Search results for "SUPERNOVA"

Type-II Supernovae and Neutrino Magnetic Moment

1998

The present solar and atmospheric neutrino data together with the LSND results and the presence of hot dark matter (HDM) suggest the existence of a sterile neutrino at the eV scale. We have reanalysed the effect of resonant {\sl sterile} neutrino conversions induced by neutrino magnetic moments in a type-II supernova. We analyse the implications of $\nu_e-\nu_s$ and $\bar{\nu}_e-\bar{\nu}_s$ ($\nu_s$ denotes sterile neutrino) conversions for the supernova shock re-heating, the detected $\bar\nu_e$ signal from SN1987A and the $r$-process nucleosynthesis hypothesis. Using reasonable magnetic field profiles we determine the sensitivity of these three arguments to the relevant neutrino paramete…

Heavy Elements and Age Determinations

2002

The age of the universe, measured from the Big Bang to the present, is at the focus of cosmology. Its determination relies, however, on the use of stellar objects or their products. Stellar explosions, like type Ia supernovae serve as standard(izable) candles to measure the expansion of the universe. Hertzsprung—Russell diagrams of globular clusters can determine the age of such clusters and thus are lower limits of the age of the galaxy and therefore also the universe. Some nuclear isotopes with half-lives comparable to the age of galaxies (and the universe) can serve as clocks (chronometers) for the duration of nucleosynthesis. The isotopes 238U and 232Th with half-lives of 4.5 × l09 and …

The Bequest of a Supernova

2012

Hanabi translates as “fireworks”, but the Japanese expression is formed by joining the kanjis “hana”, one of whose meanings is “flower”, and “bi”, “fire”. That’s literally “fire flower”.

Dust Envelope in Young Supernova Remnants

1974

As stated by Hoyle and Wickramasinghe (1970), hereafter referred to as HW, a significant fraction of the mass ejected by exploding supernovae may condense into solid particles during the expansion phase following explosion. Hence, observable effects on supernova light curves are to be expected.

AN EXTENDED THOMAS-FERMI CALCULATION OF SUPERNOVA MATTER

1984

The three-ring structure of Supernova 1987A

1995

IceCube Sensitivity for Low-Energy Neutrinos from Nearby Supernovae ( Corrigendum )

2014

Keywords: neutrinos ; supernovae: general ; instrumentation: detectors ; errata ; addenda Reference EPFL-ARTICLE-198916doi:10.1051/0004-6361/201117810eView record in Web of Science Record created on 2014-05-19, modified on 2017-05-12

Discovery of shell-like radio-structure in SN1993J

1995

The radio-luminous supernova SN 1993J in M81 offers an unprecedented opportunity to study with high linear resolution the details of the growth of a supernova radio structure by means of the VLBI technique.

Multi-Wavelength VLA Observations of the Young Supernova SN 1993J

2003

We present continuum VLA measurements of SN1993J in M81 taken on 17 and 21 December 2000, about 2820 days after the supernova explosion, spanning the frequency range from 0.32 to 14.9 GHz. These observations aimed at discerning the main absorbing processes acting in SN1993J at late epochs. We discuss three models for the late radio emission of SN1993J: (i) a simple power-law spectrum, (ii) a power-law spectrum free-free absorbed by a screen of homogeneously distributed ionized gas, and (iii) a power-law spectrum free-free absorbed by a “clumpy” medium. We find that the best fit to the data is yielded by a power-law spectrum free-free absorbed by either a homogeneous, or a clumpy, distributi…

Monitoring of the prompt radio emission from the unusual supernova 2004dj in NGC2403

2005

Supernova 2004dj in the nearby spiral galaxy NGC2403 was detected optically in July 2004. Peaking at a magnitude of 11.2, this is the brightest supernova detected for several years. Here we present Multi-Element Radio Linked Interferometer Network (MERLIN) observations of this source, made over a four month period, which give a position of R.A. = 07h37m17.044s, Dec =+65deg35'57.84" (J2000.0). We also present a well-sampled 5 GHz light curve covering the period from 5 August to 2 December 2004. With the exception of the unusual and very close SN 1987A, these observations represent the first detailed radio light curve for the prompt emission from a Type II-P supernova.