LMC X-2 : an extragalactic bulge-type source.
Parmar, A. N.; Motch, C.; Beuermann, K.; Pakull, M.; van der Klis, M.; Bonnet-Bidaud, J. M.
France, Germany, Netherlands
Abstract
The X-ray source LMC X-2 was observed with EXOSAT for ~8 h on February 2, 1984 with simultaneous photometric and spectroscopic optical coverage. The source was seen at a luminosity of L_x_ ~1.5 10^38^ erg s^-1^ with a mean X-ray spectrum can be described equally well by either the superposition of thermal emission from an optically thin (T_th_ ~5 keV) plasma and a blackbody (T_bb_ ~1.3 keV) or by a comptonized thermal (T__co_ ~3 keV) model. The mean X-ray spectrum is found to be very similar to those of the bright galactic buldge sources. The source is only moderately variable in X-rays with spectral variations similar to those seen from Sco X-1 in quiescence. No coherent periodic (0.016-2500 s) pulsations were detected. Large photometric optical variations are present which suggest an orbital period of 64h although at a low level of significance. There is no clear correlation between X-ray and variations.