SRG/ART-XC Galactic Bulge deep survey. II. Catalogue of point sources
Sunyaev, R.; Krivonos, R.; Sazonov, S.; Vikhlinin, A.; Lutovinov, A.; Molkov, S.; Semena, N.; Tkachenko, A.; Lapshov, I.; Burenin, R.; Mereminskiy, I.; Semena, A.; Pavlinsky, M.; Levin, V.; Arefiev, V.; Buntov, M.; Garanin, S.; Garin, M.; Grigorovich, S.; Shtykovsky, A.; Voron, V.; Borisov, K.; Karasev, D.
Russia, United States
Abstract
We present a catalogue of point sources detected with the Mikhail Pavlinsky ART-XC telescope onboard the SRG observatory during a wide-field survey of the Galactic Bulge that was conducted as part of the mission's calibration and performance verification phase in 2019. The survey consisted of nearly 18 d of consecutive scanning observations of the sky region |l| < 6 deg, |b| < 2.5 deg with the median sensitivity of 4 × 10-13 erg s-1 cm-2 in the 4-12 keV energy band, which allows the detection of sources down to a luminosity of 3 × 1033 erg s-1 near the Galactic Centre. Using a maximum-likelihood-based algorithm, 172 sources were detected. Of these, 153 are registered on the average 4-12 keV map and 18 sources are either extremely hard (detected only at energies above 7 keV) or highly variable (detected only in individual scans shorter than a day). For 121 sources, there are plausible counterparts in other X-ray source catalogues, including 43 with known classification. The remaining 51 sources are previously unknown objects, discovered by ART-XC during the Galactic Bulge survey.