Title: What powers the 3000-day light curve of SN 2006gy?

Abstract

SN 2006gy was the most luminous supernova (SN) ever observed at the time of its discovery and the first of the newly defined class of superluminous supernovae (SLSNe). The extraordinary energetics of SN 2006gy and all SLSNe (>10⁵¹ erg) require either atypically large explosion energies (e.g. pair-instability explosion) or the efficient conversion of kinetic into radiative energy (e.g. shock interaction). The mass-loss characteristics can therefore offer important clues regarding the progenitor system. For the case of SN 2006gy, both a scattered and thermal light echo from circumstellar material (CSM) have been reported at later epochs (day ~800), ruling out the likelihood of a pair-instability event and leading to constraints on the characteristics of the CSM. Owing to the proximity of the SN to the bright host-galaxy nucleus, continued monitoring of the light echo has not been trivial, requiring the high resolution offered by the Hubble Space Telescope (HST) or ground-based adaptive optics (AO). Furthermore, we report detections of SN 2006gy using HST and Keck AO at ~3000 d post-explosion and consider the emission mechanism for the very late-time light curve. While the optical light curve and optical spectral energy distribution are consistent with a continued scattered-light echo, a thermal echomore » is insufficient to power the K'-band emission by day 3000. Instead, we present evidence for late-time infrared emission from dust that is radiatively heated by CSM interaction within an extremely dense dust shell, and we consider the implications on the CSM characteristics and progenitor system.« less

Authors:

Fox, Ori D. ^[1]; Smith, Nathan ^[2]; Ammons, S. Mark ^[3]; Andrews, Jennifer ^[2]; Bostroem, K. Azalee ^[4]; Cenko, S. Bradley ^[5]; Clayton, Geoffrey C. ^[6]; Dwek, Eli ^[7]; Filippenko, Alexei V. ^[8]; Gallagher, Joseph S. ^[9]; Kelly, Patrick L. ^[8]; Mauerhan, Jon C. ^[8]; Miller, Adam A. ^[10]; Van Dyk, Schuyler D. ^[11]

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+ Show Author Affiliations

1. Univ. of California, Berkeley, CA (United States); Space Telescope Science Institute, Baltimore, MD (United States)
2. Steward Observatory, Tucson, AZ (United States)
3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
4. Univ. of California, Davis, CA (United States)
5. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland, College Park, MD (United States)
6. Louisiana State Univ., Baton Rouge, LA (United States)
7. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
8. Univ. of California, Berkeley, CA (United States)
9. Univ. of Cincinnati Blue Ash College, Blue Ash, OH (United States)
10. Jet Propulsion Lab., Pasadena, CA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States)
11. IPAC/Caltech, Pasadena, CA (United States)

Publication Date:

Tue Oct 27 00:00:00 EDT 2015

Research Org.:

Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1352129

Report Number(s):

LLNL-JRNL-717863
Journal ID: ISSN 0035-8711

Grant/Contract Number:  

AC52-07NA27344

Resource Type:

Accepted Manuscript

Journal Name:

Monthly Notices of the Royal Astronomical Society

Additional Journal Information:

Journal Volume: 454; Journal Issue: 4; Journal ID: ISSN 0035-8711

Publisher:

Royal Astronomical Society

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; circumstellar matter; supernovae: general; supernovae: individual: SN 2006gy; dust; extinction; infrared: stars