ar X iv : 0 80 9 . 12 45 v 1 [ as tr o - ph ] 7 S ep 2 00 8 Massive stars in their death - throes

ar X iv : 0 80 9 . 12 45 v 2 [ as tr o - ph ] 1 1 Se p 20 08 Massive stars in their death - throes

The study of the stars that explode as supernovae used to be a forensic study, working backwards from the remnants of the star. This changed in 1987 when the first progenitor star was identified in pre-explosion images. Currently there are 8 detected progenitors with another 21 non-detections, for which only a limit on the pre-explosion luminosity can be placed. This new avenue of supernova res...

ar X iv : 0 70 9 . 05 45 v 1 [ as tr o - ph ] 4 S ep 2 00 7 Did supermassive black holes form by direct collapse ? Mitchell

Rapid infall of gas in the nuclei of galaxies could lead to the formation of black holes by direct collapse, without first forming stars. Black holes formed in this way would have initial masses of a few M⊙, but would be embedded in massive envelopes that would allow them to grow at a highly super-Eddington rate. Thus, seed black holes as large as 103 − 10M⊙ could form very rapidly. I will sket...

ar X iv : 0 70 9 . 08 74 v 1 [ as tr o - ph ] 6 S ep 2 00 7 How Efficient is Rotational Mixing in Massive Stars ?

The VLT-Flames Survey for Massive Stars [1, 2] provides precise measurements of rotational velocities and nitrogen surface abundances of massive stars in the Magellanic Clouds. Specifically, for the first time, such abundances have been estimated for stars with significant rotational velocities. This extraordinary data set gives us the unique possibility to calibrate rotationally and magnetical...

ar X iv : 0 70 5 . 32 58 v 1 [ as tr o - ph ] 2 2 M ay 2 00 7 Disks around Young Binary Stars

ar X iv : 0 70 9 . 08 61 v 1 [ as tr o - ph ] 6 S ep 2 00 7 The population of GRB hosts

The properties of their hosts provide important clues to the progenitors of different classes of gamma-ray bursts (GRBs). The hosts themselves also constitute a sample of high-redshift star-forming galaxies which, unlike most other methods, is not selected on the luminosities of the galaxies themselves. We discuss what we have learnt from and about GRB host galaxies to date.