ar X iv : a st ro - p h / 98 10 37 4 v 1 2 2 O ct 1 99 8 Evidence Against an Association Between Gamma - Ray Bursts and Type I

ar X iv : a st ro - p h / 98 10 25 1 v 1 1 6 O ct 1 99 8 X - ray bursts from 1

We report evidence of type-I X-ray bursting activity from the transient 1RXS J170930.2-263927 when it was in outburst early 1997. This identifies the source as a probable low-mass X-ray binary containing a neutron star. The error boxes of the detected bursts and of the persistent emission, as obtained with the Wide Field Cameras on board the BeppoSAX satellite, rule out an association with the ...

ar X iv : a st ro - p h / 98 10 37 1 v 1 2 2 O ct 1 99 8 ELLIPTICAL GALAXY DYNAMICS

ar X iv : h ep - p h / 98 10 33 5 v 1 1 3 O ct 1 99 8 Gamma - Ray Bursts and Dark Matter - a joint origin ?

ar X iv : a st ro - p h / 98 06 18 3 v 2 1 6 Ju l 1 99 8 The Edge of a Gamma Ray Burst Afterglow

We discuss the formation of spectral features in the decelerating ejecta of gamma-ray bursts, including the possible effect of inhomogeneities. These should lead to blueshifted and broadened absorption edges and resonant features, especially from H and He. An external neutral ISM could produce detectable H and He, as well as Fe X-ray absorption edges and lines. Hypernova scenarios may be diagno...

ar X iv : a st ro - p h / 98 10 38 9 v 1 2 3 O ct 1 99 8 Is Dark Matter made up of Massive Quark Objects ? 1

We suggest that dark matter is made up of massive quark objects that have survived from the Big Bang, representing the ground state of “baryonic” matter. Hence, there was no overall phase transition of the original quark matter, but only a split-up into smaller objects. We speculate that normal hadronic matter comes about through enforced phase transitions when such objects merge or collide, wh...