We present preliminary results of a follow-up survey which aims to characterise in detail those galaxies which hosted Type Ia supernovae found by the Supernova Cosmology Project. Our survey has two components: Hubble Space Telescope imaging with STIS and Keck spectroscopy with ESI, the goal being to classify each host galaxy into one of three broad morphological/spectral classes and hence to in...

We use different assumptions for the combination of dust extinction and star formation up to redshifts z > ∼ 5, as well as detailed modeling of supernova properties , to estimate the number of supernovae that should be observable with various instruments, in particular the NGST. In the model we use realistic light curves and spectral shapes that evolve with time for the different types supernov...

Supernova rates are directly coupled to high mass stellar birth and evolution. As such, they are one of the few direct measures of the history of cosmic stellar evolution. In this paper we describe an probabilistic technique for identifying supernovae within spectroscopic samples of galaxies. We present a study of 52 type Ia supernovae ranging in age from -14 days to +40 days extracted from a p...

As the shock and expanding shell of a supernova plow out through the circumstellar material at thousands of km s −1 , radio emission is generated. VLBI observations of this radio emission are presently the only means to directly image the expanding shell of any supernova much farther away than SN 1987A. The last decade has seen great progress in VLBI imaging of radio supernovae. In particular, ...

We show that the recently observed elemental abundance pattern of the carbon-rich metal-poor Damped Lyman α (DLA) system is in excellent agreement with the nucleosynthesis yields of faint core-collapse supernovae of primordial stars. The observed abundance pattern is not consistent with the nucleosynthesis yields of pair-instability supernovae. The DLA abundance pattern is very similar to that ...

We present evidence for a correlation between expansion velocities of the ejecta of Type II plateau supernovae and their bolometric luminosities during the plateau phase. This correlation permits one to standardize the candles and decrease the scatter in the Hubble diagram from ∼1 mag to a level of 0.4 and 0.3 mag in the V and I bands, respectively. When we restrict the sample to the eight obje...

Aims. Our aim is to show how different hypotheses about Type Ia supernova progenitors can affect Galactic chemical evolution. Supernovae Ia, in fact, are believed to be the main producers of Fe and the timescale with which Fe is restored into the interstellar medium depends on the assumed supernova progenitor model. This is a way of selecting the right progenitor model for supernovae Ia, a stil...

The last five years have seen growing challenges to the traditional paradigm of a core collapse supernova powered by the neutrino emission of a young proto-neutron star. Chief among these challenges are gamma-ray bursts (GRBs) and the supernovae that seem to accompany them. Here we review some recent and not so recent models for GRBs and supernovae in which strong magnetic fields, rotation, or ...

Estimates made in the 1970’s indicated that a supernova occurring within tens of parsecs of Earth could have significant effects on the ozone layer. Since that time improved tools for detailed modeling of atmospheric chemistry have been developed to calculate ozone depletion, and advances have been made also in theoretical modeling of supernovae and of the resultant gamma-ray spectra. In additi...

Type Ia Supernovae are in many aspects still enigmatic objects. Their observational and theoretical exploration is in full swing, but we still have plenty to learn about these explosions. Recent years have already witnessed a bonanza of supernova observations. The increased samples from dedicated searches have allowed the statistical investigation of Type Ia Supernovae as a class. The observati...