A metal rich molecular cloud surrounds GRB 050904 at redshift 6.3

Abstract

GRB050904 is the gamma-ray burst with the highest measured redshift. We performed time resolved X-ray spectroscopy of the late GRB and early afterglow emission. We find robust evidence for a decrease with time of the soft X-ray absorbing column. We model the evolution of the column density due to the flash ionization of the GRB and early afterglow photons. This allows us to constrain the metallicity and geometry of the absorbing cloud. We conclude that the progenitor of GRB050904 was a massive star embedded in a dense metal enriched molecular cloud with Z~0.03 Z_solar. This is the first local measurement of metallicity in the close environment of a GRB and one of the highest redshift metallicity measurements. We also find that the dust associated with the cloud cannot be similar to that of our Galaxy but must be either sizably depleted or dominated by silicate grains. We discuss the implications of these results for GRB progenitors and high redshift star formation.

arXiv comment4 pages, 2 figures. Accepted for publication on Astrophysical Journal Letters

References in corpus (28)

• Discovery of the peculiar supernova 1998bw in the error box of GRB980425
• A very energetic supernova associated with the gamma-ray burst of 29 March 2003
• Spectroscopic Discovery of the Supernova 2003dh Associated with GRB 030329
• The First Stars
• The shock break-out of GRB 060218/SN 2006aj
• Dust Formation in Primordial Type II Supernovae
• Bright X-ray Flares in Gamma-Ray Burst Afterglows
• SN 2003lw and GRB 031203: A Bright Supernova for a Faint Gamma-ray Burst
• Implications for the Cosmic Reionization from the Optical Afterglow Spectrum of the Gamma-Ray Burst 050904 at z = 6.3
• Dust sublimation by GRBs and its implications
• Molecular Gas in the Host Galaxy of a Quasar at Redshift z=6.42
• The Metallicity of High Redshift Galaxies: The Abundance of Zinc in 34 Damped Lyman Alpha Systems from z = 0.7 to 3.4
• The UCSD HIRES/KeckI Damped Lya Abundance Database: II. The Implications
• Massive-Star Supernovae as Major Dust Factories
• High-excitation CO in a quasar host galaxy at z=6.42
• The Giant X-ray Flare of GRB 050502B: Evidence for Late-Time Internal Engine Activity
• Dust Formation in Very Massive Primordial Supernovae
• Dissecting the Circumstellar Environment of Gamma-Ray Burst Progenitors
• Discovery and identification of the very high redshift afterglow of GRB 050904
• GRB 050904 at redshift 6.3: observations of the oldest cosmic explosion after the Big Bang
• VLT observations of the z=6.28 quasar SDSS 1030+0524
• Time-Dependent Photoionization in a Dusty Medium I: Code Description and General Results
• Detection of a very bright optical flare from a gamma-ray burst at redshift 6.29
• Identifying the Environment and Redshift of GRB Afterglows from the Time-Dependence of Their Absorption Spectra
• A flash in the dark: UVES/VLT high resolution spectroscopy of GRB afterglows
• Detection of a huge explosion in the early Universe
• An Energetic Afterglow From A Distant Stellar Explosion
• Outshining the quasars at reionisation: The X-ray spectrum and lightcurve of the redshift 6.29 Gamma-Ray Burst GRB050904

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• Exploration of the high-redshift universe enabled by THESEUS
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