2011ATel.3407....1C

As part of an ongoing Chandra program for precise localization of X-ray transients in low-mass X-ray binaries, we obtained a short Chandra/HRC-S observation of the black hole transient MAXI J1543-562 in outburst (ATEL #3330, #3341, #3355, #3362). Our observation was made on 2011 June 3, 20:58 TT with an exposure time of 1135 s.

The source was detected with a source intensity of 14.5(1) count/s. The best-fit X-ray source position is:

RA(J2000) = 15h 43m 17.336s

Dec(J2000) = -56d 24' 48.35"

with an uncertainty radius of 0.6 arcsec (90% confidence). Our position is consistent with the 1.8 arcsec (90% confidence) Swift X-ray error circle (ATEL #3331), lying 1.3 arcsec from its center. It is outside the ∼0.9 arcsec radius ATCA radio error box (ATEL #3364), lying 1.8 arcsec from its center; however, the confidence level of the ATCA position uncertainty was not specified. The Chandra position is also consistent with optical/IR candidate B identified by Rau et al. (ATEL #3365), lying 0.3 arcsec away; however, it is inconsistent with both candidate A (0.8 arcsec away; see also ATEL #3359, #3372) and candidate C (1.0 arcsec away).

Our HRC-S observation does not provide spectral information. However, assuming the soft-state disk blackbody spectrum measured by Swift on May 17 (ATEL #3362; kT=1.23 keV, N_H=2e22 cm^(-2)), our measured count rate corresponds to an absorbed flux of 1.8e-9 erg/cm^2/s (0.5-10 keV).