Targeting Overview
MWM is targeting OB stars using their high luminosities and blue intrinsic colors. The main sample selection is done in the spirit of the SDSS-V requirement of a known and well-defined selection function, and is therefore based on Gaia DR2 photometry and astrometry combined with the 2MASS photometric information. First, all objects whose absolute magnitude in the K photometric band is smaller than -0.61 are selected, which roughly corresponds to a B3 main-sequence star. Ultimately, several color cuts are applied to clean the sample from intrinsically bright red giant- and asymptotic giant-branch stars, as well as from objects with unnaturally blue colors. The target selection and its rationale is described more fully in Zari et al. (2021). In addition, a few thousand Cepheids from the catalog of Inno et al. (2021).
Cartons
OB Star Cartons in Targeting Generation v0.5.3
The OB cartons for target generation v0.5.3 use magnitudes from the 2MASS Point Source Catalog and Gaia DR2 and parallaxes (in mas) and rule from Gaia DR2.
- mwm_ob_core
- parallax < 10((10-K-0.61)/5)
- G < 16
- J-K-0.25(G-K) < 0.10
- J-K-0.25(G-K)> -0.30
- J-H<0.15(G-K)+0.05
- J-H > 0.15(G-K)-0.15
- J-K < 0.23(G-K)+0.03
- G > 2(G-K)+3.0
- Cross-match separation between Gaia DR2 and 2MASS < 1″
- ruwe < 1.4
- mwm_ob_cepheids
- In Inno et al. (2021) catalog
Cadences
All OB star program cartons take the bright_3x1 cadence.