CSCSTOBAS - Chandra Source Catalog Stacked Source-Observation Source Associations, v2.2

Overview

The Chandra Source Catalog Stacked Source-Observation Source Associations, v2.2 is an associated table related to the Chandra Source Catalog (CSC). By combining Chandra's sub-arcsecond on-axis spatial resolution and low instrumental background with consistent data processing, the CSC delivers a wide variety of uniformly calibrated properties and science ready data products for detected sources over four decades of flux.

The Stacked Observation Detections Table (CSCSTACK) includes 527,230 detections (and 960,929 detections and photometric upper limits) based on 11,317 X-ray observations stacks. The Per-Observation Detections Table (CSCSTACKOB) records the properties extracted separately from each observation included in the observation stack for each stacked-observation detection for 1,433,096 individual detections (2,536,232 upper limits) within 17,879 observations.

This table maps the stacked observation detections table (CSCSTACK) records to their associated per-observation data (CSCSTACKOB).

Catalog Bibcode

2024ApJS..274...22E

References

Chandra Source Catalog Release 2 (CSC Release 2 Series).
    Evans I.N., Evans J.D., Martinez-Galarza J.R., Miller J.B., Primini F.A.,
    Azadi M., Burke D.J,. Civano F.M,. D'Abrusco R., Fabbiano G.,
    Graessle D.E., Grier J.D., Houck J.C., Lauer J., McCollough M.L.,
    Nowak M.A., Plummer D.A., Rots A.H., Siemiginowska A., Tibbetts M.S.
   <Astrophys. J. Suppl. Ser.,, 274, 22 (2024)>
   =2024ApJS..274...22E
   =2024yCat.9070....0E

Provenance

This database table was last updated by the HEASARC in November 2026 and is based on a download of the online version of the "Stack Source/Observation Source Associations" table, version 2.2, at the CXC using the CLI. Refer to https://cxc.harvard.edu/csc/cli/ for details.

Links to Related CSC Tables

Chandra Source Catalog, v2.2 (CSC): The master sources table includes measured properties for 432,713 unique compact and extended X-ray sources in the sky. By combining Chandra's sub-arcsecond on-axis spatial resolution and low instrumental background with consistent data processing, the CSC delivers a wide variety of uniformly calibrated properties and science ready data products for detected sources over four decades of flux.

Chandra Source Catalog Master Source-Stacked Source Associations, v2.2 (CSCASSOC) maps the master sources table CSC records to their associated stacked observation detections in CSCSTACK, and it also identifies the type of linkage (unique, ambiguous, or non-detection) that associates the two.

Chandra Source Catalog Stacked Observation Detections, v2.2 (CSCSTACK) includes 527,230 detections (960,929 total entries consisting of detections plus photometric upper limits) based on 11,317 stacks of X-ray observations. Exploiting the unique resolution and very low background of Chandra data, the limiting sensitivity of the catalog is enhanced significantly by stacking (co-adding) multiple observations of the same field prior to source detection.

Chandra Source Catalog Stacked Source Per-Observation Detections, v2.2 (CSCSTACKOB) includes 1,433,096 detections (and 2,536,232 detections and upper limits) from 17,879 observations. Extracted properties are provided for these individual observation detections identified in Chandra ACIS and HRC-I imaging observations released publicly through the end of 2024.

For more details about the catalog organization, please refer to the CXC page.

Parameters

Detect_Stack_ID
The detection stack identifier (designation of observation stack used for source detection) in the format '{acis|hrc}fJhhmmsss{p|m}ddmmss_nnn' where Jhhmmss{p|m}ddmmss is the J2000 coordinates in sexagesimal units with hh, mm, ss providing hours, minutes and seconds for the RA component and p/m gives the '+/-' along with the dd, mm, ss for the decimal degrees for the Declination component. The nnn designates the catalog version id and may be '001' or '002' for the stacks. Stacks that end in '_002' are ones that have extra observations compared to CSC 2.0, whereas a stack that ends in '_001' either was in CSC 2.0 and has now new data, or was not in CSC 2.0. (CXC: stack_observation_assoc.detect_stack_id)

ObsID
The observation identifier. (CXC: stack_observation_assoc.obsid)

Obs_Interval
The observation interval number. (CXC: stack_observation_assoc.obi)

Region_ID
The detection region identifier (component number). (CXC: stack_observation_assoc.region_id)

Contact Person

Questions regarding the CSCSTOBAS database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Thursday, 05-Nov-2026 17:39:23 EST