Data Release 15

DR15 Highlights

The SDSS telescope at night
Image Credit: Patrick Gaulme

Data Release 15 (DR15) is the third data release of the fourth phase of the Sloan Digital Sky Survey (SDSS-IV). DR15 contains SDSS observations through July 2017.

DR15 includes the following:

New data cubes from integral field unit (IFU) spectroscopic observations of nearby galaxies from the SDSS component Mapping Nearby Galaxies at APO (MaNGA), as well as the first data products and maps from the MaNGA Data Analysis Pipeline (DAP)
The first optical stellar spectra of the MaNGA Stellar Library program (MaStar)
Marvin: a new tool to visualise and analyse MaNGA datacubes and maps
The most current spectra from the SDSS components extended Baryon Oscillation Spectroscopic Survey (eBOSS) and Apache Point Observatory Galaxy Evolution Experiment 2 (APOGEE-2), as well as newly improved documentation of APOGEE-2 data
Value Added Catalogs (VACs) for all three SDSS components (eBOSS, APOGEE-2 and MaNGA), including targeting catalogs
The most current reprocessed imaging and spectra from the SDSS legacy survey

DR15 directly follows DR14. As always, SDSS data releases are cumulative, so DR15 includes all the sky coverage of prior releases. Data Release 12, Data Release 13, and Data Release 14 are still available on this website, and prior data releases are available from www.sdss3.org (for DR8 through DR10) or classic.sdss.org (for DR1 through DR7).

Working with SDSS Data

If you use public SDSS data in your paper, please see our guide on how to cite the SDSS. We hope you find our resources useful!

If you have questions about working with SDSS data, please email our helpdesk.

Accessing the Data

Data Release 15 includes six types of data: images, optical spectra (SDSS/SEGUE/BOSS/SEQUELS/eBOSS), infrared spectra (APOGEE/APOGEE-2), IFU spectra (MaNGA), stellar library spectra (MaStar), and catalog data (parameters measured from images and spectra, such as magnitudes and redshifts).

The SDSS offers several different online data access tools, each suited to a particular need:

Website: Purpose
DR15 Science Archive Server: Interactive spectra and image mosaics
Marvin: Visualisation and analysis tool for MaNGA data cubes and maps
DR15 SkyServer: Browser-based access to the Catalog Archive Server (CAS) database, with resources for learning SQL and projects to teach science
CasJobs: Flexible advanced SQL-based interface to the CAS, for all data releases (quick registration required). To select data from DR15, choose DR15 as the query context.
DR15 FITS: Direct download access to DR15 FITS data files for experts
Data Model: Details of the Science Archive Server (SAS) directory structure, file formats, and the contents of each file

Past Data Releases

Note that the current best reduction of all previously released data is available within DR15.

About Data Release 15

The links below give more information about various aspects of DR15. Most of these links are also available from the second-level menubar at the top of each page in the DR15 section of this site.

What's new?: Explains the differences between DR15 and previous data releases.
Scope: Describes what data are available in DR15, including sky coverage, data size, and resolution information.
Datasets: Shows how to get common types of SDSS data, and provides links to all SDSS data access tools. This is the best place to look for a quick start using SDSS data.
Imaging: Explains what imaging data DR15 contains. It also provides details on the SDSS imaging pipeline, the calibration process, and what quantities (including units) are available in imaging catalog data.
Optical Spectra: Explains what data are available from the SDSS's two optical spectrographs (SDSS-I and BOSS), and provides details on associated data, including target flags, redshifts, and classifications.
APOGEE Spectra: Explains what data are available from the SDSS's APOGEE infrared spectrograph, and provides details on associated data including information on the spectra, targets, radial velocities, and determinations of stellar atmospheric parameters.
MaNGA Spectra: Describes the available data and methods from the new component survey Mapping Nearby Galaxies at APO (MaNGA), which uses integral-field spectroscopy to learn about the dynamics and compositions of nearby galaxies.
MaStar Library: Explains the available data from the MaNGA Stellar Library (MaStar), which uses the MaNGA fibre bundles in bright time to observe stars.
MARVELS Spectra: Describes the data and methods of the MARVELS component survey, which searched for extrasolar planets around nearby stars.
Value Added Catalogs: Gives an overview of all the Value Added Catalogs (VACs) available in DR15.
Algorithms: Lists the principal SDSS data processing algorithms, including target selection, and contains complete details on how the algorithms work. It also includes software for working with SDSS data.
Help: Contains a glossary, Frequently Asked Questions, and other resources to help you get started in using DR15.
Tutorials: Provide step-by-step guides to common research and teaching tasks using SDSS data. This is a good place to look for guidance in doing your science with the SDSS.