We present 29 optical spectra of the normal Type Ia SN 1998aq, ranging from 9 days before to 241 days after the time of maximum brightness. This spectrocopic data set, together with photometric data presented elsewhere, makes SN 1998aq one of the best observed Type Ia supernovae at optical wavelengths. We use the parameterized supernova synthetic–spectrum code Synow to study line identification...

The venerable study of cosmic explosions is over a century old. However, until recently, there has existed a glaring six-magnitude luminosity gap between the brightest novae and faintest supernovae. To find optical transients that are fainter, faster, and rarer than supernovae, we designed a systematic search: the Palomar Transient Factory. Theorists predict a variety of mechanisms to produce t...

This manuscript reviews recent progress in our understanding of the nucleosynthesis of medium and heavy elements in supernovae. Recent hydrodynamical models of core-collapse supernovae show that a large amount of proton rich matter is ejected under strong neutrino fluxes. This matter constitutes the site of the ν p-process where antineutrino absorption reactions catalyze the nucleosynthesis of ...

A parameterized supernova synthetic–spectrum code is used to study line identifications in the photospheric–phase spectra of the peculiar Type Ia SN 1991T, and to extract some constraints on the composition structure of the ejected matter. The inferred composition structure is not like that of any hydrodynamical model for Type Ia supernovae. Evidence that SN 1991T was overluminous for an SN Ia ...

Subject of this contribution is to demonstrate that the observed faintness of the supernovae at the high redshift can be considered as a manifestation of quantum effects at cosmological scales. We show that observed redshift distribution of coordinate distances to the type Ia supernovae can be explained by the local manifestations of quantum fluctuations of the cosmological scale factor about i...

We examine the utility of very high redshift Type Ia supernovae for cosmology and systematic uncertainty control. Next generation space surveys such as the Supernova/Acceleration Probe (SNAP) will obtain thousands of supernovae at z > 1.7, beyond the design redshift for which the supernovae will be exquisitely characterized. We find that any z & 2 standard candles’ use for cosmological paramete...

Supernova explosions are among the most energetic phenomena in the known universe. There are suggestions that cosmic rays up to EeV energies might be accelerated in the young supernova shell on time scales of a few weeks to years, which would lead to TeV neutrino radiation. The data taken with the AMANDA neutrino telescope in the years 2000 to 2006 is analysed with a likelihood approach in orde...

Received ; accepted – 2 – ABSTRACT A systematic survey of ions that could be responsible for features in the optical spectra of supernovae is carried out. Six different compositions that could be encountered in supernovae are considered. For each composition, the LTE optical depth of one of the strongest optical lines of each ion is plotted against temperature. For each ion that can realistical...

INTRODUCTION Supernovae and gamma ray bursters (possibly caused by “hypernovae”) are the most energetic known events in the Universe. Supernovae release approximately 10 ergs of energy in the form of photons, neutrinos, and kinetic energy imparted to debris from the explosion. Hypernovae release approximately 10 ergs of gamma ray energy alone (1). Some researchers have speculated that nearby su...

Several progenitor scenarios have been suggested for Type Ia supernovae. Here we discuss the consequences for the explosion mechanism and for observables of some of them, which are explored by means of multi-dimensional hydrodynamic and radiation transfer simulations. While the observables predicted from delayed detonations of Chandrasekhar-mass white dwarfs agree reasonably well with the data,...