Data Access for SDSS DR15 Overview

This page explains how to access DR15 data, and provides links to various data access tools.

The SDSS web sites offer several different online data access tools, each suited to a particular need. These sites are described in more detail in the Available Tools page.

The information on this page is organized by type of data. Each section includes a table that describes a common task you might perform with that type of data, along with a link to the best tool for that task.

If your question isn't addressed here, please look at the Frequently Asked Questions and/or Tutorials help pages.

If you are having difficulty connecting to any data server, please check the status page for announcements about planned outages.

What is in DR15?

Data Release 15 includes these types of data:

Optical spectra of galaxies, stars and quasars from the SDSS extended Baryon Oscillation Spectroscopic Survey (eBOSS) and prior optical spectroscopic programs.
Infrared spectra from the SDSS Apache Point Observatory Galaxy Evolution Experiment (APOGEE and APOGEE-2), including stellar abundance estimates for additional elements from the ASPCAP pipeline and The Cannon
Data cubes and maps from integral field unit (IFU) spectroscopic observations of nearby galaxies from the SDSS Mapping Nearby Galaxies at APO (MaNGA) survey
The first spectra of the MaNGA Stellar Library program (MaStar)
Legacy imaging from prior SDSS programs
A large selection of Value Added Catalogs (VACS) from current and previous surveys

How to find...

Images

The SDSS has taken deep images of more than one-third of the entire night sky. You can view SDSS images online for any object or sky position in the survey area, and download images of SDSS fields as FITS files.

I need to...: Tool to use
browse through sky images: Navigate
create a telescope finding chart: Finding chart
search-view-download SDSS imaging fields: Imaging Field Search
generate SDSS imaging mosaics: Imaging Mosaics
get a list of thumbnails: Image List

Since some stars were targeted for APOGEE infrared spectroscopy using 2MASS survey data, we also offer access to 2MASS images through the Navigate tool (click on the 2MASS button).

Data from the SDSS-II Supernova Survey is not available in DR8-15, but is available in its entirety at the SDSS-II Supernova Survey website.

Optical Spectra

Data Release 14 marked the first release of eBOSS spectra, and included all optical spectra from the original SDSS-I/-II, SEGUE, and BOSS, as well as additional optical spectra measured as part of the Sloan Extended Quasar, ELG, and LRG Survey (SEQUELS) program. These spectra are all included into DR15.

I need to...: Tool to use
know whether SDSS has measured an optical spectrum for my object: Navigate
explore the optical spectra platelist: Optical Plate Search
search-download FITS files with the optical spectrum for my object(s):: Optical Spectrum Search
view the optical spectrum for my object(s):: Optical Spectrum View
get 50,000 spectra: Bulk download documentation
know which optical spectroscopic data files are available: Spectroscopic pipeline description
understand the format of a specific data file: Data Model

APOGEE and APOGEE-2 Spectra

Data Release 14 marked the first release of APOGEE-2 spectra, and included all APOGEE infrared spectra measured so far, reprocessed with additional element abundances. The new element abundances brings the total number of species to 23: C, CI, N, O, Na, Mg, Al, Si, P, S, K, Ca, Ti, TiII, V, Cr, Mn, Fe, Co, Ni, Cu, Ge, and Rb. All this data is also included into DR15, and in addition new documentation describing these data products in more detail has been added.

I need to...: Tool to use
know whether the SDSS has measured an infrared spectrum for my object: Navigate
explore the infrared spectra platelist: Infrared Plate Search
search-download FITS files with the infrared spectrum for my object(s): Infrared Spectrum Search
view the infrared visits for my object(s): Infrared Spectrum View Visits
view the infrared stars (combined or ASPCAP or Cannon spectra) for my object(s): Infrared Spectrum View Stars
get 50,000 infrared spectra: Bulk download documentation
know which APOGEE spectra data files are available: Spectroscopic pipeline description
get all measured parameters for all APOGEE stars at once: allStar and allVisit files

MaNGA Spectra

Data Release 15 is the third installment of the SDSS's Mapping Nearby Galaxies at APO (MaNGA) survey. DR15 includes summary data on MaNGA targets and raw data consisting of data cubes. It also includes for the first time analysed data products and maps, as well as a visualisation and analysis tool (Marvin).

I need to...: Tool to use
see summary data from SDSS IFU observations for my object: Explore: MaNGA
learn how to download data cubes or maps: MaNGA data access
download MaNGA data by plate: SAS data browser for MaNGA
visualise or analyse MaNGA data cubes or maps: Marvin
learn other ways to access MaNGA data: MaNGA tutorials

MaStar Stellar Library Spectra

Data Release 15 is first public dat release for MaNGA's stellar library program MaStar. DR15 includes summary data on MaStar targets as well as single and combined optical spectra for stars.

I need to...: Tool to use
see summary data from SDSS observations for my object: Explore: MaStar
learn how to download MaStar spectra: MaStar data access
view the optical spectrum for my objects: MaStar Spectrum View
learn other ways to access MaStar data: MaStar tutorials

MARVELS Spectra

DR15 includes all MARVELS Interferometry spectra.

I need to...: Tool to use
view and retrieve MARVELS data: MARVELS data

Catalog Data

Catalog data summarize quantities measured from the images and spectra such as magnitudes, redshifts, and object classifications. These are available either from the Catalog Archive Server (CAS) database, or as binary tables in FITS file format.

I need to...: Tool to use
find all objects which match some simple selection criteria: SkyServer SQL Search
learn how to write SQL queries: SQL Tutorial or SQL in SkyServer or Sample Queries
perform a complicated, CPU-intensive query of SDSS catalog data: CasJobs
generate my own database with custom tables of a subset of SDSS data: CasJobs
understand the CAS database schema:: Schema Browser
download fits files with the catalog data: See the bulk download documentation
understand the format of a specific catalog data file: Data Model

Data Access Sites

Website: Purpose
www.sdss4.org/dr15: DR15 Documentation (this site)
https://dr15.sdss.org: Science Archive Webapp: interactive search-view-download tool for infrared and optical spectra, imaging fields, and image mosaic creation.
https://dr15.sdss.org/marvin/: Marvin: interactive visualisation and analysis tool for MaNGA data cubes and maps.
https://data.sdss.org/sas/dr15: Direct download access to DR15 data files for experts
https://data.sdss.org/datamodel: Details of the SAS directory structure, file formats, and the contents of each file
https://skyserver.sdss.org/dr15: SkyServer: Browser-based access to the Catalog Archive Server (CAS) database, with resources for learning SQL and projects to teach science
https://skyserver.sdss.org/casjobs: Flexible advanced SQL-based interface to the CAS, for all data releases