GRB 020813

From Wikipedia, the free encyclopedia
Jump to: navigation, search
GRB 020813
Detection
Detection time 13 August 2002
02:44 UTC
Detected by HETE
Duration 25 seconds
Position
Right ascension 19h 46m 38s
Declination −19° 35′ 16″
Redshift z = 1.254
See also: Gamma-ray burst, Category:Gamma-ray bursts

GRB 020813 was a gamma-ray burst (GRB) that was detected on 13 August 2002 at 02:44 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).

Observations[edit]

GRB 020813 was detected on 13 August 2002 02:44 UTC by multiple instruments on the High Energy Transient Explorer. The burst lasted approximately 125 seconds. The initial position was estimated to be at a right ascension of 19h 46m 38s and a declination of −19° 35′ 16″.[1] In less than two hours after the burst had been detected, optical observations of the region were made with the Katzman Automatic Imaging Telescope which reveal the burst's optical afterglow.[2] In the days following the event, observations were made by the Chandra X-ray Observatory, which detected a fading X-ray afterglow.[3] The redshift for this event was approximately z = 1.254.[4]

Supernova relation[edit]

Previous to this burst, there had not yet been any concrete evidence linking gamma-ray bursts to supernovae, though it had long been hypothesized that the two phenomena were results of the same type of event. The spectrum of GRB 011211 was reported to include emission lines associated with the chemical elements magnesium, silicon, sulphur, argon, and calcium, which supported the theory that gamma-ray bursts are preceded by highly massive stars undergoing a supernova collapse.[5] However, these results were considered statistically insignificant and somewhat controversial due to the low resolution of the instruments used.[6] The spectrum of GRB 020813 was also found to display emission lines of elements associated with supernovae, in this case sulphur and silicon.[6] This evidence confirmed the connection between supernovae and gamma-ray bursts.[7][8]

References[edit]

  1. ^ Lamb, Don (13 August 2002). "GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time". GCN Circulars 1471. 
  2. ^ Li, Weidong (13 August 2002). "GRB020813: optical afterglow". GCN Circulars 1473. 
  3. ^ Ricker, George (19 August 2002). "GRB020813: Fading X-ray Afterglow Observed with Chandra". GCN Circulars 1504. 
  4. ^ Price, Paul (13 August 2002). "GRB 020813: Absorption redshift". GCN Circulars 1475. 
  5. ^ Reeves, J. N. et al. (April 2002). "The signature of supernova ejecta in the X-ray afterglow of the γ-ray burst 011211". Nature 416 (6880): 512–515. arXiv:astro-ph/0204075. Bibcode:2002Natur.416..512R. doi:10.1038/416512a. PMID 11932738. 
  6. ^ a b Butler, Nathaniel R. et al. (10 November 2003). "The X-ray Afterglows of GRB 020813 and GRB 021004 with Chandra HETGS: Possible Evidence for a Supernova prior to GRB 020813" (PDF). The Astrophysical Journal 597 (2): 1010–1016. arXiv:astro-ph/0303539. Bibcode:2003ApJ...597.1010B. doi:10.1086/378511. 
  7. ^ "Cosmic Forensics Confirms Gamma-Ray Burst And Supernova Connection" (Press release). NASA. 24 March 2003. Retrieved 23 May 2010. 
  8. ^ Fazekas, Andrew (2 April 2003). "Supernova is 'smoking gun' in gamma-ray-burst whodunit". Astronomy. Retrieved 23 May 2010. 

External links[edit]