SIXSRVYCAT ivo://nasa.heasarc/sixsrvycat NASA/GSFC HEASARC Bottacini et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The supermassive black holes at the center of active galactic nuclei (AGNs) are surrounded by obscuring matter that can block nuclear radiation. Depending on the amount of blocked radiation, the flux from the AGN can be too faint to be detected by currently operating hard X-ray (above 15 keV) missions. At these energies, only ~1% of the intensity of the cosmic X-ray background (CXB) can be resolved into point-like sources that are AGNs. In this work, the authors address the question of undetected sources contributing to the CXB with a very sensitive and new hard X-ray survey: the Swift-INTEGRAL X-ray (SIX) survey, which is obtained with the new approach of combining the Swift/BAT and INTEGRAL/IBIS X-ray observations. The authors merge the observations of both missions, which enhances the exposure time and reduces systematic uncertainties. As a result, they obtain a new survey over a wide sky area of 6200 deg<sup>2</sup> covering the region of the North Ecliptic Pole (NEP) and extending to the contiguous Coma region that is more sensitive than the surveys of Swift/BAT or INTEGRAL/IBIS alone. Their sample comprises 113 sources having S/N ratios of above 4.8 sigma: 86 AGNs (Seyfert-like and blazars), 5 galaxies, 2 clusters of galaxies, 3 Galactic sources, 3 previously detected unidentified X-ray sources, and 14 unidentified sources. The scientific outcome from the study of the sample has been properly addressed to study the evolution of AGNs at a redshift below 0.4. The authors do not find any evolution using the 1/V<sub>max</sub> method. Their sample of faint sources is a suitable target for the new generation of hard X-ray telescopes with focusing techniques. This table was created by the HEASARC in August 2012 based on an electronic version of Table 2 from the reference paper which was obtained from the ApJS web site. This is a service provided by NASA HEASARC . 2012ApJS..201...34B https://heasarc.gsfc.nasa.gov/W3Browse/all/sixsrvycat.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=sixsrvycat& GET text/xml 180 99999 true 203.6978 -23.425 0.166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=sixsrvycat GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_sixsrvycat&Action=More+Options&Action=Parameter+Search&ConeAdd=1 SWIFT 0.166666666666667 X-ray public sixsrvycat Swift-INTEGRAL X-Ray (SIX) Survey Catalog name Object Designation 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 redshift Redshift src.redshift double nullable flux X-Ray Flux erg/cm^2/s phot.flux;em.X-ray.hard double nullable snr Signal-to-Noise Ratio stat.snr double nullable log_lx Logarithm of the X-Ray Luminosity log(erg/s) phys.luminosity;em.X-ray.hard double nullable broad_type Broad Object Classification src.class char nullable subtype Subclassification of Object Type src.class char nullable bii Galactic Latitude degree pos.galactic.lat double nullable refcode Reference Code for Object meta.ref;src short nullable class Browse Object Classification src.class short nullable log_nh Logarithm of the Column Density log(cm^-2) phys.columnDensity double nullable lii Galactic Longitude degree pos.galactic.lon 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