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Extraordinary Late-Time Infrared Emission of Type IIn Supernovae

C. L. Gerardy·R. A. Fesen·K. Nomoto·P. Garnavich·S. Jha·P. M. Challis·R. P. Kirshner·P. Hoeflich·J. C. Wheeler
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Abstract

Near-Infrared (NIR) observations are presented for five Type IIn supernovae (SN 1995N, SN 1997ab, SN 1998S, SN 1999Z, and SN 1999el) that exhibit strong infrared excesses at late times (t >= 100 d). H- and K-band emission from these objects is dominated by a continuum that rises toward longer wavelengths. The data are interpreted as thermal emission from dust, probably situated in a pre-existing circumstellar nebula. The IR luminosities implied by single temperature blackbody fits are quite large,> 10^(41 - 42) erg s^-1, and the emission evolves slowly, lasting for years after maximum light. For SN 1995N, the integrated energy release via IR dust emission was 0.5 -- 1 * 10^50 erg. A number of dust heating scenarios are considered, the most likely being an infrared echo poweredby X-ray and UV emissions from the shock interaction with a dense circumstellar medium.

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C. L. Gerardy, R. A. Fesen, K. Nomoto, P. Garnavich, S. Jha, P. M. Challis, R. P. Kirshner, P. Hoeflich, J. C. Wheeler. 2002-04-27. Extraordinary Late-Time Infrared Emission of Type IIn Supernovae. https://doi.org/10.1086/341430

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