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Last modified: 12 April 2024


Chandra Source Catalog Release 2.0 (CSC 2.0)

Preliminary CSC 2.1 Production Current Database Crossmatches and SDSS Spectra[New]

The CSC 2.1 production current database on 14 November 2022 (389k sources) has been cross-matched to four catalogs: Gaia DR3, Legacy Survey DR10, PanSTARRS-1, and 2MASS, finding counterparts for 229k CSC 2.1 production current database sources. Cross-matching this table with SDSS DR17 spectroscopy yields more than 17k objects with SDSS spectra, including pipeline classifications and radial velocities. Details and links to the results may be found at the CSC 2 Crossmatches page.

Caveat: Incorrect Master Source Positions

An issue has recently been identified where incorrect master source positions and associated position error ellipses were determined for a very small set of compact sources in the CSC 2.0. Please see the Caveats and Limitations page for further information and a list of affected master sources. These positions and error ellipses are corrected in CSC 2.1.

The Chandra Source Catalog (CSC) is the definitive catalog of X-ray sources detected by the Chandra X-ray Observatory. Version 2.0 (CSC2) is the second major release of the catalog; the current minor release is version 2.0.1, updated on 2020 November 24 (for more information see the Catalog Version History). CSC 2.0 represents a significant improvement with respect to version 1.1 in terms of sky coverage, sensitivity and capabilities. CSC2 includes measured properties for 317,167 unique compact and extended X-ray sources in the sky, allowing statistical analysis of large samples, as well as individual source studies. Extracted properties are provided for 928,280 individual observation detections identified in 10,382 Chandra ACIS and HRC-I imaging observations released publicly through the end of 2014. CSC 2.0 also includes—as an "alpha" release—photometric properties for 1,299 highly extended (≳30″) sources, together with surface brightness polygons for several contour levels. There are approximately 1,700 columns of tabular data with pertinent information about each source across 5 bands (broad, hard, medium, soft, and ultra-soft) for ACIS and 1 band (wide) for HRC (see the energy-bands page for the definition of these bands), and 40 data products per source. The total size of the archive is close to 36 TB.

[The detections are distributed across the sky, with various features, such as the galactic plane and Magellanic clouds, visible]

[Version: full-size]

The locations, in Galactic coordinates, of the CSC 2.0 detections. The size of each symbol is proportional to the logarithm of the number of sources detected in the stack, while the color encodes the number of closely-located observations.