST_FLUXMATCH	5	picked the brightest child

APOGEE_TARGET1: 1/2 APOGEE target bits

Bit Name	Binary Digit	Description
APOGEE_FAINT	0	Star selected in faint bin of cohort
APOGEE_MEDIUM	1	Star selected in medium bin of cohort
APOGEE_BRIGHT	2	Star selected in bright bin of cohort
APOGEE_IRAC_DERED	3	Star selected using RJCE-IRAC dereddening
APOGEE_WISE_DERED	4	Star selected using RJCE-WISE dereddening
APOGEE_SFD_DERED	5	Selected using SFD E(B-V) dereddening
APOGEE_NO_DERED	6	Star selected using no dereddening
APOGEE_WASH_GIANT	7	Selected as giant star via Washington+DDO51 photometry
APOGEE_WASH_DWARF	8	Selected as dwarf star via Washington+DDO51 photometry
APOGEE_SCI_CLUSTER	9	Probable stellar cluster member
APOGEE_EXTENDED	10	Extended object
APOGEE_SHORT	11	Short cohort target star
APOGEE_INTERMEDIATE	12	Intermediate cohort target star
APOGEE_LONG	13	Long cohort target star
—	14	—
APOGEE_SERENDIPITOUS	15	Serendipitous interesting target to re-observe
APOGEE_FIRST_LIGHT	16	“First Light” cluster target
APOGEE_ANCILLARY	17	An ancillary program target (particular program specified in other bits, see below)
APOGEE_M31_CLUSTER	18	M31 cluster target (ancillary)
APOGEE_MDWARF	19	M dwarf star selected for RV/metallicity program (ancillary)
APOGEE_HIRES	20	Star with optical hi-res spectra (ancillary)
APOGEE_OLD_STAR	21	Selected as old star (ancillary)
APOGEE_DISK_RED_GIANT	22	Disk red giant star (ancillary)
APOGEE_KEPLER_EB	23	Eclipsing binary star from Kepler (ancillary)
APOGEE_GC_PAL1	24	Star in Pal1 globular cluster (ancillary)
APOGEE_MASSIVE_STAR	25	Massive star (ancillary)
APOGEE_SGR_DSPH	26	Sagittarius dwarf galaxy member
APOGEE_KEPLER_SEISMO	27	Kepler astroseismology program target star
APOGEE_KEPLER_HOST	28	Kepler planet-host program target star
APOGEE_FAINT_EXTRA	29	Selected as faint target for low target density field
APOGEE_SEGUE_OVERLAP	30	Selected because of overlap with SEGUE survey
APOGEE_CHECKED	31	This object was checked for APOGEE target selection.

APOGEE_TARGET2: 2/2 APOGEE target bits

Bit Name	Binary Digit	Description
—	0	—
APOGEE_FLUX_STANDARD	1	Flux standard
APOGEE_STANDARD_STAR	2	Stellar abundance and/or parameters standard
APOGEE_RV_STANDARD	3	Stellar radial velocity standard
SKY	4	Blank sky position
—	5	—
—	6	—
—	7	—
—	8	—
APOGEE_TELLURIC	9	Hot (telluric) standard star
APOGEE_CALIB_CLUSTER	10	Known calibration cluster member star
APOGEE_BULGE_GIANT	11	Probable giant star in Galactic bulge
APOGEE_BULGE_SUPER_GIANT	12	Probable supergiant star in Galactic bulge
APOGEE_EMBEDDEDCLUSTER_STAR	13	Young embedded cluster member (ancillary)
APOGEE_LONGBAR	14	Probable RC star in long bar (ancillary)
APOGEE_EMISSION_STAR	15	Emission-line star (ancillary)
APOGEE_KEPLER_COOLDWARF	16	Kepler cool dwarf or subgiant (ancillary)
APOGEE_MIRCLUSTER_STAR	17	MIR-detected candidate cluster member (ancillary)
APOGEE_RV_MONITOR_IC348	18	IC 348 star monitored for RV variability (ancillary)
APOGEE_RV_MONITOR_KEPLER	19	Kepler planet host or binary monitored for RV variability (ancillary)
APOGEE_GES_CALIBRATE	20	Gaia-ESO calibrator
APOGEE_BULGE_RV_VERIFY	21	Bulge commissioning RV verification
APOGEE_1M_TARGET	22	Targeted with the 1-m telescope
—	23	—
—	24	—
—	25	—
—	26	—
—	27	—
—	28	—
—	29	—
—	30	—
APOGEE_CHECKED	31	This object was checked for APOGEE target selection.

