Astronomy:GRB 070714B

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GRB 070714B
Right ascension 03h 51m 22.29s
Declination+28° 17′ 52.2″
Total energy output1.2×1051 ergs

GRB 070714B was a gamma-ray burst (GRB) that was detected on 14 July 2007 at 04:59 UTC. A gamma-ray burst is a highly luminous flash associated with an explosion in a distant galaxy and producing gamma rays, the most energetic form of electromagnetic radiation, and often followed by a longer-lived "afterglow" emitted at longer wavelengths (X-ray, ultraviolet, optical, infrared, and radio).

At a total duration of only 3 seconds, GRB 070714B was classified as a short burst, a subclass of GRBs which is believed to be caused by the merger of two neutron stars. GRB 070714B had a redshift of z = 0.92, corresponding to a distance of about 7.4 billion light years, making it the most distant short burst detected as of 2007.

Observations

GRB 070714B was detected by the Swift Gamma-Ray Burst Mission satellite on 14 July 2007 at 04:59 UTC. The burst lasted only 3 seconds and reached its peak intensity 0.2 seconds after the initial detection.[1] The optical afterglow was detected by the Liverpool Telescope[2] and the William Herschel Telescope.[3]

Distance record

Spectroscopy of the optical afterglow and the burst's host galaxy revealed a single emission line of oxygen at a redshift of z = 0.92.[4] This corresponds to a distance of 7.4 billion light years, making it the oldest and most distant short burst ever detected.[5] The previous record holder had been GRB 051221A at a redshift of z = 0.546.[4][6] At a redshift of z = 0.92, the total energy released by GRB 070714B (assuming isotropic emission) was approximately 1.2×1051 ergs, which is several orders of magnitude higher than short-duration bursts with a redshift less than z = 0.5, but still significantly smaller than typical long-duration bursts.[7]

Notes

  1. Barthelmy, Scott (14 July 2007). "GRB 070714: Swift detection of a bright burst, possibly short". GCN Circulars 6620: 1. Bibcode2007GCN..6620....1R. http://gcn.gsfc.nasa.gov/gcn3/6620.gcn3. 
  2. Melandri, Andrea (14 July 2007). "GRB 070714 : Liverpool Telescope optical counterpart?". GCN Circulars 6621: 1. Bibcode2007GCN..6621....1M. http://gcn.gsfc.nasa.gov/gcn3/6621.gcn3. 
  3. Levan, Andrew (14 July 2007). "GRB 070714B: confirmation of optical afterglow". GCN Circulars 6630: 1. http://gcn.gsfc.nasa.gov/gcn3/6630.gcn3. 
  4. 4.0 4.1 Graham, J. F. (3 June 2009). "GRB 070714B—Discovery of the Highest Spectroscopically Confirmed Short Burst Redshift". The Astrophysical Journal 698 (2): 1620–1629. doi:10.1088/0004-637X/698/2/1620. Bibcode2009ApJ...698.1620G. 
  5. Naeye, Robert (8 January 2008). "NASA and Gemini Probe Mysterious Distant Explosion". NASA Goddard Space Flight Center. http://www.nasa.gov/centers/goddard/news/topstory/2007/gemini_explosion.html. Retrieved 14 July 2010. 
  6. Soderberg, A. M. (10 October 2006). "The Afterglow, Energetics, and Host Galaxy of the Short-Hard Gamma-Ray Burst 051221a". The Astrophysical Journal 650 (1): 261–271. doi:10.1086/506429. Bibcode2006ApJ...650..261S. 
  7. Cenko, S. Bradley (7 February 2008). "GRBs 070429B and 070714B: The High End of the Short-Duration Gamma-Ray Burst Redshift Distribution". The Astrophysical Journal. Bibcode2008arXiv0802.0874C.