ChaMP Extended Stellar Survey (ChESS) X-Ray Catalog Virtual Observatory Resource

Authors
  1. Covey et al.
  2. Published by
    NASA/GSFC HEASARC
Abstract
      The ChaMP Extended Stellar Survey (ChESS) X-ray catalog contains 348 X-ray-emitting stars identified from correlating the Extended Chandra Multiwavelength Project (ChaMP), a wide-area serendipitous survey based on archival X-ray images, with the Sloan Digital Sky Survey (SDSS). The authors used morphological star/galaxy separation, matching to an SDSS quasar catalog, an optical color-magnitude cut, and X-ray data-quality tests to create this catalog, from a sample of 2121 matched ChaMP/SDSS sources. Their cuts retain 92% of the spectroscopically confirmed stars in the original sample while excluding 99.6% of the 684 spectroscopically confirmed extragalactic sources. Fewer than 3% of the sources in their final catalog are previously identified stellar X-ray emitters. For 42 catalog members, spectroscopic classifications are available in the literature. New spectral classifications and H-alpha measurements are presented for an additional 79 stars. The catalog is dominated by main-sequence stars; the authors estimate the fraction of giants in ChESS to be ~10%. They identify seven giant stars (including a possible Cepheid and an RR Lyrae star) as ChaMP sources, as well as three cataclysmic variables. They derive distances from ~10 to 2000 pc for the stars in the catalog using photometric parallax relations appropriate for dwarfs on the main sequence and calculate their X-ray and bolometric luminosities. These stars lie in a unique space in the L<sub>X</sub>-distance plane, filling the gap between the nearby stars identified as counterparts to sources in the ROSAT All Sky Survey and the more distant stars detected in deep Chandra and XMM-Newton surveys. For 36 newly identified X-ray-emitting M stars, the authors calculated L<sub>H-alpha</sub>/L<sub>bol</sub>. The quantities L<sub>H-alpha</sub>/L<sub>bol</sub> and L<sub>X</sub>/L<sub>bol</sub> are linearly related below L<sub>X</sub>/L<sub>bol</sub> ~ 3 x 10<sup>-4</sup>, while L<sub>H-alpha</sub>/L<sub>bol</sub> appears to turn over at larger L<sub>X</sub>/L<sub>bol</sub> values. Stars with reliable SDSS photometry have an ~0.1 mag blue excess in u-g, likely due to increased chromospheric continuum emission. Photometric metallicity estimates suggest that the sample is evenly split between the young and old disk populations of the Galaxy; the lowest activity sources belong to the old disk population, a clear signature of the decay of magnetic activity with age. This table was created by the HEASARC in January 2009 based on the electronic version of Tables 2 and 3 from the reference paper which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .
    
Keywords
  1. Survey Source
Bibliographic source
2008ApJS..178..339C
See also HTML
https://heasarc.gsfc.nasa.gov/W3Browse/all/chesscat.html
IVOA Identifier IVOID
ivo://nasa.heasarc/chesscat

Access

IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=chesscat&
IVOA Table Access TAP
https://heasarc.gsfc.nasa.gov/xamin/vo/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
Web browser access HTML
https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_chesscat&Action=More+Options&Action=Parameter+Search&ConeAdd=1

History

2025-09-05T00:00:00
Resource record created
2025-09-05

Contact

Name
NASA/GSFC HEASARC help desk
E-Mail
heasarc-vo at athena.gsfc.nasa.gov