ar X iv : a st ro - p h / 96 01 08 1 v 1 1 5 Ja n 19 96 Projection Effects in the Abell Catalogue

ar X iv : a st ro - p h / 96 01 12 9 v 1 2 3 Ja n 19 96 Is Her X - 1 a strange star

The possible identification of Her X-1 with a strange star (Li et al. 1995) is shown to be incorrect.

ar X iv : a st ro - p h / 97 01 22 8 v 1 2 9 Ja n 19 97 Large - scale Structures revealed by Wavelet Decomposition 1

ar X iv : a st ro - p h / 96 01 04 5 v 1 1 0 Ja n 19 96 The nature of the X - ray source in NGC 4151

Analysis of broad-band X/γ-ray spectra of NGC 4151 shows that the data are well modelled with an intrinsic spectrum due to thermal Comptonization with temperature ∼ 50 keV and X-ray spectral index α ∼ 0.4– 0.7. The variable X-ray spectrum pivots at ∼ 100 keV, which is consistent with the observed approximatly constant γ-ray spectrum. The observed UV/X-ray correlation can be explained by two spe...

ar X iv : a st ro - p h / 96 01 16 3 v 1 2 9 Ja n 19 96 Lagrangian Dynamics of Collisionless Matter

The non–linear dynamics of self–gravitating irrotational dust is analyzed in a general relativistic framework, using synchronous and comoving coordinates. Writing the equations in terms of the metric tensor of the spatial sections orthogonal to the fluid flow allows an unambiguous expansion in inverse powers of the speed of light. The Newtonian and post–Newtonian approximations are derived in L...

ar X iv : a st ro - p h / 96 01 19 1 v 1 3 1 Ja n 19 96 NGC 2915 . II . A Dark Spiral Galaxy With A Blue Compact Dwarf Core

This paper presents Australia Telescope Compact Array H I synthesis observations of the weak blue compact dwarf (BCD) galaxy NGC 2915. It is shown that NGC 2915 has the H I properties of a late type spiral galaxy (Sd Sm), including a double horn global profile, and H I spiral arms. The H I extends out to over five times the Holmberg radius, and 22 times the exponential scale length in the B ban...