MAXI/GSC detection of an increased soft x-ray flux in the black hole transient MAXI J1543-564
ATel #8582; Jie Lin and Wenfei Yu (Shanghai Astronomical Observatory)
on 23 Jan 2016; 14:27 UT
Credential Certification: Wenfei Yu (wenfei@shao.ac.cn)
Subjects: X-ray, Binary, Black Hole, Transient
Referred to by ATel #: 8585
Between MJD 57401 and MJD 57408, the 2-10 keV X-ray flux of the black hole candidate MAXI J1543-564 measured with MAXI/GSC had increased from -2+/-3 mCrab to 30+/-5 mCrab. Late on the average flux of the black hole candidate in the period froM MJD 57408 to MJD 57409 remained at the level of 28+/-3 mCrab. However, the source has not been significantly detected in the hard band (10-20 keV) with MAXI and in the 15-50 keV band with Swift/BAT. So the source has probably started a new outburst. The hardness ratio, on the other hand, indicates that the source has left the hard spectral state and might have entered the soft spectral state.
We have compared the current data with those of the most recent outburst starting at MJD 55685 (ATEL #3330, 3331, 3341, 3355, 3362). At the same soft X-ray level the source was leaving the hard state and the BAT 15-50 keV flux was nearly 0.03 mCrab. It seems that the source had a spectral transition at a lower flux level during the current outburst. Further X-ray observations would confirm these properties. Multi-wavelength observations are encouraged.