APOGEE2_TARGET1: 1/3 APOGEE-2 target bits

Bit Name	Bit number	Description
APOGEE2_ONEBIN_GT_0_5	0	Selected in single (J−Ks)0>0.5 color bin
APOGEE2_TWOBIN_0_5_TO_0_8	1	Selected in “blue” 0.5<(J−Ks)0<0.8 color bin
APOGEE2_TWOBIN_GT_0_8	2	Selected in “red” (J−Ks)0>0.8 color bin
APOGEE2_IRAC_DERED	3	Star selected using RJCE-IRAC dereddening
APOGEE2_WISE_DERED	4	Star selected using RJCE-WISE dereddening
APOGEE2_SFD_DERED	5	Selected using SFD E(B−V) dereddening
APOGEE2_NO_DERED	6	Star selected using no dereddening
APOGEE2_WASH_GIANT	7	Selected as giant star via Washington+DDO51 photometry
APOGEE2_WASH_DWARF	8	Selected as dwarf star via Washington+DDO51 photometry
APOGEE2_SCI_CLUSTER	9	Science cluster candidate member
APOGEE2_EXTENDED	10	Extended object
APOGEE2_SHORT	11	Short cohort target star
APOGEE2_MEDIUM	12	Intermediate cohort target star
APOGEE2_LONG	13	Long cohort target star
APOGEE2_NORMAL_SAMPLE	14	Selected as part of the random sample
APOGEE2_MANGA_LED	15	Star on a shared MaNGA-led design
APOGEE2_ONEBIN_GT_0_3	16	Selected in single (J−Ks)0>0.3 color bin
APOGEE2_WASH_NOCLASS	17	Selected because it has no W+D classification
APOGEE2_STREAM_MEMBER	18	Selected as confirmed halo tidal stream member
APOGEE2_STREAM_CANDIDATE	19	Selected as potential halo tidal stream member
APOGEE2_DSPH_MEMBER	20	Selected as confirmed dSph member (non Sgr)
APOGEE2_DSPH_CANDIDATE	21	Selected as potential dSph member (non Sgr) (based on photometry)
APOGEE2_MAGCLOUD_MEMBER	22	Selected as confirmed Mag Cloud member
APOGEE2_MAGCLOUD_CANDIDATE	23	Selected as potential Mag Cloud member (based on photometry)
APOGEE2_RRLYR	24	Selected as an RR Lyrae star
APOGEE2_BULGE_RC	25	Selected as a bulge candidate RC star
APOGEE2_SGR_DSPH	26	Sagittarius dwarf galaxy member
APOGEE2_APOKASC_GIANT	27	Selected as part of APOKASC “giant” sample
APOGEE2_APOKASC_DWARF	28	Selected as part of APOKASC “dwarf” sample
APOGEE2_FAINT_EXTRA	29	Selected as faint target for low target density field
APOGEE2_APOKASC	30	Selected as part of the APOKASC program (incl. seismic/gyro targets and others, both the Cygnus field and K2)
APOGEE2_CHECKED	31	This object was checked for APOGEE target selection.

APOGEE2_TARGET2: 2/3 APOGEE-2 target bits

Bit Name	Bit number	Description
—	0	—
APOGEE2_CCLOUD_AS4	1	California Cloud target
APOGEE2_STANDARD_STAR	2	Stellar parameters/abundance standard
APOGEE2_RV_STANDARD	3	Stellar RV standard
APOGEE2_SKY	4	Sky fiber
APOGEE2_EXTERNAL_CALIB	5	External survey calibration target
APOGEE2_INTERNAL_CALIB	6	Internal survey calibration target
APOGEE2_DISK_SUBSTRUCTURE_MEMBER	7	Bright time extension: outer disk substructure (Triand, GASS, and A13) members
APOGEE2_DISK_SUBSTRUCTURE_CANDIDATE	8	Bright time extension: outer disk substructure (Triand, GASS, and A13) candidates
APOGEE2_TELLURIC	9	Telluric calibrator target
APOGEE2_CALIB_CLUSTER	10	Selected as calibration cluster member
APOGEE2_K2_PLANETHOST	11	Planet host in the K2 field
APOGEE2_TIDAL_BINARY	12	Ancillary KOI Program (Simonian)
APOGEE2_LITERATURE_CALIB	13	Overlap with high-resolution literature studies
APOGEE2_GES_OVERLAP	14	Overlap with Gaia-ESO
APOGEE2_ARGOS_OVERLAP	15	Overlap with ARGOS
APOGEE2_GAIA_OVERLAP	16	Overlap with Gaia
APOGEE2_GALAH_OVERLAP	17	Overlap with GALAH
APOGEE2_RAVE_OVERLAP	18	Overlap with RAVE
APOGEE2_COMMIS_SOUTH_SPEC	19	Commissioning special targets for APOGEE-2S
APOGEE2_HALO_MEMBER	20	Bright time extension: halo member
APOGEE2_HALO_CANDIDATE	21	Bright time extension: halo candidate
APOGEE2_1M_TARGET	22	Selected as a 1-m target
APOGEE2_MOD_BRIGHT_LIMIT	23	Selected in a cohort with H>10 rather than H>7
APOGEE2_CIS	24	Carnegie program target
APOGEE2_CNTAC	25	Chilean community target
APOGEE2_EXTERNAL	26	Proprietary external target
APOGEE2_CVZ_AS4_OBAF	27	OBAF stars selected for multi-epoc observations Andrew T.
APOGEE2_CVZ_AS4_GI	28	Submitted program to be on CVZ plate (Known Planets, ATL, Tayar-Subgiant, Canas-Cool-dwarf)
APOGEE2_CVZ_AS4_CTL	29	Filler CTL star selected from the TESS Input Catalog
APOGEE2_CVZ_AS4_GIANT	30	Filler Giant selected with RPMJ
—	31	—

