Can a double component outflow explain the X-ray and optical lightcurves of Swift Gamma-Ray Bursts?

DE PASQUALE M., Evans P., Oates S., Page M., Zane S., Schady P., ...Daha Fazla

ADVANCES IN SPACE RESEARCH, cilt.48, sa.8, ss.1411-1414, 2011 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 48 Sayı: 8
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1016/j.asr.2011.06.006
  • Dergi Adı: ADVANCES IN SPACE RESEARCH
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1411-1414
  • Anahtar Kelimeler: Gamma-Ray Bursts, Relativistic outflow, Multi-component outflow, AFTERGLOW LIGHT CURVES, JET BREAKS, THEORETICAL IMPLICATIONS, XRT DATA, BEPPOSAX, CATALOG
  • İstanbul Üniversitesi Adresli: Evet

Özet

An increasing sample of Gamma-Ray Bursts (GRBs) observed by Swift show evidence of 'chromatic breaks', i.e. breaks that are present in the X-ray but not in the optical. We find that in a significant fraction of these ORB afterglows the X-ray and the optical emission cannot be produced by the same component. We propose that these afterglow lightcurves are the result of a two-component jet, in which both components undergo energy injection for the whole observation and the X-ray break is due to a jet break in the narrow outflow. Bursts with chromatic breaks also explain another surprising finding, the paucity of late achromatic breaks. We propose a model that may explain the behaviour of GRB emission in both X-ray and optical bands. This model can be a radical and noteworthy alternative to the current interpretation for the 'canonical' XRT and UVOT lightcurves, and it bears fundamental implications for GRB physics. (C) 2011 COSPAR. Published by Elsevier Ltd. All rights reserved.