Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 21, 2015 | Submitted + Published
Journal Article Open

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 (>10^(51) 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). Here, 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 echo 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.

Additional Information

© 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2015 September 29. Received 2015 September 17; in original form 2015 July 10. First published online October 28, 2015. This work is based on observations made with the NASA/ESA HST, obtained from the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555. We are grateful to the STScI Help Desk for their assistance with the HST data. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA; the observatory was made possible by the generous financial support of the W. M. Keck Foundation. The Keck observations were made possible by the ToO program. We thank the staff of the Keck Observatory for their assistance with the observations, as well as efforts by Sam Ragland and Mark Morris. Melissa L. Graham and WeiKang Zheng helped obtain and reduce the Keck spectra. We wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Financial support for ODF was provided by NASA through grant GO-13287 from STScI. AVF and his group acknowledge generous financial assistance from the Christopher R. Redlich Fund, the TABASGO Foundation, and NSF grant AST-1211916. The research by SMA is supported by the US Department of Energy through the Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Attached Files

Published - MNRAS-2015-Fox-4366-78.pdf

Submitted - 1509.06407v1.pdf

Files

1509.06407v1.pdf
Files (5.8 MB)
Name Size Download all
md5:c89809e4172e8beecd94faa75469e739
1.2 MB Preview Download
md5:a6234137d9bc3bca4c411820f7c476b2
4.6 MB Preview Download

Additional details

Created:
August 20, 2023
Modified:
October 25, 2023