SRG/eROSITA upper limit on X-ray flux from Gaia BH3
ATel #16591; M. Gilfanov (IKI, MPA), R. Sunyaev (IKI, MPA), I. Bikmaev (KFU), P. Medvedev (IKI)
on 16 Apr 2024; 20:45 UT
Credential Certification: Marat Gilfanov (gilfanov@iki.rssi.ru)
Subjects: X-ray, Black Hole
Referred to by ATel #: 16832
SRG/eROSITA scanned the region of the sky containing Gaia BH3 - the most massive stellar black hole in the Milky Way recently discovered by Gaia (Panuzzo et al., 2024), on four occasions during the active phase of its all-sky survey in 2020-2022. No X-ray source was detected at its position with the upper limit of 1.2e-14 erg/s/cm2 at the 3 sigma confidence, 0.3-2.3 keV, no absorption correction applied. Assuming the source distance of 590 pc this corresponds to the upper limit on the luminosity of 5e29 erg/s, of the order of ~1e-10 Ledd for a 33 Msun black hole.
