GRB 011211

GRB 011211 was a gamma-ray burst (GRB) detected on December 11, 2001. 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).

GRB 011211

Event type	Gamma-ray burst
Constellation	Crater
Right ascension	168h 49m 4.8s
Declination	−21° 55′ 44.4″[1]
Redshift	2.14 ±0.01, 2.14
Total energy output	5×1052 ergs
Other designations	GRB 011211

Observations

GRB 011211 was detected by the Italian–Dutch X-ray astronomy satellite BeppoSAX on 11 December 2001 at 19:09 UTC.^[2] The burst lasted 270 seconds, making it the longest burst that had ever been detected by BeppoSAX up to that point.^[3] A spectrum recorded by the Yepun telescope indicated a redshift of z = 2.14.^[4]

Supernova relation

A team of researchers at the University of Leicester conducted an analysis of the burst's X-ray afterglow with the XMM-Newton observatory. They found evidence for emission lines of magnesium, silicon, sulphur, and various other chemical elements. This was the first detection of these elements in the spectrum of a GRB.^[5] These observations provided strong evidence for a relation between gamma-ray bursts and supernova.^[3] However, other astronomers pointed out flaws in the methodology of the Leicester research team, such as the data reduction methods,^[6] the low statistical significance of the emission lines,^[7] and the low spectral resolution of the instrument used.^[8] Despite a follow-up paper from the Leicester team to address these concerns,^[9] the findings remained controversial, and GRB 020813 was given the distinction of being the first burst with direct evidence of a supernova relation.^[10][11]

Host galaxy

Optical, infrared, and X-ray observations taken by the Hubble Space Telescope between 14 and 59 days after the burst's detection revealed a blue galaxy with an apparent magnitude of 24.95 ± 0.11.^[12] Like several other gamma-ray burst hosts, Lyman alpha emission was detected from this galaxy, supporting the theory that the progenitors of gamma-ray burst tend to be metal-poor.^[13]