The Type IIn supernova 1995N was discovered about 10 months after its likely explosion date, at a distance of about 24Mpc in the galaxy MCG-02-38-17. It is a bright and long-lived X-ray and radio source, indicating strong interaction between its ejecta and the pre-existing circumstellar medium (CSM). The supernova was detected as an infrared point source in Spitzer and WISE observations about 15 years after its explosion. This emission has been attributed to 0.12 M☉ of CSM dust illuminated by the supernova flash and thermally echoing. We argue, however, that a CSM echo is unlikely given the required geometry of the echoing material. We propose that the emission is due to about 0.2 M☉ of newly formed dust in the supernova ejecta, heated externally by the interaction of the ejecta with the CSM. We present radiative transfer models of the spectral energy distribution, and of asymmetric emission lines, which support this scenario.
Supernova Remnants: An Odyssey in Space after Stellar Death II
- Pub Date:
- June 2019