Search For Rapid X-ray Variability from the Black-Hole Candidate GRO J1655-40

Abstract

We have examined fifteen days of CGRO/BATSE data, obtained during the first outburst of the black-hole candidate source GRO J1655-40, to search for rapid variability of its X-ray flux. We find no evidence for significant variability of GRO J1655-40 during our observations, with a 2 sigma upper limit to the fractional r.m.s. amplitude in the frequency range 0.03-0.488 Hz of 6.6%. We cannot, on the basis of our observations, determine the source state (low, high, or very-high state) of GRO J1655-40.

15 pages, 4 Postscript figures, uses aasms4.sty. Accepted for publication in Astrophysical Journal Letters