APOGEE2_TARGET3: 3/3 APOGEE-2 target bits

Bit Name	Bit number	Description
APOGEE2_KOI	0	Selected as part of the long cadence KOI study
APOGEE2_EB	1	Selected as part of the EB program
APOGEE2_KOI_CONTROL	2	Selected as part of the long cadence KOI “control sample”
APOGEE2_MDWARF	3	Selected as part of the M dwarf study
APOGEE2_SUBSTELLAR_COMPANIONS	4	Selected as part of the substellar companion search
APOGEE2_YOUNG_CLUSTER	5	Selected as part of the young cluster study (IN-SYNC)
APOGEE2_K2	6	Selected as part of the K2 program (BTX and Main Survey)
APOGEE2_OBJECT	7	This object is an APOGEE-2 target
APOGEE2_ANCILLARY	8	Selected as an ancillary target
APOGEE2_MASSIVE_STAR	9	Selected as part of the Massive Star program
APOGEE2_QSO	10	Ancillary QSO program
APOGEE2_CEPHEID	11	Ancillary Cepheid sparse targets
APOGEE2_LOW_AV_WINDOWS	12	Ancillary Deep Disk sample
APOGEE2_BE_STAR	13	Ancillary ASHELS sample
APOGEE2_YOUNG_MOVING_GROUP	14	Ancillary young moving group members
APOGEE2_NGC6791	15	Ancillary NGC 6791 star
APOGEE2_LABEL_STAR	16	Ancillary Cannon calibrator sample (Ness)
APOGEE2_FAINT_KEPLER_GIANTS	17	Ancillary APOKASC faint giants
APOGEE2_W345	18	Ancillary W3/4/5 star forming complex
APOGEE2_MASSIVE_EVOLVED	19	Ancillary massive/evolved star targets
APOGEE2_REDDENING_TARGETS	20	Ancillary extinction targets
APOGEE2_KEPLER_MDWARF_KOI	21	Ancillary M dwarf targets
APOGEE2_AGB	22	Ancillary AGB sample
APOGEE2_M33	23	Ancillary M33 Program (Anguiano)
APOGEE2_ULTRACOOL	24	Ancillary Ultracool Dwarfs Program (Burgasser)
APOGEE2_DISTANT_SEGUE_GIANTS	25	Ancillary Distant SEGUE Giants Program (Harding)
APOGEE2_CEPHEID_MAPPING	26	Ancillary Cepheid Mapping Program (Inno)
APOGEE2_SA57	27	Ancillary SA57 Kapteyn Field Program (Majewski)
APOGEE2_K2_MDWARF	28	Ancillary K2 M dwarf Program (Smith)
APOGEE2_RVVAR	29	Ancillary RV Variables Program (Troup)
APOGEE2_M31	30	Ancillary M31 Program (Zasowski)
—	31	—

APOGEE_EXTRATARG: APOGEE Extra Targeting Bits

This bit mask provides a convenient way to select only main survey targets (EXTRATARG==0) and identifies the main classes of other targets.

Bit Name	Binary Digit	Description
NOT_MAIN	0	Not main survey target
COMMISSIONING	1	Commissioning data
TELLURIC	2	Telluric target
APO1M	3	1m observation
DUPLICATE	4	Duplicate observation

APOGEE_PIXMASK: APOGEE pixel level mask bits

This bit mask describes the warnings and failures for pixels within the 1D spectra for APOGEE. The bits are set on a per-pixel basis.

Bit Name	Binary Digit	Description
BADPIX	0	Pixel marked as BAD in bad pixel mask
CRPIX	1	Pixel marked as cosmic ray in ap3d
SATPIX	2	Pixel marked as saturated in ap3d
UNFIXABLE	3	Pixel marked as unfixable in ap3d
BADDARK	4	Pixel marked as bad as determined from dark frame
BADFLAT	5	Pixel marked as bad as determined from flat frame
BADERR	6	Pixel set to have very high error (not used)
NOSKY	7	No sky available for this pixel from sky fibers
LITTROW_GHOST	8	Pixel falls in Littrow ghost, may be affected
PERSIST_HIGH	9	Pixel falls in high persistence region, may be affected
PERSIST_MED	10	Pixel falls in medium persistence region, may be affected
PERSIST_LOW	11	Pixel falls in low persistence region, may be affected
SIG_SKYLINE	12	Pixel falls near sky line that has significant flux compared with object
SIG_TELLURIC	13	Pixel falls near telluric line that has significant absorption
NOT_ENOUGH_PSF	14	Less than 50 percent PSF in good pixels
	15

APOGEE_STARFLAG: APOGEE star level bitmask

Bit Name	Binary Digit	Description
BAD_PIXELS	0	Spectrum has many bad pixels (>40%): BAD
COMMISSIONING	1	Commissioning data (MJD<55761), non-standard configuration, poor LSF: WARN
BRIGHT_NEIGHBOR	2	Star has neighbor more than 10 times brighter: WARN
VERY_BRIGHT_NEIGHBOR	3	Star has neighbor more than 100 times brighter: BAD
LOW_SNR	4	Spectrum has low S/N (S/N<5): BAD
	5
	6
	7
	8
PERSIST_HIGH	9	Spectrum has significant number (>20%) of pixels in high persistence region: WARN
PERSIST_MED	10	Spectrum has significant number (>20%) of pixels in medium persistence region: WARN
PERSIST_LOW	11	Spectrum has significant number (>20%) of pixels in low persistence region: WARN
PERSIST_JUMP_POS	12	Spectrum show obvious positive jump in blue chip: WARN
PERSIST_JUMP_NEG	13	Spectrum show obvious negative jump in blue chip: WARN
	14
	15
SUSPECT_RV_COMBINATION	16	WARNING: RVs from synthetic template differ significantly from those from combined template
SUSPECT_BROAD_LINES	17	WARNING: cross-correlation peak with template significantly broader than autocorrelation of template
	18
	19
	20
	21
	22
	23
	24
	25
	26
	27
	28
	29
	30
	31

