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Description
This table contains the Chamaeleon (Cha) I North Cloud Chandra X-Ray point source catalog. Sensitive X-ray imaging surveys provide a new and effective tool to establish the census of pre-main-sequence (PMS) stars in nearby young stellar clusters. A deep Chandra X-Ray Observatory (CXO) observation of PMS stars in the Chamaeleon I North cloud achieved a limiting total-band X-ray luminosity of log L<sub>t</sub> ~ 10<sup>27</sup> ergs/s (0.5 - 8 keV band) in a 0.8 x 0.8 pc<sup>2</sup> region. Of the 107 X-ray sources, 37 are associated with Galactic stars, of which 27 are previously recognized cloud members. These include 3 PMS brown dwarfs: the protostellar brown dwarf ISO 192 has a particularly high level of magnetic activity. Follow-up optical photometry and spectroscopy establish that 9-10 of the Chandra sources are probably magnetically active background stars. No new X-ray-discovered stars were confidently found despite the high sensitivity of the Chandra observation. From these findings, the authors argue that the sample of 27 PMS cloud members in the Chandra field is uncontaminated and complete down to K = 12 or a stellar mass of about 0.1 solar masses. A 16'x 16' region of the Cha I North cloud was observed with the imaging array of the Advanced CCD Imaging Spectrometer (ACIS-I) detector on board the Chandra X-Ray Observatory. The observation took place on 2001 July 2.25-3.04 UT with the detector aimpoint set at 11 10 00.0, -76 35 00 (J2000.0 RA and Declination). The effective exposure was 66.3 ksec. The authors also obtained VI-band CCD images of most of the ACIS field with the 1m telescope and CCD detector at the South African Astronomical Observatory (SAAO) during 2002 February. This table was created by the HEASARC in February 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/614/267">CDS catalog J/ApJ/614/267</a> files table1.dat, table2.dat and table3.dat. This is a service provided by NASA HEASARC .
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