In addition to the primary SDSS photometry and spectroscopy, there are a few extra catalogs created by our collaborators that are distributed through the SAS. These Value-Added Catalogs (VACs) are listed below, and include catalogs that were released in earlier data releases.
Spectral Identification of eROSITA Sources DR20: Optical and X-ray properties
Spectral Identification of eROSITA Sources (SPIDERS): SDSS and eROSITA data of targets detected in X-rays by eROSITA and followed-up in the optical with SDSS.
Catalog Data
Abstract
This value added catalog provides data from SPIDERS (Spectral Identification of eROSITA Sources) targets in SDSS DR20, with X-ray data from eROSITA, optical data from SDSS, and some optical/infrared data of public photometric surveys. X-ray information is derived from the preliminary catalogues generated from the first three eROSITA All-Sky Surveys (eRASS1-3) in 2023. For each source that was observed in SDSS-V as a target from eROSITA, we provide: * From SDSS: Field, MJD, Catalog ID, Run2D, Target index, Object type, Target flag, Fiber position coordinates, Redshift (with error and warning), Median S/N, Class, Best fit stellar template and properties (spectral type, effective temperature, surface gravity) * From eROSITA: Unique X-ray source identifier, Flux in the full eROSITA band and error, MJD, Morphological classification, Source detection likelihood, X-ray position estimate and positional error The VAC consists of two files, with DL1_eROSITA_eRASS3 providing data for each co-add spectrum, and DL1_eROSITA_eRASS3_allepoch providing data for stacked spectra (multiple observations of the same object). A detailed description of this VAC is available in section 10.1.3 of the SDSS DR20 paper and on Merloni et al. (in prep). The data model of this VAC is DL1_spec_SDSSV_eROSITA. This VAC is similar to the one released in SDSS DR19, though now with ~30x more individual spectra and ~10x more stacked spectra. The DR19 VAC is deprecated, with its data already embedded in the DR20 version. We therefore recommend that you use the DR20 VAC, described above. If you do still need access to the DR19 version of this VAC, then it is still available on the SAS and its data model is DL1_spec_eROSITA_eRASS1.
Catalog last modified: 2026-07-30 12:10:01