Related papers: SN 1998bw/GRB 980425: Hypernova or Aspherical Expl…
The recent discovery of the unusual supernova SN1998bw and its apparent correlation with the gamma-ray burst GRB 980425 has raised new issues concerning both the GRB and supernovae. Although the spectra resemble those of TypeIc supernovae,…
Study of the polarization of supernovae has suggested that the core collapse process may be intrinsically strongly asymmetric. There is a tentative trend for supernova with smaller envelopes showing more polarization, with Type Ic having…
The discovery of the peculiar supernova (SN) 1998bw and its possible association with the gamma-ray burst (GRB) 980425$^{1,2,3}$ provide new clues to the understanding of the explosion mechanism of very massive stars and to the origin of…
SN 1998bw is an unusual Type Ic supernova that may be associated with the $\gamma$-ray burst GRB 980425. We use a synchrotron self-absorption model for its radio emission to deduce that the synchrotron-emitting gas is expanding into a…
Recently a Type Ic supernova, SN 1998bw, was discovered coincident with a gamma-ray burst, GRB 980425. The supernova had unusual radio, optical, and spectroscopic properties. We explore here models based upon helium stars in the range 9 -…
Supernova (SN) 1998bw and gamma-ray burst (GRB) 980425 offer the first direct evidence that supernovae are the progenitors of some GRBs. However, this burst was unusually dim, smooth and soft compared to other bursts with known afterglows.…
The association of gamma-ray bursts (GRBs) and core-collapse supernovae (SNe) of Type Ib and Ic was motivated by the detection of SN 1998bw in the error box of GRB 980425 and the now-secure identification of a SN 1998bw-like event in the…
The spatiotemporal coincidence of supernova (SN) 1998bw and gamma-ray burst (GRB) 980425 and this supernova's unusual optical and radio properties have prompted many theoretical models that produce GRBs from supernovae. We review the…
Refined one- and two-dimensional models for the nebular spectra of the hyper-energetic Type Ic supernova (SN) 1998bw, associated with the gamma-ray burst GRB980425, from 125 to 376 days after B-band maximum are presented. One dimensional,…
A refined model for the unusual Type Ic supernova 1998bw, discovered as the optical counterpart of GRB980425, is presented, and synthetic light curves and spectra are compared with the observations. The first 30 days of the light curve and…
We discuss the properties of the hyper-energetic Type Ic supernovae (SNe Ic) 1998bw and 1997ef and Type IIn supernova (SN IIn) 1997cy. SNe Ic 1998bw and 1997ef are characterized by their large luminosity and the very broad spectral…
Supernova SN 1998bw exploded in the same direction and at the same time as the gamma-ray burst GRB 980425. Here we report radio observations of this type Ic supernova, beginning 4 days after the gamma-ray burst. At its peak the radio source…
Aspherical explosion models for the hypernova (hyper-energetic supernova) SN 1998bw are presented. Nucleosynthesis in aspherical explosions is examined with a two-dimensional hydrodynamical code and a detailed nuclear reaction network.…
We report 139 photometric observations through the B, V, and I filters of the supernova SN 1998bw, an object which is associated with the Gamma-Ray Burst GRB 980425. Detailed light curves of this unique supernova can be compared to…
There are hints that nearby Type Ia supernovae may be a little different than those at large redshift. Confidence in the conclusion that there is a cosmological constant and an accelerating Universe thus still requires the hard work of…
Supernovae 1998bw and its corresponding relativistically expanding radio source are coincident with the \grb source GRB 980425. We show that of six recent SN Ib/c for which an outburst epoch can be estimated with some reliability, four have…
The gamma ray burst (GRB) 980425 is distinctive in that it seems to be associated with supernova (SN) 1998bw, has no X-ray afterglow, and has a single peak light curve and a soft spectrum. The supernova is itself unusual in that its…
The spatial and temporal coincidence of a GRB and a supernova explosion (1998bw) on 25 April 1998 has raised conjectures on the physical connection between the two phenomena, and in general on the association of GRBs with supernovae, at…
The probable association with GRB 980425 immediately put SN 1998bw at the forefront of supernova research. Here, we present revised late-time BVRI light curves of the supernova, based on template images taken at the VLT. To follow the…
Some gamma ray bursts may be produced by supernovae exploding in close massive binary systems (type Ib/c supernovae) as suggested by the recent observation of SN 1998bw/GRB 980425. We propose that high energy radiation observed in such…