Modelling late-time red-blue line asymmetries in the spectra of core-collapse supernovae

Abstract:
Spitzer mid-IR observations of core-collapse supernovae have revealed dust formation to be common during the first 1000 days 
after explosion, while Herschel far-IR observations of supernova remnants such as Cas A, SN 1987A and the Crab Nebula have 
measured up to 0.1-0.5 solar masses of cool dust to be present in their ejecta (Barlow et al. 2010, Matsuura et al. 2011, Gomez 
et al. 2012). These estimates are based on fitting the observed infrared continuum emission but once Herschel completes its 
mission in 2013 there will be a long wait for comparable or better spaceborne thermal infrared facilities to become available.

The absorption of optical or near-IR radiation by newly-formed dust within the ejecta of supernovae can result in an asymmetry 
between the red and blue shifted components, with the redwards emission from the far side of the ejecta undergoing greater 
absorption (Lucy et al. 1989). Such red-blue asymmetries are frequently observed in the late-time (T>400d) spectra of 
supernova ejecta and there is a large database of such observations available. We present here a series of Monte Carlo 
models investigating the effects that influence the red/blue asymmetry, in order to assess the utility of line profile fitting for 
quantifying the masses of dust formed in supernova ejecta.