Shell-shocked diffusion model for the light curve of sn 2006gy

Nathan Smith, Richard McCray

Research output: Contribution to journalArticle

131 Citations (Scopus)

Abstract

We explore a simple model for the high luminosity of SN 2006gy involving photon diffusion of shock-deposited thermal energy. The distinguishing property of the model is that the large "stellar" radius of ∼160 AU required to prevent adiabatic losses is not the true stellar radius, but rather, it is the radius of an opaque, unbound circumstellar envelope, created when ∼10 M was ejected in the decade before the supernova in an eruption analogous to that of η Carinae. The supernova light is produced primarily by diffusion of thermal energy following the passage of the blast wave through this shell. This model differs from traditional models of supernova debris interacting with an external circumstellar medium (CSM) in that here the shell is optically thick and the escape of radiation is delayed. We show that any model attempting to account for SN 2006gy's huge luminosity with radiation emitted by ongoing CSM interaction fails for the following basic reason: the CSM density required to achieve the observed luminosity makes the same circumstellar envelope opaque (r ≥ 300), forcing a thermal diffusion solution. In our model, the weaker CSM interaction giving rise to SN 2006gy's characteristic Type Hn spectrum and soft X-rays is not linked to the power source of the visual continuum; instead, it arises after the blast wave breaks free from the opaque shell into the surrounding wind. While a simple diffusion model can explain the gross properties of the early light curve of SN 2006gy, it predicts that the light curve must plummet rapidly at late times, unless an additional power source is present.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume671
Issue number1 PART 2
DOIs
StatePublished - 2007
Externally publishedYes

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light curve
shell
supernovae
luminosity
blasts
thermal energy
radii
envelopes
thermal diffusion
radiation
debris
volcanic eruptions
escape
energy
volcanic eruption
shock
interactions
continuums
photons
x rays

Keywords

  • Circumstellar matter -stars
  • Evolution -supernovae
  • Individual (sn 2006gy)

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Shell-shocked diffusion model for the light curve of sn 2006gy. / Smith, Nathan; McCray, Richard.

In: Astrophysical Journal, Vol. 671, No. 1 PART 2, 2007.

Research output: Contribution to journalArticle

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