APOGEE_RV_FLAG: APOGEE RV level bitmask

Bit Name	Binary Digit	Description
BAD_PIXELS	0	Spectrum has many bad pixels (>40%): BAD
COMMISSIONING	1	Commissioning data (MJD<55761), non-standard configuration, poor LSF: WARN
BRIGHT_NEIGHBOR	2	Star has neighbor more than 10 times brighter: WARN
VERY_BRIGHT_NEIGHBOR	3	Star has neighbor more than 100 times brighter: BAD
LOW_SNR	4	Spectrum has low S/N (S/N<5): BAD
	5
	6
	7
	8
PERSIST_HIGH	9	Spectrum has significant number (>20%) of pixels in high persistence region: WARN
PERSIST_MED	10	Spectrum has significant number (>20%) of pixels in medium persistence region: WARN
PERSIST_LOW	11	Spectrum has significant number (>20%) of pixels in low persistence region: WARN
PERSIST_JUMP_POS	12	Spectrum show obvious positive jump in blue chip: WARN
PERSIST_JUMP_NEG	13	Spectrum show obvious negative jump in blue chip: WARN
	14
	15
SUSPECT_RV_COMBINATION	16	WARNING: RVs from synthetic template differ significantly from those from combined template
SUSPECT_BROAD_LINES	17	WARNING: cross-correlation peak with template significantly broader than autocorrelation of template
	18
	19
	20
	21
	22
	23
	24
	25
	26
	27
	28
	29
	30
	31

APOGEE_ASPCAPFLAG: APOGEE ASPCAP bitmask

Bit Name	Binary Digit	Description
TEFF_WARN	0	WARNING on effective temperature (see PARAMFLAG[0] for details)
LOGG_WARN	1	WARNING on log g (see PARAMFLAG[1] for details)
VMICRO_WARN	2	WARNING on vmicro (see PARAMFLAG[2] for details)
METALS_WARN	3	WARNING on metals (see PARAMFLAG[3] for details)
ALPHAFE_WARN	4	WARNING on [alpha/Fe] (see PARAMFLAG[4] for details)
CFE_WARN	5	WARNING on [C/Fe] (see PARAMFLAG[5] for details)
NFE_WARN	6	WARNING on [N/Fe] (see PARAMFLAG[6] for details)
STAR_WARN	7	WARNING overall for star: set if any of TEFF, LOGG, CHI2, COLORTE, ROTATION, SN warn are set
CHI2_WARN	8	high chi^2 (> 2*median at ASPCAP temperature (WARN)
COLORTE_WARN	9	effective temperature more than 500K from photometric temperature for dereddened color (WARN)
ROTATION_WARN	10	Spectrum has broad lines, with possible bad effects: FWHM of cross-correlation of spectrum with best RV template relative to auto-correltion of template > 1.5 (WARN)
SN_WARN	11	S/N<70 (WARN)
	12
	13
VSINI_WARN	14
	15
TEFF_BAD	16	BAD effective temperature (see PARAMFLAG[0] for details)
LOGG_BAD	17	BAD log g (see PARAMFLAG[1] for details)
VMICRO_BAD	18	BAD vmicro (see PARAMFLAG[2] for details)
METALS_BAD	19	BAD metals (see PARAMFLAG[3] for details)
ALPHAFE_BAD	20	BAD [alpha/Fe] (see PARAMFLAG[4] for details)
CFE_BAD	21	BAD [C/Fe] (see PARAMFLAG[5] for details)
NFE_BAD	22	BAD [N/Fe] (see PARAMFLAG[6] for details)
STAR_BAD	23	BAD overall for star: set if any of TEFF, LOGG, CHI2, COLORTE, ROTATION, SN error are set, or any parameter is near grid edge (GRIDEDGE_BAD is set in any PARAMFLAG)
CHI2_BAD	24	high chi^2 (> 5*median at ASPCAP temperature (BAD)
COLORTE_BAD	25	effective temperature more than 1000K from photometric temperature for dereddened color (BAD)
ROTATION_BAD	26	Spectrum has broad lines, with possible bad effects: FWHM of cross-correlation of spectrum with best RV template relative to auto-correltion of template > 2 (BAD)
SN_BAD	27	S/N<50 (BAD)
	28
	29
VSINI_BAD	30
NO_ASPCAP_RESULT	31

