2005PASP..117.1236F

This paper includes two parts. The first presents the spectral energy distributions (SEDs) of 49 globular cluster (GC) X-ray sources in 13 BATC (Beijing-Arizona-Taiwan-Connecticut) intermediate-band filters from 3800 to 10000 Å, and identifies 8 previously unidentified X-ray sources in M31. Using X-ray data from Einstein observations from 1979 to 1980, ROSAT High Resolution Imager observations in 1990, Chandra High Resolution Channel and ACIS-I observations from 1999 to 2001, and the BATC optical survey from 1995 to 1999, we find 49 GC X-ray sources and 8 new X-ray sources in the BATC M31 field. By analyzing SEDs and FWHMs, we determine that 4 of the 8 X-ray sources may be GC candidates. The second part presents some statistical relationships between 62 GC X-ray sources, of which 58 are already known and 4 are identified in this paper. The distribution of M31's GC X-ray sources' V magnitudes is bimodal, with peaks at m_v=15.65 and 17.89, which is different from the distribution of GC candidates. The distribution of B-V color shows that the GC X-ray sources seem to be associated preferentially with the redder GCs, in agreement with previous results. Kolmogorov-Smirnov test shows that the maximum value of the absolute difference of B-V distributions of GC X-ray sources and GCs is D_max=0.181, and the probability P=0.068, which means we can reject the hypothesis that the two distributions are the same at the 90.0% confidence level. Finally, we study the correlation between X-ray luminosity (0.3-10 keV) and optical luminosity (in the V band) of the GC X-ray sources in M31, and find that there exits a weak relationship with the linear correlation coefficient r=0.36 at a confidence level of 98.0%.