Asphericity in supernova explosions from late-time spectroscopy.

Asphericity in Supernova Explosions from Late - Time Spectroscopy 1

Optical polarimetric monitoring of the type II - plateau SN 2005 af ⋆

Aims. Core-collapse supernovae may show significant polarization that implies non-spherically symmetric explosions. We observed the type II-plateau SN 2005af using optical polarimetry in order to verify whether any asphericity is present in the supernova temporal evolution. Methods. We used the IAGPOL imaging polarimeter to obtain optical linear polarization measurements in R (five epochs) and ...

Spectropolarimetric diagnostics of thermonuclear supernova explosions.

Even at extragalactic distances, the shape of supernova ejecta can be effectively diagnosed by spectropolarimetry. We present results for 17 type Ia supernovae that allow a statistical study of the correlation among the geometric structures and other observable parameters of type Ia supernovae. These observations suggest that type Ia supernova ejecta typically consist of a smooth, central, iron...

Cosmic rays, stellar evolution, and supernova physics

Most cosmic rays are thought to be accelerated by the shocks of supernova explosions of very massive stars. Here we review one quantitative proposal, which predicted the spectral slopes, bend and cutoff about the cosmic ray spectrum across the spectral bend or “knee” near 3 10 eV in 1993. Many of the specific predictions have now been verified, and so it may be appropiate to investigate the con...

Spectropolarimetry of Supernovae

Overwhelming evidence has accumulated in recent years that supernova explosions are intrinsically 3-dimensional phenomena with significant departures from spherical symmetry. We review the evidence derived from spectropolarimetry that has established several key results: virtually all supernovae are significantly aspherical near maxim light; core-collapse supernovae behave differently than ther...