Tutorials

Welcome to the SDSS tutorial section. This section contains a series of hands-on tutorials to learn how to work with different aspects of the SDSS data. If you are unsure what kind of SDSS data or which SDSS survey is best for your science, then go the the mapper overview page: this page contains short descriptions with links for more details on all SDSS surveys (on-going and completed).

ON THIS PAGE
Running tutorials on SciServer
Education focused tutorials
MWM Centered Tutorials
BHM Centered Tutorials
LVM Tutorial
Survey Wide Tutorials
SQL
Tutorials for previous data releases

Updates for DR20

To accompany the release of LVM data, a number of LVM tutorials are now available. There are also new tutorials for both MWM and BHM, and new tutorials for Value Added Catalogs. All tutorials also now use sdss-access as the standard method for downloading SDSS data.

All SDSS tutorials are available on the SDSS GitHub page and for interactive use on SciServer Compute.

Running Tutorials on SciServer

A specific image is available for working with SDSS data. In order to access both SDSS data and the suite of software tools you will need, create an account then when you create a new container follow these steps:

  • Choose the SDSS_DR20 or SDSS_DR19 Compute image, depending on which data release you want to work with. These images contain the sdss_access python package, as well as astropy, astroquery, specutils and other useful libraries.
  • We recommend you select the “Kraken” domain when creating your container. If you plan to use newer tools such as tensorflow (for example if running the machine learning tutorial), you must use this domain.
  • Include the SDSS SAS DR19 or SDSS SAS DR20 data volume depending on which image you selected. It is important to choose the DR consistently for sdss_access to work correctly. It will be mounted in the Jupyter session under  /home/idies/workspace/sdss_sas_DRXX/.
  • Once in a notebook, make sure the py312 python kernel is selected.

Education Focused Tutorials

SDSS strives to make accessible resources for educators. For the release of SDSS DR19, two tutorials have been created. A MWM focused tutorial guides students through the Galaxy using stars observed with the infrared APOGEE spectrographs, while a BHM focused tutorial introduces students to optical spectra of super-massive blackholes. Both tutorials included suggested exercises, and links to solutions are provided.

MWM Centered Tutorials

The MWM survey is focused on stars in the Milky Way. For many science cases, the most useful SDSS outputs are summary files containing stellar parameters for each star in the data release.

New for DR20

A new tutorial trains a machine learning model (using tensorflow) with an allStar summary and catalog of ages to predict ages for the full ASPCAP dataset. A new tutorial exploring ASPCAP model spectra and comparing them to the observed spectrum is also available.

Updated tutorials

There is an MDwarf tutorial using the astraAllStarMDwarfType summary file to plot an HR diagram of M dwarfs observed in DR19 and using the astraAllVisitBossNet summary file to compare results between the two pipelines.

There is a tutorial showing the Galactic chemical trends using the astraAllStarASPCAP summary file. Relationships between [Fe/H] and Galactic position, as well as [Fe/H] vs [Mg/Fe] and Galactic position, are shown.

A final tutorial uses the astraAllStarASPCAP summary file to plot an HR diagram of all DR19 APOGEE stars using photometry and astrometry from Gaia DR3.

For anyone who wants to use SDSS spectra directly, there is a notebook that retrieves and plots an APOGEE spectrum and another that showcases a BOSS white dwarf spectrum.

BHM Centered Tutorials

The BHM survey targets quasars and galaxies. The BOSS pipeline coadds spectra, assuming they are taken within some reasonable time frame, and outputs useful parameters such as an estimated redshift for each object.

A tutorial exploring spectra coadds clearly shows how coadding two spectra decreases the noise, and plots the included model spectrum.

Another tutorial provides an alternative model of a BOSS spectrum.

Value Added Catalog Tutorials

if this section is going to exist John needs to create it a day or two before DR day, since VAC tutorials are being withheld till then.

LVM Tutorials

The LVM survey is taking optical integral-field spectra of the Milky Way, the Magellanic Clouds, and a number of nearby Local Volume galaxies. A number of tutorials have been added for LVM data. Tutorials include creating tile mosaics, interacting with LVM SFrame products, using the DRP/DAP all summary files and the provided bitmasks, a look at the process of creating models provided by the LVM Data Analysis Pipeline (DAP), and finally a recreation of the plots provided in Sanchez et al. 2025.

Survey Wide Tutorials

MWM and BHM have worked closely together to obtain, process, and release the DR20 spectra. Many important survey components are therefore shared between mappers.

New to SDSS-V DR20:

  • Multi Object Spectrograph (MOS) target files, summarizing the targeting strategy for SDSS V, have been provided for every SDSS V data release. Tutorials demonstrating usage for both fits and parquet versions of these files are now available.

Updated for SDSS-V DR20:

  • sdss_id is now the primary identifier for SDSS objects. A tutorial showing how to cross-match using this ID is available.
  • Previous iterations of SDSS often used bit-masks to encode targeting information. SDSS V provides a new tool call semaphore to help users navigate targeting information; a semaphore tutorial is provided.
  • In order to target brighter targets, significant effort was made to carefully offset targets in order to reduce the flux entering a given fiber. A tutorial highlighting the success of this program is available.
  • The Allspec data product summarizes every spectrum observed by SDSS. A tutorial providing an example of how to use the allspec table, such as matching columns to data reduction pipeline summary files, has been created.

SQL

More information on querying SDSS data via a SQL database can be found on the SQL Examples page. There are also several examples of SQL searches available on the SkyServer SQL Search page or SkyServer Sample Queries page.

Tutorials for previous data releases

If you want to work with data that was released in SDSS I-IV, then check the Completed Surveys page for direct links to data descriptions, caveats, and relevant tutorials. Completed surveys include:

We have tutorials available on parameter files, fits files, and using bitmasks, and a page with conversions between our wavelength and magnitude systems and other systems. You can find an overview page of prior tutorials here. This page lists tutorials especially relevant to previous SDSS data r

 

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