ACDS V10.0 - Thu May 02 04:26:53 CEST 2019

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Detailed Description of CXC/V2 :
Chandra Catalog Release View

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Note : this is the description file of the original catalog. This HTML page corresponds well to the original description, but some minor changes in the format may have been introduced in the FITS output files in order to allow for arithmetic operations on quantities such as coordinates and times. h:m:s and d:m:s units are normally converted into degrees, and YYYY-MM-DD into julian days.
Similarly, some slight changes may have been introduced in the units; the value given in the HTML files supersedes the value indicated in the ReadMe file for this catalogue.
O/3         Extract from CSC 2.0 current database view
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Extract from Chandra Source Catalog Release 2.0 (CSC 2.0) Current Database
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ADC_Keywords: X-ray sources, Cross identifications

Mission_Name: CHANDRA


Description:

The Chandra Source Catalog (CSC) is ultimately intended to be the definitive catalog of X-ray sources 
detected by the Chandra X-ray Observatory. To achieve that goal, the catalog will be released to the 
user community in a series of increments with increasing capability. The second major release of the 
CSC (release 2.0) includes data for roughly 315,000 X-ray sources on the sky extracted from 10,382 
Chandra ACIS and HRC-I imaging observations released publicly through the end of 2014. 

Users are kindly requested to acknowledge their use of the Chandra Source Catalog in any resulting 
publications. http://cxc.harvard.edu/csc2/cite.html

The version operating at Strasbourg Observatory/CDS uses the results of an ADQL query
http://cxc.harvard.edu/csc2/cli/index.html and only lists a subset of all columns available in the 
database view.

File Summary:


       FileName      Lrecl  Records   Explanations


×                   80        .   This file
× ReadMe           156        .   This file
× Catalog          156        .   Result



Byte-by-byte Description of file:  Catalog


   Bytes Format Units   Label     Explanations


   1- 20  A20   ---     Name      source name in the form "2CXO Jhhmmss.s{+|-}ddmmss"
  21- 28  D8.7  deg     ra        source position, ICRS right ascension
  29- 36  D8.7  deg     dec       source position, ICRS declination
  37- 44  D8.7  arcsec errellipser0  major radius of the 95% confidence level position error ellipse
  45- 52  D8.7  arcsec errellipser1  minor radius of the 95% confidence level position error ellipse
  53- 60  D8.7  arcsec errellipseang  position angle (referenced from local true north) of the major axis
  61- 68  F8.7  --- significance  highest flux significance across all stacked observations and science energy bands
      69  I1    ---    conf_flag  source confused ?
      70  I1    ---     ext_flag  source extended ?
      71  I1    --- satsrcflag  source saturated in all observations ?
  72- 79  E8.2 erg/s*cm2 fluxaperavg_b  aperture-corrected net fluxaveraged over all observations
  80- 87  E8.2 erg/s*cm2 fluxaperavglolimb  68% lower confidence limit of fluxaperavg
  88- 95  E8.2 erg/s*cm2 fluxaperavghilimb  68% upper confidence limit of fluxaperavg
  96-103  D8.7  ---     hard_hm   (2.0-7.0 keV) to (1.2-2.0 keV) hardness ratio
 104-111  D8.7  --- hardhmlolim  68% lower confidence limit of hard_hm
 112-119  D8.7  --- hardhmhilim  68% upper confidence limit of hard_hm
 120-127  D8.7  ---     hard_ms   (1.2-2.0 keV) to (0.5-1.2 keV) hardness ratio
 128-135  D8.7  --- hardmslolim  68% lower confidence limit of hard_ms
 136-143  D8.7  --- hardmshilim  68% upper confidence limit of hard_ms
 144-147  I4    ---     acis_num  total number of ACIS imaging observations contributing
 148-156  F9.1  ---    acis_time  total exposure time (seconds of good time)


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