APOGEE_MEMBER: APOGEE membership bitmask

Bit Name	Binary Digit	Description
BAD_PIXELS	0	Spectrum has many bad pixels (>40%): BAD
COMMISSIONING	1	Commissioning data (MJD<55761), non-standard configuration, poor LSF: WARN
BRIGHT_NEIGHBOR	2	Star has neighbor more than 10 times brighter: WARN
VERY_BRIGHT_NEIGHBOR	3	Star has neighbor more than 100 times brighter: BAD
LOW_SNR	4	Spectrum has low S/N (S/N<5): BAD
	5
	6
	7
	8
PERSIST_HIGH	9	Spectrum has significant number (>20%) of pixels in high persistence region: WARN
PERSIST_MED	10	Spectrum has significant number (>20%) of pixels in medium persistence region: WARN
PERSIST_LOW	11	Spectrum has significant number (>20%) of pixels in low persistence region: WARN
PERSIST_JUMP_POS	12	Spectrum show obvious positive jump in blue chip: WARN
PERSIST_JUMP_NEG	13	Spectrum show obvious negative jump in blue chip: WARN
	14
	15
SUSPECT_RV_COMBINATION	16	WARNING: RVs from synthetic template differ significantly from those from combined template
SUSPECT_BROAD_LINES	17	WARNING: cross-correlation peak with template significantly broader than autocorrelation of template
	18
	19
	20
	21
	22
	23
	24
	25
	26
	27
	28
	29
	30
	31

APOGEE_PARAMFLAG/APOGEE_ELEMFLAG: APOGEE parameter/element bitmask flag

Bit Name	Binary Digit	Description
GRIDEDGE_BAD	0	Parameter within 1/8 grid spacing of grid edge
CALRANGE_BAD	1	Parameter outside valid range of calibration determination
OTHER_BAD	2	Other error condition
FERRE_BAD	3	FERRE failed to return a value
PARAM_MISMATCH_BAD	4	Elemental abundance from window differs > 0.5 dex from parameter abundance
	5-7	Currently unused
GRIDEDGE_WARN	8	Parameter within 1/2 grid spacing of grid edge
CALRANGE_WARN	9	Parameter in possibly unreliable range of calibration determination
OTHER_WARN	10	Other warning condition
FERRE_WARN	11	FERRE provided a value and a warning
PARAM_MISMATCH_WARN	12	Elemental abundance from window differs > 0.25 dex from parameter abundance
	13-15	Currently unused
PARAM_FIXED	16	Parameter set at fixed value, not fit
	17-31	Currently unused

MANGA_TARGET1: MaNGA galaxy targeting bits

The MANGA_TARGET1, MANGA_TARGET2, and MANGA_TARGET3 integers are used to track the target type (e.g., primary sample galaxies, F-standard stars, etc). Loosely speaking, all galaxy targets have a non-zero bit set for MANGA_TARGET1, all non-galaxy targets (e.g., MaStar) have a non-zero bit set for MANGA_TARGET2, and all ancillary program targets have a non-zero bit set for MANGA_TARGET3.

Bit name	Bit number	Decimal value	Description
NONE	0	1	Unused.
PRIMARY_PLUS_COM	1	2	March 2014 commissioning
SECONDARY_COM	2	4	March 2014 commissioning
COLOR_ENHANCED_COM	3	8	March 2014 commissioning
PRIMARY_v1_1_0	4	16	First tag, August 2014 plates
SECONDARY_v1_1_0	5	32	First tag, August 2014 plates
COLOR_ENHANCED_v1_1_0	6	64	First tag, August 2014 plates
PRIMARY_COM2	7	128	July 2014 commissioning
SECONDARY_COM2	8	256	July 2014 commissioning
COLOR_ENHANCED_COM2	9	512	July 2014 commissioning
PRIMARY_v1_2_0	10	1024	MaNGA main survey primary selection
SECONDARY_v1_2_0	11	2048	MaNGA main survey secondary selection
COLOR_ENHANCED_v1_2_0	12	4096	MaNGA main survey color-enhanced selection
FILLER	13	8192	Filler targets
RETIRED	14	16384	Retired bit; do not use

MANGA_TARGET2: MaNGA non-galaxy targeting bits

Bit name	Bit number	Decimal value	Description
NONE	0	1	Unused.
SKY	1	2
MaStar stellar library targets:
STELLIB_SDSS_COM	2	4	Commissioning selection using SDSS photometry.
STELLIB_2MASS_COM	3	8	Commissioning selection using 2MASS photometry.
STELLIB_KNOWN_COM	4	16	Commissioning selection of known parameter stars.
STELLIB_COM_mar2015	5	32	Commissioning selection in March 2015.
STELLIB_COM_jun2015	6	64	Commissioning selection in June 2015.
STELLIB_PS1	7	128	Library stars using PS1 photometry.
STELLIB_APASS	8	256	Library stars using APASS photometry.
STELLIB_PHOTO_COM	9	512	Commissioning selection using photo-derived para.
STELLIB_aug2015	10	1024	Global Selection generated in Aug 2015.
STELLIB_SDSS	11	2048	Library stars using SDSS photometry.
STELLIB_GAIA	12	4096	Library stars using GAIA photometry, g band only.
STELLIB_TYCHO2	13	8192	Library stars using TYCHO2 photometry (B and V in place of u and r).
STELLIB_BRIGHT	14	16384	Bright stars observed with short exposures.
STELLIB_UNRELIABLE	15	32768	Library stars with unreliable photometry
STELLIB_GAIADR2	16	65536	Library stars using Gaia DR2 photometry, G, BP, RP
Spectrophotometric calibration standards:
STD_FSTAR_COM	20	1048576
STD_WD_COM	21	2097152
STD_STD_COM	22	4194304
STD_FSTAR	23	8388608
STD_WD	24	16777216
STD_APASS_COM	25	33554432	Commissioning selection of stds using APASS photometry
STD_PS1_COM	26	67108864	Commissioning selection of stds using PS1 photometry
STD_BRIGHT	27	134217728	standards on bright star plates
PSF	28	268435456	PSF calibration test objects

