Extraordinary Late - Time Infrared Emission of Type Iin Supernovae
نویسندگان
چکیده
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 erg s, 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 erg. A number of dust heating scenarios are considered, the most likely being an infrared echo powered by X-ray and UV emissions from the shock interaction with a dense circumstellar medium. Subject headings: supernovae: individual (SN 1995N, SN 1997ab, SN 1998S, SN 1999Z, SN 1999el) — dust — circumstellar matter — infrared: stars
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