GRB 070714B
| Event type | Gamma-ray burst  |
|---|---|
| Constellation | Taurus |
| Right ascension | 03h 51m 22.29s |
| Declination | +28° 17′ 52.2″ |
| Distance | 7,400,000,000 ly (2.3×109 pc) |
| Total energy output | 1.2×1051 ergs |
| Other designations | GRB 070714B |
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
[edit]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
[edit]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
[edit]- ^ Barthelmy, Scott (14 July 2007). "GRB 070714: Swift detection of a bright burst, possibly short". GCN Circulars. 6620: 1. Bibcode:2007GCN..6620....1R.
- ^ Melandri, Andrea (14 July 2007). "GRB 070714 : Liverpool Telescope optical counterpart?". GCN Circulars. 6621: 1. Bibcode:2007GCN..6621....1M.
- ^ Levan, Andrew (14 July 2007). "GRB 070714B: confirmation of optical afterglow". GCN Circulars. 6630: 1.
- ^ a b Graham, J. F.; et al. (3 June 2009). "GRB 070714B—Discovery of the Highest Spectroscopically Confirmed Short Burst Redshift". The Astrophysical Journal. 698 (2): 1620–1629. arXiv:0808.2610. Bibcode:2009ApJ...698.1620G. doi:10.1088/0004-637X/698/2/1620.
- ^ Naeye, Robert (8 January 2008). "NASA and Gemini Probe Mysterious Distant Explosion". NASA Goddard Space Flight Center. Retrieved 14 July 2010.
- ^ Soderberg, A. M.; et al. (10 October 2006). "The Afterglow, Energetics, and Host Galaxy of the Short-Hard Gamma-Ray Burst 051221a". The Astrophysical Journal. 650 (1): 261–271. arXiv:astro-ph/0601455. Bibcode:2006ApJ...650..261S. doi:10.1086/506429.
- ^ Cenko, S. Bradley; et al. (7 February 2008). "GRBs 070429B and 070714B: The High End of the Short-Duration Gamma-Ray Burst Redshift Distribution". The Astrophysical Journal. arXiv:0802.0874. Bibcode:2008arXiv0802.0874C.
