GRB 081029: A Gamma-Ray Burst with a Multi-component Afterglow

Stephen T. Holland, Massimiliano De Pasquale, Jirong Mao, Takanori Sakamoto, Patricia Schady, Stefano Covino, Yi-Zhong Fan, Zhi-Ping Jin, Paolo D'Avanzo, Angelo Antonelli, Valerio D'Elia, Guido Chincarini, Fabrizio Fiore, Shashi Bhushan Pandey, Bethany E. Cobb

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15 Citations (Scopus)

Abstract

We present an analysis of the unusual optical light curve of the gamma-ray burst GRB 081029, a long-soft burst with a redshift of z = 3.8479. We combine X-ray and optical observations from the Swift X-Ray Telescope and the Swift UltraViolet/Optical Telescope with ground-based optical and infrared data obtained using the REM, ROTSE, and CTIO 1.3 m telescopes to construct a detailed data set extending from 86 s to ~100000 s after the BAT trigger. Our data cover a wide energy range from 10 keV to 0.77 eV (1.24 Å-16000 Å). The X-ray afterglow shows a shallow initial decay followed by a rapid decay starting at about 18000 s. The optical and infrared afterglow, however, shows an uncharacteristic rise at about 3000 s that does not correspond to any feature in the X-ray light curve. Our data are not consistent with synchrotron radiation from a jet interacting with an external medium, a two-component jet, or continuous energy injection from the central engine. We find that the optical light curves can be broadly explained by a collision between two ejecta shells within a two-component jet. A growing number of gamma-ray-burst afterglows are consistent with complex jets, which suggests that some (or all) gamma-ray-burst jets are complex and will require detailed modeling to fully understand them.
Original languageEnglish
Pages (from-to)41
Number of pages1
JournalAstrophysical Journal
Volume745
Issue number1
DOIs
Publication statusPublished - 28 Dec 2011

Keywords

  • gamma-ray burst: general, gamma-ray burst: individual: GRB 081029, Astrophysics - High Energy Astrophysical Phenomena

Cite this

Holland, S. T., De Pasquale, M., Mao, J., Sakamoto, T., Schady, P., Covino, S., Fan, Y-Z., Jin, Z-P., D'Avanzo, P., Antonelli, A., D'Elia, V., Chincarini, G., Fiore, F., Bhushan Pandey, S., & Cobb, B. E. (2011). GRB 081029: A Gamma-Ray Burst with a Multi-component Afterglow. Astrophysical Journal, 745(1), 41. https://doi.org/10.1088/0004-637X/745/1/41