Статья

DARK BURSTS IN THE<i>SWIFT</i>ERA: THE PALOMAR 60 INCH-<i>SWIFT</i>EARLY OPTICAL AFTERGLOW CATALOG

S. B. CenkoDepartment of Astronomy, 601 Campbell Hall, University of California, Berkeley, CA 94720, USAJ. KelemenKonkoly Observatory, H-1525, Box 67, Budapest, HungaryFiona HarrisonSpace Radiation Laboratory, MS 220-47, California Institute of Technology, Pasadena, CA 91125, USA; [email protected]D. B. FoxDepartment of Astronomy & Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802, USAS. R. KulkarniDepartment of Astronomy, Mail Stop 105-24, California Institute of Technology, Pasadena, CA 91125, USAM. M. KasliwalDepartment of Astronomy, Mail Stop 105-24, California Institute of Technology, Pasadena, CA 91125, USAE. O. OfekDepartment of Astronomy, Mail Stop 105-24, California Institute of Technology, Pasadena, CA 91125, USAA. RauDepartment of Astronomy, Mail Stop 105-24, California Institute of Technology, Pasadena, CA 91125, USAA. Gal‐YamBenoziyo Center for Astrophysics, Weizmann Institute of Science, Rehovot 76100, IsraelD. A. FrailNational Radio Astronomy Observatory, P.O. Box 0, 1003 Lopezville Road, Socorro, NM 87801, USADae‐Sik MoonDepartment of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada

2009en

ABI

Аннотация

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.\n

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Идентификаторы

DOI: 10.1088/0004-637x/693/2/1484

Цитирования и источники

Цитирований: 3Использованных источников: 0

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