Available Tools for Data Access

Catalog data are available through SkyServer (also known as the Catalog Archive Server, or CAS). SkyServer also offers interactive tools to browse through SDSS images with links to associated spectra and catalog data about the objects on the images.

DR16 SkyServer

Interactive query tools for CAS

SkyServer Imaging Query Form

Simple image query form interface

SkyServer Spectroscopic Query Form

Simple spectroscopic query form interface

SkyServer Cross-ID

Match list of RA/Dec or IDs to imaging or spectroscopic catalog

Image List

Generate JPGs for a large set of objects

SkyServer Navigate

Point-and-click interface to JPG image of SDSS sky

SciServer Compute

Retrieve and analyze SDSS data using Python code running online

CASJobs

CAS SQL advanced user interface (use DR16 context)

The advanced DR16 CasJobs database interface gives you 500 MB or more of personal database space to select, analyze, and cross-identify SDSS data.

While CAS is the primary interface to the catalog data, the Science Archive Server (SAS) is the primary interface to the original images and spectra. It provides tools to interactively view and download SDSS spectra, download images of SDSS fields, and generate mosaics of those fields.

In addition, SAS contains directory structures with the data in the original binary (FITS) and text file formats. To understand the directory structure and file formats, please see the imaging data, spectroscopic data, and infrared spectroscopy pages. To understand the way in which the SDSS organizes its data, see Understanding SDSS Imaging Data, Understanding SDSS Spectroscopic Data, Understanding SDSS Infrared Spectroscopy Data and Understanding SDSS Integral-Field Spectroscopic Data. Full details on the structure of all the data are in the detailed data model.

SAS Optical Spectra

Webapp to search-view-download optical spectra

SAS Infrared Spectra

Webapp to search-view-download infrared spectra

SAS Stellar Library Spectra

Webapp to search-view-download MaStar stellar library spectra

SAS Imaging Fields

Webapp to search-view-download SDSS field images

SAS Imaging Mosaic

Webapp to create larger-scale mosaic images

Marvin

Web and Analysis Tool to visualize and analyse MaNGA integral-field spectroscopic data

Imaging catalogs

Directories of full image catalog files
BOSS_PHOTOOBJ data model

Corrected frames

Directories of full corrected image frames
BOSS_PHOTOOBJ/frames data model

Datasweep catalogs

Directories of reduced "sweep" imaging catalog data files
PHOTO_SWEEP data model

Optical Spectroscopy

Directories of optical spectra and catalogs.
Documentation, Legacy SPECTRO_REDUX data model, and BOSS_SPECTRO_REDUX data model

Infrared Spectroscopy

Directories of APOGEE spectra and catalogs
Documentation and APOGEE_REDUX data model

Stellar Library Spectra

Directories of MaStar Stellar Library spectra
Documentation and MaStar data model

IFU Spectroscopy

Directories of MaNGA spectra and catalogs
Documentation and MANGA_SPECTRO_REDUX data model

Note that both CAS and SAS will give you exactly the same catalog data. Essentially all of the data input into CAS is included in some form in the SAS. However, there are some small changes in naming convention (for example, "resolve_status" in SAS flat files is referred to as "resolveStatus" in CAS).

Expert users may need direct access to the data files themselves instead of webpage or database views of it. For this purpose, we provide the ability to directly download the files from SAS as described on the Bulk Download page.