{"@type": "dcat:Dataset", "accessLevel": "public", "bureauCode": ["026:00"], "contactPoint": {"@type": "vcard:Contact", "fn": "HEASARC Help Desk", "hasEmail": "mailto:andrew.ptak@nasa.gov"}, "description": "This table contains the Chandra X-ray point source catalogs for 9 Hickson Compact Groups (HCGs, 37 galaxies) at distances of 34 to 89 Mpc. The authors perform detailed X-ray point source detection and photometry and interpret the point source population by means of simulated hardness ratios. They thus estimate X-ray luminosities (L<sub>X</sub>) for all sources, most of which are too weak for reliable spectral fitting. For all sources, they provide counts, count rates, power-law indices (Gamma), hardness ratios, and L<sub>X</sub>, in the full (0.5-8.0 keV), soft (0.5-2.0 keV) and hard (2-8 keV) bands. In their paper, the authors use optical emission-line ratios from the literature to re-classify 24 galaxies as star-forming, accreting onto a supermassive black hole (AGNs), transition objects, or low-ionization nuclear emission regions. Two-thirds of their galaxies have nuclear X-ray sources with Swift/UVOT counterparts. Two nuclei have full-band X-ray luminosities >= 10<sup>42</sup> erg s<sup>-1</sup>, are strong multi-wavelength AGNs, and follow the known alpha<sub>OX</sub> - nu L_nu(near-UV)_ correlation for strong AGNs. Otherwise, most nuclei are X-ray faint, consistent with either a low-luminosity AGN or a nuclear X-ray binary population, and fall into the 'non-AGN' locus in alpha<sub>OX</sub> - nu L_nu(near-UV)_ space, which also hosts other normal galaxies. Each group was observed at the aim point of the back-illuminated S3 CCD of Chandra's Advanced CCD Imaging Spectrometer (ACIS), with the exception of HCG 90, which was observed with the ACIS-I array. The details of the 9 Chandra observations analyzed herein are given in Table 1 of the reference paper. The full details of the X-ray analysis and point source detection procedures are given in Section 3 of the reference paper. This table was created by the HEASARC in June 2014 based on electronic versions of Tables 2 and 3 from the reference paper which were obtained from the ApJS web site. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .", "distribution": [{"@type": "dcat:Distribution", "downloadURL": "https://heasarc.gsfc.nasa.gov/W3Browse/all/selhcgcxo.html", "format": "HTML", "mediaType": "text/html"}, {"@type": "dcat:Distribution", "downloadURL": "https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=selhcgcxo&", "format": "BIN", "mediaType": "application/octet-stream"}], "identifier": "ivo://nasa.heasarc/selhcgcxo", "keyword": ["__"], "landingPage": "ivo://nasa.heasarc/selhcgcxo", "license": "https://www.usa.gov/government-works", "modified": "2026-08-17", "programCode": ["026:000"], "publisher": {"@type": "org:Organization", "name": "High Energy Astrophysics Science Archive Research Center"}, "theme": ["Astrophysics"], "title": "Selected Hickson Compact Groups Chandra X-Ray Point Source Catalog"}