Evidence for dust destruction from the early-time colour change of GRB 120119A
- Creators
- Morgan, Adam N.
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Perley, Daniel A.
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Cenko, S. Bradley
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Bloom, Joshua S.
- Cucchiara, Antonino
- Richards, Joseph W.
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Filippenko, Alexei V.
- Haislip, Joshua B.
- LaCluyze, Aaron
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Corsi, Alessandra
- Melandri, Andrea
- Cobb, Bethany E.
- Gomboc, Andreja
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Horesh, Assaf
- James, Berian
- Li, Weidong
- Mundell, Carole G.
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Reichart, Daniel E.
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Steele, Iain
Abstract
We present broad-band observations and analysis of Swift gamma-ray burst (GRB) 120119A. Our early-time afterglow detections began under 15 s after the burst in the host frame (redshift z = 1.73), and they yield constraints on the burst energetics and local environment. Late-time afterglow observations of the burst show evidence for a moderate column of dust (A_V ≈ 1.1 mag) similar to, but statistically distinct from, dust seen along Small Magellanic Cloud sightlines. Deep late-time observations reveal a dusty, rapidly star-forming host galaxy. Most notably, our early-time observations exhibit a significant red-to-blue colour change in the first ∼200 s after the trigger at levels heretofore unseen in GRB afterglows. This colour change, which is coincident with the final phases of the prompt emission, is a hallmark prediction of the photodestruction of dust in GRB afterglows. We test whether dust-destruction signatures are significantly distinct from other sources of colour change, namely a change in the intrinsic spectral index β. We find that a time-varying power-law spectrum alone cannot adequately describe the observed colour change, and allowing for dust destruction (via a time-varying A_V) significantly improves the fit. While not definitively ruling out other possibilities, this event provides the best support yet for the direct detection of dust destruction in the local environment of a GRB.
Additional Information
© 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. First published online: March 27, 2014. Accepted 2014 February 19. Received 2014 January 31; in original form 2013 May 8. PAIRITEL is operated by the Smithsonian Astrophysical Observatory (SAO) and was made possible by a grant from the Harvard University Milton Fund, a camera loan from the University of Virginia, and continued support of the SAO and UC Berkeley. The PAIRITEL project is further supported by NASA/Swift Guest Investigator grants NNX10AI21G and NNX12AD73G. We utilized observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the NSF (USA), the Science and Technology Facilities Council (UK), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministèrio da Ciência, Tecnologia e Inovação (Brazil), and Ministerio de Ciencia, Tecnología e Innovaciόn Productiva (Argentina). The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. KAIT and its ongoing operation were made possible by donations from Sun Microsystems, Inc., the Hewlett-Packard Company, AutoScope Corporation, Lick Observatory, the NSF, the University of California, the Sylvia and Jim Katzman Foundation, and the TABASGO Foundation. 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. We wish to extend special thanks to those of Hawaiian ancestry on whose sacred mountain we are privileged to be guests. We are grateful to the staffs at the Gemini, Keck, and Lick Observatories for their assistance. This publication has made use of data obtained from the Swift interface of the High-Energy Astrophysics Archive (HEASARC), provided by NASA's Goddard Space Flight Center.We sincerely thank the Swift team for the rapid public dissemination, calibration, and analysis of the Swift data. We also thank Scott Barthelmy for his invaluable efforts in creating and maintaining the GCN system. We thank the anonymous referee for useful comments on this paper. We also thank Alex Kann for providing helpful suggestions to the text. CGM acknowledges support from the Royal Society. AVF's group at UC Berkeley has received generous financial assistance from Gary and Cynthia Bengier, the Christopher R. Redlich Fund, the Richard and Rhoda Goldman Fund, the TABASGO Foundation, NSF grant AST-1211916, and NASA/Swift grants NNX10AI21G and NNX12AD73G. AG acknowledges funding from the Slovenian Research Agency and from the Centre of Excellence for Space Science and Technologies SPACE-SI, an operation partly financed by the European Union, the European Regional Development Fund, and the Republic of Slovenia. Support for this work was provided by NASA to DAP through Hubble Fellowship grant HST-HF-51296.01-A awarded by the Space Telescope Science Institute, which is operated for NASA by AURA, Inc., under contract NAS 5-26555. We dedicate this paper to the memory of Weidong Li, who developed the software for KAIT automatic follow-up observations of GRBs; we deeply miss his friendship and collaboration, which were tragically taken away from us much too early.Attached Files
Published - MNRAS-2014-Morgan-1810-23.pdf
Submitted - 1305.1928v1.pdf
Supplemental Material - Table6_ascii.txt
Files
Additional details
- Eprint ID
- 46018
- Resolver ID
- CaltechAUTHORS:20140530-145017040
- Harvard University Milton Fund
- NNX10AI21G
- NASA
- NNX12AD73G
- NASA
- Science and Technology Facilities Council (STFC)
- Sun Microsystems, Inc.
- Hewlett-Packard Company
- AutoScope Corporation
- Lick Observatory
- University of California
- Sylvia and Jim Katzman Foundation
- TABASGO Foundation
- W. M. Keck Foundation
- Royal Society
- Gary and Cynthia Bengier
- Christopher R. Redlich Fund
- Richard and Rhoda Goldman Fund
- AST-1211916
- NSF
- Slovenian Research Agency
- Centre of Excellence for Space Science and Technologies SPACE-SI
- European Union
- European Regional Development Fund
- HST-HF-51296.01-A
- NASA Hubble Fellowship
- NAS 5-26555
- NASA
- Created
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2014-05-30Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field