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Last modified: 14 April 2021


Status and Version History

Current Schedule

Designation Date Description and Notes
CSC 2.0.1 2020-11-24

Release 2.0.1 of the Chandra Source Catalog updates intra-observation and inter-observation variability properties to resolve two issues detected in release 2.0. These issues resulted in an underestimation of the variability probabilities in release 2.0 for some CSC sources at the Stacked Observation Detection and Master Source levels. Additionally, an error that caused incorrect calculations of the inter-observation variability properties when one or more per-observation detections included upper limits for the fluxes, and/or lower or upper limits for the hardness ratios, was fixed.

Users who have been using the "current release" to access the 2.0.1 catalog should review the caveats and limitations page to see what changes may have been made to the final release.

CSC 2.0 2019-10-24

The second major release of the Chandra Source Catalog (CSC release 2.0) includes data for 317,167 unique sources, and 928,280 per-observation detections of ACIS and HRC public imaging observations through the end of 2014. There are approximately 1700 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 CSCview application is the primary interface to the column and data products provided for CSC 2.0. New to CSC 2.0 is the Quick-Search Web inferface.

CSC 2.0 pre1 2017-11-15

This has been superseded by the CSC 2.0.1 release.

This pre-release adds source designations - that is, location and error; an estimate of the average aperture photometry; and the detections that form each source - to the CSC 2.0 pd2 release. The list contains 315,875 sources, formed from 374,349 detections (16 detections from the pd2 release have been rejected).

Note that this pre-release does not include the full characterisation for each source, such as the full set of aperture photometry measurements or spectral properties, nor does it include information on large, extended X-ray sources (the "convex hull" detections).

CSC 2.0 pd2 2017-09-18

This has been superseded by the CSC 2.0.1 release.

Final detections from all 7,287 of the observation stacks in CSC 2.0. The release contains 374,365 positions, likelihoods, extents, a fitted intensity that is a reasonably good proxy for aperture photometry, along with associated errors for these quantities. The CSC 2.0 pd2 data access page provides access to the table as well as a full list of the properties and caveats.

This release extends the pd1 release to all observations that are included in CSC release 2.0, as well as fixing several issues with the pd1 release, as described in the caveats section. It also includes information on the observations used to create each stack, and images showing the approximate sky coverage of each stack.

CSC 2.0 pd1 2017-03-21

This has been superseded by the CSC 2.0.1 release.

CSC 2.0 pd0 2015-08-03

This has been superseded by the CSC 2.0.1 release.

Development History

Chandra Newsletter articles on the status of the Chandra Source Catalog.