MANGA_TARGET3: MaNGA ancillary targeting bits

Bit name	Bit number	Decimal value	Description
NONE	0	1	Unused.
AGN_BAT	1	2
AGN_OIII	2	4
AGN_WISE	3	8
AGN_PALOMAR	4	16
VOID	5	32
EDGE_ON_WINDS	6	64
PAIR_ENLARGE	7	128
PAIR_RECENTER	8	256
PAIR_SIM	9	512
PAIR_2IFU	10	1024
LETTERS	11	2048
MASSIVE	12	4096
MWA	13	8192
DWARF	14	16384
RADIO_JETS	15	32768
DISKMASS	16	65536
BCG	17	131072
ANGST	18	262144
DEEP_COMA	19	524288
IC342	20	1048576
M31	21	2097152
SN_ENV	22	4194304
MW_ANALOG	23	8388608
POST-STARBURST	24	16777216
GLSB	25	33554432
SN1A_HOST	26	67108864
GLOBULAR_CLUSTER	27	134217728

MANGA_DRP2PIXMASK: 2d DRP per-pixel mask

The 2d section of the MaNGA/MaStar DRP (i.e., reducing a single exposure of an entire plate through to the flux calibrated stage) uses the MANGA_DRP2PIXMASK maskbits. These maskbits apply to individual pixels in these images, and are used to determine (e.g.) where the extraction quality is bad due to hot pixels, cosmic ray hits, etc. These masks are contained in the MASK extensions to data produced by the 2d DRP.

Bit name	Bit number	Decimal value	Description
The following mask bits are for fibers:
NOPLUG	0	1	Fiber not listed in plugmap file.
BADTRACE	1	2	Bad trace.
BADFLAT	2	4	Low counts in fiberflat.
BADARC	3	8	Bad arc solution.
MANYBADCOLUMNS	4	16	More than 10% of pixels are bad columns.
MANYREJECTED	5	32	More than 10% of pixels are rejected in extraction.
LARGESHIFT	6	64	Large spatial shift between flat and object position.
BADSKYFIBER	7	128	Sky fiber shows extreme residuals.
NEARWHOPPER	8	256	Within 2 fibers of a whopping fiber (exclusive).
WHOPPER	9	512	Whopping fiber, with a very bright source.
SMEARIMAGE	10	1024	Smear available for red and blue cameras.
SMEARHIGHSN	11	2048	S/N sufficient for full smear fit.
SMEARMEDSN	12	4096	S/N only sufficient for scaled median fit.
DEADFIBER	13	8192	Broken fiber according to metrology files.
The following mask bits are for a pixel:
SATURATION	14	16384	Pixel considered saturated.
BADPIX	15	32768	Pixel flagged in badpix reference file.
COSMIC	16	65536	Pixel flagged as cosmic ray.
NEARBADPIXEL	17	131072	Bad pixel within 3 pixels of trace.
LOWFLAT	18	262144	Flat field less than 0.5.
FULLREJECT	19	524288	Pixel fully rejected in extraction model fit (INVVAR=0).
PARTIALREJECT	20	1048576	Some pixels rejected in extraction model fit.
SCATTEREDLIGHT	21	2097152	Scattered light significant.
CROSSTALK	22	4194304	Cross-talk significant.
NOSKY	23	8388608	Sky level unknown at this wavelength (INVVAR=0).
BRIGHTSKY	24	16777216	Sky level > flux + 10(flux_err) AND sky > 1.25 median(sky,99 pixels).
NODATA	25	33554432	No data available in combine B-spline (INVVAR=0).
COMBINEREJ	26	671108864	Rejected in combine B-spline.
BADFLUXFACTOR	27	134217728	Low flux-calibration or flux-correction factor.
BADSKYCHI	28	268435456	Relative chi2 > 3 in sky residuals at this wavelength.
REDMONSTER	29	536870912	Contiguous region of bad chi2 in sky residuals (with threshhold of relative chi2 > 3).
3DREJECT	30	1073741824	Used in RSS file, indicates should be rejected when making 3D cube.

MANGA_DRP3PIXMASK: 3d DRP per-pixel mask

Since the RSS files combining all exposures for specific IFUs have the same data format as the 2d pipeline, they retain the MANGA_DRP2PIXMASK mask bits. These are informative, in the sense that they tell the end user why a given pixel was masked at the detector level (e.g., cosmic ray, full rejection of the model fit during spectral extraction, etc.).
The combined 3d data cubes use the MANGA_DRP3PIXMASK mask bits that describe whether a given spaxel should be used for science analyses. For instance, it tells where dead fibers are, low relative exposure depth (e.g. at the edges of the frame), no coverage (beyond the borders of the IFU hexagon but within the rectilinear data cube frame, etc. The most generally useful mask bit though is the ‘DONOTUSE’ bit, which should be self explanatory, and is a distillation of all of the relevant reasons why not to trust particular values.
There is also a FORESTAR bit that indicates where a foreground star has been noted, and should probably be masked out for galaxy analyses. Since the spectra in these regions are still valid, having the FORESTAR bit set does not automatically set the DONOTUSE bit.

