SACSSESCAT ivo://nasa.heasarc/sacssescat NASA/GSFC HEASARC Dai et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The Swift Active galactic nucleus (AGN) and Cluster Survey (SACS) uses 125 deg<sup>2</sup> of Swift X-ray Telescope (XRT) serendipitous fields with variable depths surrounding gamma-ray bursts to provide a medium depth (4 x 10<sup>-15</sup> erg cm<sup>-2</sup> s<sup>-1</sup>) and medium area survey filling the gap between deep, narrow Chandra/XMM-Newton surveys and wide, shallow ROSAT surveys. In the reference paper, a catalog of 22,563 point sources and 442 extended sources, and the number counts of the AGN and galaxy cluster populations are presented. SACS provides excellent constraints on the AGN number counts at the bright end with negligible uncertainties due to cosmic variance, and these constraints are consistent with previous measurements. The authors use Wide-field Infrared Survey Explorer (WISE) mid-infrared(MIR) colors to classify the sources. For AGNs, they can roughly separate the point sources into MIR-red and MIR-blue AGNs, finding roughly equal numbers of each type in the soft X-ray band (0.5-2.0 keV), but fewer MIR-blue sources in the hard X-ray band (2-8 keV). The cluster number counts, with 5% uncertainties from cosmic variance, are also consistent with previous surveys but span a much larger continuous flux range. Deep optical or IR followup observations of this cluster sample will significantly increase the number of higher redshift (z > 0.5) X-ray-selected clusters. This HEASARC table contains the list of 442 Swift XRT extended sources which were detected in the soft X-ray band image (0.5-2 keV) and contained in Table 4 of the reference paper. The authors defined the extended source catalog as those sources with S/N >= 4 and a minimum net photon count of 20 that are more than 3 sigma from the mean size of point sources for both their off-axis angle and S/N. The authors consider these extended sources to be candidate clusters of galaxies. This table was created by the HEASARC in July 2015 based on an electronic version of Table 4 of the reference paper, the list of Swift XRT extended sources detected in the soft X-ray (0.5-2 keV) band, which was obtained from the ApJS web site. This is a service provided by NASA HEASARC . 2015ApJS..218....8D https://heasarc.gsfc.nasa.gov/W3Browse/all/sacssescat.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=sacssescat& GET text/xml 180 99999 true 237.7497 -78.5602 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=sacssescat GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_sacssescat&Action=More+Options&Action=Parameter+Search&ConeAdd=1 SWIFT 0.0166666666666667 X-ray public sacssescat Swift AGN & Cluster Survey (SACS) Soft-Band (0.5-2 keV) Extended name Source Identifier meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable count_rate The 0.5-2 keV Count Rate ct/s phot.count;em.X-ray.soft double nullable count_rate_error Uncertainty in the 0.5-2 keV Count Rate ct/s stat.error;phot.count;em.X-ray.soft double nullable flux The 0.5-2 keV Flux erg/s/cm^2 phot.flux;em.X-ray.soft double nullable core_size Core Size arcsec phys.angSize;src double nullable extent Extent arcsec phys.angSize;src double nullable exposure Exposure s time.duration;obs.exposure double nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable bck_count_rate Background Count Rate ct/s/arcmin^2 phot;instr.background;em.X-ray.soft double nullable grb_field GRB Field meta.id;obs.field char nullable lii Galactic Longitude degree pos.galactic.lon double nullable bii Galactic Latitude degree pos.galactic.lat double nullable off_axis Off-Axis Angle arcmin instr.offset double nullable