ar X iv : a st ro - p h / 01 07 00 9 v 1 1 J ul 2 00 1 Theory of GRB Afterglow

ar X iv : a st ro - p h / 01 09 00 9 v 1 2 S ep 2 00 1 Optical Observations of the Dark Gamma - Ray Burst GRB 000210

We report on optical observations on GRB 000210 obtained with the 2.56m Nordic Optical Telescope and the 1.54-m Danish Telescope starting 12.4 hours after the gamma-ray event. The content of the X-ray error box determined by the Chandra satellite is discussed.

ar X iv : a st ro - p h / 01 09 02 0 v 1 3 S ep 2 00 1 GRB 000301 C : a possible short / intermediate duration burst connected to a DLA system

We discuss two main aspects of the GRB 000301C afterglow [1,2]; its short duration and its possible connection with a Damped Lyα Absorber (DLA). GRB 000301C falls in the short class of bursts, though it is consistent with belonging to the proposed intermediate class or the extreme short end of the distribution of long-duration GRBs. Based on two VLT spectra we estimate the H I column density to...

ar X iv : a st ro - p h / 05 07 06 6 v 1 4 J ul 2 00 5 Multiband Echo Tomography of Sco X - 1

ar X iv : a st ro - p h / 00 07 10 5 v 1 8 J ul 2 00 0 THE BROAD BAND SPECTRUM AND VARIABILITY OF SEYFERT 1

Recent results on the X–ray spectrum and variability of Seyfert 1 galaxies are reviewed. New spectral results from BeppoSAX observations are also presented and briefly discussed.

ar X iv : a st ro - p h / 03 12 17 7 v 1 5 D ec 2 00 3 Was the X - ray Afterglow of GRB 970815 Detected ?

GRB 970815 was a well-localized gamma-ray burst (GRB) detected by the All-Sky Monitor (ASM) on the Rossi X-Ray Timing Explorer (RXTE) for which no afterglow was identified despite follow-up ASCA and ROSAT pointings and optical imaging to limiting magnitude R > 23. While an X-ray source, AX/RX J1606.8+8130, was detected just outside the ASM error box, it was never associated with the GRB because...