Optical and near-IR observations of SN 1998bw

SN 1998bw, especially after the discovery of GRB 030329/SN 2003dh, seems to be the equivalent of the Rosetta stone for the SN/GRB connection. In this paper I review optical and near IR observations that have been carried out for this uncanny object, which has probably confirmed suspicions and ideas originally formulated in the early seventies of last century.Comment: 9 pages, 7 figures. Invited review to the IAU Colloquium n. 192, SUPERNOVAE: ten years of SN 1993J, Valencia (Spain

The optical afterglow and host galaxy of GRB 000926

We present the discovery of the Optical Transient (OT) of the long-duration gamma-ray burst GRB 000926. The optical transient was detected independently with the Nordic Optical Telescope and at Calar Alto 22.2 hours after the burst. At this time the magnitude of the transient was R = 19.36. The transient faded with a decay slope of about 1.7 during the first two days after which the slope increased abruptly (within a few hours) to about 2.4. The light-curve started to flatten off after about a week indicating the presence of an underlying extended object. This object was detected in a deep image obtained one month after the GRB at R=23.87+/-0.15 and consists of several compact knots within about 5 arcsec. One of the knots is spatially coincident with the position of the OT and hence most likely belongs to the host galaxy. Higher resolution imaging is needed to resolve whether all the compact knots belong to the host galaxy or to several independent objects. In a separate paper we present a discussion of the optical spectrum of the OT, and its inferred redshift (Møller et al., in prep.). Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden. Based on observations made at the 2.2-m telescope of the German-Spanish Calar Alto Observatory. Based on observations made with the Isaac Newton Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias

The Gas Reservoir for present day Galaxies: Damped Lyalpha Absorption Systems

. We present results from an ongoing search for galaxy counterparts of a subgroup of Quasar Absorption Line Systems called Damped Lyff Absorbers (DLAs). DLAs have several characteristics that make them essential in the process of understanding how galaxies formed in the early universe and evolved to the galaxies we see today in the local universe. Finally we compare DLAs with recent findings of a population of starforming galaxies at high redshifts, so called Lyman-break galaxies. 1. Introduction Damped Lyff Absorbers are the objects with highest HI column density of QSO absorption line systems. QSO absorption line systems are intergalactic material or in rare cases even galaxies that lie along the line of sight to background QSOs. In the spectrum of the background QSOs QSO absorption line systems manifest themselves primarily in thousands of Lyff absorption lines on the blue side of the QSO Lyff emission line - the so called Lyff forest. In a simplified picture each Lyff absorption l..

A very energetic supernova associated with the -ray burst of 29 March 2003

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