Bit name	Bit number	Decimal value	Description
NOCOV	0	1	No coverage in cube.
LOWCOV	1	2	Low coverage depth in cube.
DEADFIBER	2	4	Major contributing fiber is dead.
FORESTAR	3	8	Foreground star.
DONOTUSE	10	1024	Do not use this spaxel for science.

MANGA_DAPPIXMASK: Mask for 2d DAP derived maps

MANGA_DAPPIXMASK is the 2d image bitmap used to describe the quality of individual pixel measurements in the DAP MAPS file. In addition to reproducing some entries from the MANGA_DRP3PIXMASK for the data cubes (e.g., flagging foreground stars, low coverage, etc) it also adds some new entries indicating spaxels for which the fitting algorithms failed in some manner (e.g., by reaching the bounds of allowable values, failing to derive a fit, etc). The most important flags are incorporated into the DONOTUSE bit, which indicates that a given pixel should not be used for science.

The NEARBOUND flag is used to signify that a returned parameter is likely biased by an imposed boundary on the allowed parameter space. These are specifically relevant to the kinematics (both for stars and ionized-gas) from pPXF. pPXF imposes a ±2000 km/s limit relative to the input guess velocity (set to cz as given by the SCINPVEL header keyword and most often identical to the NSA redshift) on the returned velocity and dv/100 < σ < 1000 limit on the velocity dispersion, where dv is the size of the MaNGA LOGCUBE wavelength channel (~70 km/s; given by VSTEP header keyword). The returned velocity is determined to be NEARBOUND if the “best-fit” value is within 100th of the width of the allowed range of either boundary; i.e., NEARBOUND is triggered if the velocity is -2000 < v < -1980 or 1980 < v < 2000. For the velocity dispersion, NEARBOUND is triggered by the same criterion but geometrically; i.e., if the velocity dispersion is 0.69 < σ < 0.74 or 929.8 < σ < 1000.

The UNRELIABLE flag is not incorporated into the DONOTUSE flag. This flag is intended to act as a warning to users that the data may be biased in some way, based on a set of criteria developed by the data pipeline team. You are strongly encouraged to understand the implications of this flag on the data and how to properly make the distinction between the DONOTUSE and UNRELIABLE flags for your science application. For DR15, the UNRELIABLE flag is only set if there are masked pixels in any of the wavelength passbands used when calculating the emission-line equivalent widths or the spectral indices (extensions EMLINE_SEW, EMLINE_GEW, and SPECINDEX in the MAPS file).

Bit name	Bit number	Decimal value	Description
NOCOV	0	1	No coverage in cube.
LOWCOV	1	2	Low coverage depth in cube.
DEADFIBER	2	4	Major contributing fiber is dead.
FORESTAR	3	8	Foreground star.
NOVALUE	4	16	Spaxel was not fit because it did not meet selection criteria.
UNRELIABLE	5	32	Value is deemed unreliable.
MATHERROR	6	64	Mathematical error in computing value.
FITFAILED	7	128	Attempted fit for property failed.
NEARBOUND	8	256	Fitted value is too near an imposed boundary.
NOCORRECTION	9	512	Appropriate correction not available.
MULTICOMP	10	1024	Multi-component velocity features present (placeholder, not used in DR15).
DONOTUSE	30	1073741824	Do not use this spaxel for science.

MANGA_DAPSPECMASK: Mask bits for MANGA DAP model data cubes

MANGA_DAPSPECMASK is the 3d cube bitmap used to describe the quality of individual spaxel fits in the DAP model data cube file.

Bit name	Bit number	Decimal value	Description
IGNORED	0	1	Ignored because of DRP flags or stacking parameters.
FORESTAR	1	2	There is a foreground star within the data cube.
FLUXINVALID	2	4	Ignored because (stacked) flux not valid.
IVARINVALID	3	8	Ignored because inverse variance not valid.
ARTIFACT	4	16	Contains a designated artifact.
FITIGNORED	5	32	Ignored during fit.
FITFAILED	6	64	Fit failed in this region.
ELIGNORED	7	128	Ignored during emission-line fit.
ELFAILED	8	256	Emission-line fit failed.
NOMODEL	9	512	Identifies pixels outside of the fitted spectral range.

MANGA_DRP2QUAL: 2d DRP reduction quality

The quality of DRP-2d products is tracked using the integer DRP2QUAL that is contained in the output FITS headers of all 2d DRP products (and in the OBSINFO extensions of all 3d DRP products). This uses the bitmask values MANGA_DRP2QUAL. These provide information to the pipeline about failure points that need to be addressed in quality control. For instance, a detected failure in sky subtraction will trigger a mask bit SKYSUBBAD to be set; the flux calibration routine will detect this, and not try to flux calibrate data that has failed the sky subtraction stage.

