Detection of X-ray bursts in the globular cluster NGC 6652

Zand, J. J. M. in 't; Verbunt, F.; Heise, J.; Muller, J. M.; Bazzano, A.; Cocchi, M.; Natalucci, L.; Ubertini, P.

Detection of X-ray bursts in the globular cluster NGC 6652

Authors

Description

Two type I X-ray bursts were detected from a position consistent with the transient X-ray source in NGC 6652 with the Wide Field Camera of the BeppoSAX satellite, strongly suggesting that this transient is a neutron star. Our detection brings to ten the number of X-ray sources in globular clusters in which a type I X-ray burst has been seen, out of twelve known bright sources. The statistical evidence that the fraction of low-mass X-ray binaries which contain a black hole accretor is smaller in globular clusters than in the galactic disk is suggestive, but as yet not compelling.
Published in A&A, 1998, vol. 329, L37; 5 pages, 3 figures