Swift/BAT sees MAXI J1535-571 declining in 15-50 keV
ATel #10733; D. M. Palmer (LANL) and H. A. Krimm (NSF/USRA) on behalf of the Swift/BAT team
on 11 Sep 2017; 17:31 UT
Credential Certification: David M. Palmer (palmer@lanl.gov)
Subjects: X-ray, Gamma Ray, Black Hole, Neutron Star, Transient
BAT monitoring of MAXI J1535-571 shows that, in the 15-50 keV band, the source reached a peak around 2017 Sept 9 and has since begun to decline. At peak, the BAT count rate was 0.43 +/- 0.015 ct s-1 cm-2, or approximately twice the mean flux of the Crab. It is currently ~15% below its peak intensity.
This is consistent with reports (ATEL #10729, Nakahira et al; ATEL #10731, Kennea) that the source is brightening below 10 keV and softening its spectrum, indicating a hard-to-soft transition.
BAT lightcurves for this source (Krimm et al., 2013, ApJSS 209,14) are available at
https://swift.gsfc.nasa.gov/results/transients/weak/MAXIJ1535-571/