THE SPIN OF THE BLACK HOLE 4U 1543-47

Abstract

We present a new analysis of Rossi X-ray Timing Explorer observations of the\n2002 outburst of the transient X-ray nova 4U 1543-47. We focus on observations\nin the High/Soft state, and attempt to measure the spin of the black hole by\nsimultaneously fitting the thermal disk continuum and by modeling the broadened\niron k-shell emission lines and additional blurred reflection features.\nPrevious works have found that use of these methods individually returns\ncontradictory values for the dimensionless spin parameter a* =cJ/GM^2. We find\nthat when used in conjunction with each other, a moderate spin is obtained\n(a*=0.43 +0.22 -0.31) that is actually consistent with both other values within\nerrors. We discuss limitations of our analysis, systematic uncertainties, and\nimplications of this measurement, and compare our result to those previously\nclaimed for 4U 1543-47.\n