Bit name	Bit number	Decimal value	Description
RETIRED	0	1	Retired bit; do not use.
EXTRACTBAD	1	2	Many bad values in extracted frame.
EXTRACTBRIGHT	2	4	Extracted spectra abnormally bright.
LOWEXPTIME	3	8	Exposure time less than 10 minutes.
BADIFU	4	16	One or more IFUs missing/bad in this frame.
HIGHSCAT	5	32	High scattered light levels.
SCATFAIL	6	64	Failure to correct high scattered light levels.
BADDITHER	7	128	Bad dither location information.
ARCFOCUS	8	256	Bad focus on arc frames.
RAMPAGINGBUNNY	9	512	Rampaging dust bunnies in IFU flats.
SKYSUBBAD	10	1024	Bad sky subtraction.
SKYSUBFAIL	11	2048	Failed sky subtraction.
FULLCLOUD	12	4096	Completely cloudy exposure.
BADFLEXURE	13	8192	Abnormally high flexure LSF correction.
VGROOVEFAIL	14	16384	Possible V-groove glue failure.
NOGUIDER	15	32768	No guider data available.
NOSPEC1	16	65536	No data from spec1.
NOSPEC2	17	131072	No data from spec2.
BLOWTORCH	18	262144	Blowtorch artifact detected.
RETIRED2	19	524288	Bit retired from use.
SEVEREBT	20	1048576	Severe blowtorch artifact.

MANGA_DRP3QUAL: 3d DRP reduction quality

The quality of DRP-3d products is tracked using the integer DRP3QUAL that is contained in the output FITS headers of all 3d DRP products. This uses the bitmask values MANGA_DRP3QUAL. These provide information to end-users and the DAP about final cubes and RSS files that do not meet quality standards (e.g., this ifu dropped out of the plate for some observations, so the data are not as deep as for other IFUs on the plate).

Bit name	Bit number	Decimal value	Description
RETIRED	0	1	Bit retired from use; do not use.
BADDEPTH	1	2	IFU does not reach target depth.
SKYSUBBAD	2	4	Bad sky subtraction in one or more frames.
HIGHSCAT	3	8	High scattered light in one or more frames.
BADASTROM	4	16	Bad astrometry in one or more frames.
VARIABLELSF	5	32	LSF varies signif. between component spectra.
BADOMEGA	6	64	Omega greater than threshhold in one or more sets.
BADSET	7	128	One or more sets are bad.
BADFLUX	8	256	Bad flux calibration.
BADPSF	9	512	PSF estimate may be bad.
MANYDEAD	10	1024	Many dead fibers.
RETIRED2	11	2048	Bit retired, moved into MASTAR_QUAL instead.
BLOWTORCH	12	4096	Blowtorch artifact detected in one or more frames.
SEVEREBT	13	8192	Severe blowtorch artifact.
UNUSUAL	14	16384	Cube slightly unusual in some way but good for most science.
CRITICAL	30	1073741824	Critical failure in one or more frames .

MANGA_DAPQUAL: Mask bits for MaNGA DAP quality flags

The overall quality of DAP data products is tracked using MANGA_DAPQUAL bit contained in the headers of the DAP output fits files. This bit provides information to end-users about DAP maps and model data cubes that do not meet quality standards (e.g., a bad NSA redshift, ppxf failures, etc.). Anything with the CRITICAL bit set in MANGA_DAPQUAL should generally not be used for scientific purposes.

Bit name	Bit number	Decimal value	Description
FORESTAR	0	1	There is a foreground star within the data cube.
BADZ	1	2	NSA redshift does not match derived redshift.
LINELESS	2	4	No emission lines in data cube.
PPXFFAIL	3	8	PPXF fails to fit this object.
SINGLEBIN	4	16	Voronoi binning resulted in all spectra in a single bin.
BADGEOM	5	32	Invalid input geometry; elliptical coordinates and effective radius are meaningless.
DRPCRIT	28	268435456	Critical failure in DRP.
DAPCRIT	29	536870912	Critical failure in DAP.
CRITICAL	30	1073741824	Critical failure in DRP or DAP.

MASTAR_QUAL: Mask bits for MaStar spectra quality flags

The overall quality of summary MaStar spectra is tracked using the integers MJDQUAL, EXPQUAL, and MSTRQUAL that are contained in the output FITS headers and/or binary tables of all MaStar data products. These all use the bitmask values MASTAR_QUAL (see further info at MaStar spectra). These provide information to end-users about spectra that do not meet quality standards (e.g., bad flux calibration, high variance in radial velocity estimates, problematic visual inspection, etc.).

Bit name	Bit number	Decimal value	Description
NODATA	0	1	No Data.
SKYSUBBAD	1	2	Bad sky subtraction in one or more frames.
HIGHSCAT	2	4	High scattered light in one or more frames.
BADFLUX	3	8	Bad flux calibration.
LOWCOV	4	16	PSF-covering fraction by fiber is too small (<10%).
POORCAL	5	32	Poor throughput.
BADHELIORV	6	64	High variance between stellar RVs.
MANUAL	7	128	Flagged as problematic by visual inspection.
EMLINE	8	256	Spectrum contain emission lines.
LOWSN	9	512	Per-MJD Spectrum has median S/N <= 15.
MULTIFIBER	10	1024	Composite spectrum combined from multiple fibers.
BLOWTORCH	11	2048	Blowtorch artifact in one or more frames.
SEVEREBT	12	4096	Severe blowtorch artifact.
UPTURNRISK	13	8192	Risk of having a red-upturn.
REDUPTURN	14	16384	Red-upturn identified by visual inspection.
REDDOWNTURN	15	32768	Red-downturn identified by visual inspection.
NONSTELLAR	16	65536	Non-stellar spectrum based on visual inspection.
CRITICAL	30	1073741824	Critical failure in one or more frames.