AstroSat/SXT observation of the outburst of SAX J1747.0-2853
ATel #15368; N. T. Thomas, S. Apala, S. Lavanya, E. Elsa, S. B. Gudennavar (CHRIST - Deemed to be University), R. Misra (IUCAA), S. G. Bubbly (CHRIST - Deemed to be University)
on 7 May 2022; 05:58 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Shivappa Gudennavar (shivappa.b.gudennavar@christuniversity.in )
Subjects: X-ray, Binary, Neutron Star, Transient
SAX J1747.0-2853 is a neutron star low mass X-ray binary (NS-LMXB), located at the galactic bulge (inât Zand et al. 1998, IAUC, 6846). Since its discovery, it has undergone outbursts in the years 2004 (ATel #255), 2005 (ATels #637, #642), 2006 (ATels #734, #892), 2007 (ATels #1228, #1233), 2009 (ATels #1944, #1951), 2011 (ATel #3217), 2016 (ATel #9115) and 2019 (ATels #12576, #12580). On 24th April, 2022, MAXI/GSC detected an X-ray outburst from the direction of the source (ATel #15346).
Further, Swift confirmed the outburst to be from SAX J1747.0-2853 (ATel #15347) on 25th April, 2022.
We report the AstroSat observation of SAX J1747.0-2853 with the SXT instrument. The source was observed for ~22 ks by SXT between 30th April, 2022, 08:21:15 UTC and 01st May, 2022, 08:14:28 UTC at RA(J2000): 17h 47m 02.4s and Dec(J2000): -28d 52m 59.0s. The spectrum of the source in the energy range 0.3 - 7.0 keV could be adequately fit using the model combination tbabs*bbody having blackbody temperature (kT) of 1.18 +/- 0.01 keV and absorption column density (NH) of (5.55 +0.08/-0.13) x 1022 cm-2. The unabsorbed blackbody flux in the 0.3 to 7.0 keV range was calculated to be (2.58 +0.03/-0.05) x 10-9 erg/cm2/sec.
Follow up multiwavelength observations of SAX J1747.0-2853 are encouraged.
Acknowledgement: We thank the AstroSat operations team for scheduling this ToO observation and the SXT POC for the timely release of data.
