The atoll source 4U 1608-52 is not a Z source

Abstract

We have studied the spectral and timing behaviour of the atoll source 4U 1608-52. We find that the timing behaviour of 4U 1608-52 is almost identical to that of the atoll sources 4U 0614+09 and 4U 1728-34. Recently Muno, Remillard & Chakrabarty (2002) and Gierlinski & Done (2002) suggested that the atoll sources trace out similar three-branch patterns as the Z sources. The timing behaviour is not consistent with the idea that 4U 1608-52 traces out a three-branched Z shape in the color-color diagram along which the timing properties vary gradually.

Proceedings of the 4th Microquasar Workshop, 2002, eds. Ph Durouchoux, Y. Fuchs and J. Rodriguez, to be published by the Center for Space Physics: Kolkata