SRG/ART-XC detection of the ongoing activity from historical X-ray source AX J1538.3-5541
ATel #15251; I. Mereminskiy, A. Semena, A. Lutovinov, S. Molkov, A. Tkachenko, I. Lapshov (IKI RAS)
on 1 Mar 2022; 07:26 UT
Credential Certification: Ilya Mereminskiy (i.a.mereminskiy@gmail.com)
Subjects: X-ray, Black Hole, Neutron Star, Transient
On Feb.26-27, 2022, during the fifth on-going all-sky survey the Mikhail Pavlinsky ART-XC telescope detected the bright X-ray source located 13 arcsec off the position of AX J1538.3-5541.
Given the typical ART-XC localization accuracy (90% error radius is 15 arcsec) and brightness
of the source (about (2±0.4)x10-11 erg/cm2/s in the 4-12 keV energy band) we believe that we are observing a new activity from this poorly studied source, that was proposed to be a candidate absorbed LMXB by Degenaar et al (2012).
Despite a precise localization of the source by Chandra, no obvious optical candidate is
known. However, a weak (mKs = 18±0.5) low-significance NIR source was
detected in follow-up NIR observations with the Magellan Baade telescope by Anderson
et al. (2014).
We encourage rapid multiwavelength, especially optical/NIR and radio observations of
this poorly studied source to investigate its nature.
ART-XC is the X-ray telescope on board the SRG observatory which was
launched from the Baikonur cosmodrome on 13 July 2019 by the Proton rocket. ART-XC has
been renamed 'Mikhail Pavlinsky ART-XC telescope' in honor of its first PI, Dr.
Mikhail Pavlinsky.
References:
Degenaar et al., 2012, 2012A&A...540A..22D
Anderson et al., 2014, 2014ApJS..212...13A
