Exploring the Geometry of the Brightest Supernovae

Jennifer L. Hoffman, R.C. Thomas, Peter Nugent,
Douglas C. Leonard, and Alexei V. Filippenko

2005 AAS, 205, 7116
PDF (926 K)
 
In the hierarchy of supernova explosions, the most luminous events (MV ~ -20) belong to the subclass known as Type IIn. Though not all Type IIn's reach such huge brightnesses, spectra of these objects consistently reveal intense interaction between the supernova ejecta and dense circumstellar matter configurations; the prodigious optical output of the brightest Type IIn supernovae is powered by this interaction rather than by a process intrinsic to the explosion mechanism. In polarized light, Type IIn's show intriguing features such as multiple polarization axes and highly polarized emission lines offset from the lines in the flux spectrum. We investigate ways in which such polarization spectra can be produced at early times in a supernova's evolution by modeling the transfer of supernova spectra through circumstellar shells with various geometrical configurations. Our approach combines 3-D spectrum synthesis and Monte Carlo radiative transfer codes; we compare our results with high-quality spectropolarimetric observations of Type IIn supernovae.

J.L. Hoffman is supported by an NSF Astronomy & Astrophysics Postdoctoral Fellowship under award AST-0302123. This research uses the resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.
 

For more information, please send email to Jennifer.
January 20, 2005