GRB 051221A was a gamma ray burst (GRB) that was detected by NASA's Swift Gamma-Ray Burst Mission on December 21, 2005. The coordinates of the burst were α=21h 54m 50.7s, δ=16° 53′ 31.9″, and it lasted about 1.4 seconds.[1] The same satellite discovered X-ray emission from the same object, and the GMOS Instrument on the Gemini Observatory discovered an afterglow in the visible spectrum. This was observed for the next ten days, allowing a redshift of Z = 0.5464 to be determined for the host galaxy.[2]

GRB 051221A
Event typeGamma-ray burst
Datec. 5 billion years ago
(detected 21 December 2005)
Durationc. 1.4 seconds
InstrumentSwift
ConstellationPegasus
Distancec. 5 billion ly
Redshift0.5464
Other designationsGRB 051221, GRB 051221A
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The gamma ray emission from this object is of the variety known as a short-hard burst. The energy emission is consistent with the model of a merger by compact objects. It was the most distant short-hard burst found to that date for which a redshift could be determined.[2] The X-ray light curve showed evidence of three distinct breaks, possibly representing a strong energy injection.[3] The energy may have been injected by a millisecond magnetar. That is, a rapidly rotating pulsar with a strong magnetic field, estimated at 1014 gauss (1010 teslas).[4]

References

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  1. ^ Soderberg, A. M.; et al. (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. S2CID 17155094.
  2. ^ a b Soderberg, Alicia. "An In-Depth Study of the Most Distant Short-Hard Burst". Princeton University. Retrieved 2009-04-16. [dead link]
  3. ^ Burrows, David N.; et al. (2006). "Jet Breaks in Short Gamma-Ray Bursts. II. The Collimated Afterglow of GRB 051221A". The Astrophysical Journal. 653 (1): 468–473. arXiv:astro-ph/0604320. Bibcode:2006ApJ...653..468B. doi:10.1086/508740. S2CID 28202288.
  4. ^ Fan, Yi-Zhong; Xu, Dong (2006). "The X-ray afterglow flat segment in short GRB 051221A: Energy injection from a millisecond magnetar?". Monthly Notices of the Royal Astronomical Society: Letters. 372 (1): L19–L22. arXiv:astro-ph/0605445. Bibcode:2006MNRAS.372L..19F. doi:10.1111/j.1745-3933.2006.00217.x. S2CID 16922743.