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Dark Bursts in the Swift Era: The Palomar 60 Inch-Swift Early Optical Afterglow Catalog

Cenko, S. B. and Kelemen, J. and Harrison, F. A. and Fox, D. B. and Kulkarni, S. R. and Kasliwal, M. M. and Ofek, E. O. and Rau, A. and Gal-Yam, A. and Frail, D. A. and Moon, D.-S. (2009) Dark Bursts in the Swift Era: The Palomar 60 Inch-Swift Early Optical Afterglow Catalog. Astrophysical Journal, 693 (2). pp. 1484-1493. ISSN 0004-637X. doi:10.1088/0004-637X/693/2/1484.

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We present multicolor optical observations of long-duration γ-ray bursts (GRBs) made over a three-year period with the robotic Palomar 60 inch telescope (P60). Our sample consists of all 29 events discovered by Swift for which P60 began observations less than 1 hr after the burst trigger. We were able to recover 80% of the optical afterglows from this prompt sample, and we attribute this high efficiency to our red coverage. Like Melandri et al. (2008), we find that a significant fraction (≈50%) of Swift events show a suppression of the optical flux with regard to the X-ray emission (the so-called "dark" bursts). Our multicolor photometry demonstrates this is likely due in large part to extinction in the host galaxy. We argue that previous studies, by selecting only the brightest and best-sampled optical afterglows, have significantly underestimated the amount of dust present in typical GRB environments.

Item Type:Article
Related URLs:
URLURL TypeDescription
Cenko, S. B.0000-0003-1673-970X
Harrison, F. A.0000-0003-2992-8024
Fox, D. B.0000-0002-3714-672X
Kulkarni, S. R.0000-0001-5390-8563
Kasliwal, M. M.0000-0002-5619-4938
Ofek, E. O.0000-0002-6786-8774
Rau, A.0000-0001-5990-6243
Gal-Yam, A.0000-0002-3653-5598
Moon, D.-S.0000-0003-4200-5064
Additional Information:© 2009 The American Astronomical Society. Received 2008 June 26; accepted 2008 September 12; published 2009 March 9. We wish to thank D. A. Kann for valuable comments on this manuscript. P60 operations are funded in part by NASA through the Swift Guest Investigator Program (Grant Number NNG06GH61G). S.B.C. was supported by a NASA Graduate Student Research Program Fellowship at Caltech, and acknowledges support from Gary and Cynthia Bengier, as well as from Richard and Rhoda Goldman, to the research of Alex Filippenko’s group at U.C. Berkeley. M.M.K. would like to acknowledge the Moore Foundation for the Hale Fellowship supporting her graduate studies. A.G. acknowledges support by the Benoziyo Center for Astrophysics and the William Z. and Eda Bess Novick New Scientists Fund at the Weizmann Institute. This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester. This research has made use of the USNOFS Image and Catalogue Archive operated by the United States Naval Observatory, Flagstaff Station. Facilities: PO:1.5m (), Swift (XRT)
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Gordon and Betty Moore FoundationUNSPECIFIED
Benoziyo Center for AstrophysicsUNSPECIFIED
Eda Bess Novick New Scientists Fund at the Weizmann InstituteUNSPECIFIED
Subject Keywords:gamma rays: bursts
Issue or Number:2
Record Number:CaltechAUTHORS:20090624-132438395
Persistent URL:
Official Citation:Dark Bursts in the Swift Era: The Palomar 60 Inch-Swift Early Optical Afterglow Catalog S. B. Cenko, J. Kelemen, F. A. Harrison, D. B. Fox, S. R. Kulkarni, M. M. Kasliwal, E. O. Ofek, A. Rau, A. Gal-Yam, D. A. Frail, and D.-S. Moon 2009 ApJ 693 1484-1493 doi: 10.1088/0004-637X/693/2/1484
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14446
Deposited By: Tony Diaz
Deposited On:29 Aug 2009 00:44
Last Modified:08 Nov 2021 23:11

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