The most distant cosmological explosion

Poonam Chandra, Dale A. Frail, Derek Fox, S. R. Kulkarni, Edo Berger, S. Bradley Cenko, Douglas C.J. Bock, Fiona Harrison, Mansi Kasliwal

Research output: Chapter in Book/Report/Conference proceedingConference contribution


At a redshift of 8.3 GRB 090423 marks the highest known redshift object in the Universe. By combining our radio measurements with existing X-ray and infrared observations, we estimated the kinetic energy of the afterglow, the geometry of the outflow and the density of the circumburst medium. Our best fit model is a quasi-spherical, high-energy explosion in a low, constant-density medium. We compare the properties of GRB 090423 with a sample of GRBs at moderate redshifts. We find that the high energy and afterglow properties of GRB 090423 are not sufficiently different from other GRBs to suggest a different kind of progenitor, such as a Population III star. However, we argue that it is not clear that the afterglow properties alone can provide convincing identification of Population III progenitors. We suggest that the millimeter and centimeter radio detections of GRB 090423 at early times contained emission from a reverse shock component. This has important implications for the detection of high redshift GRBs by the next generation of radio facilities.

Original languageEnglish (US)
Title of host publication25th Texas Symposium on Relativistic Astrophysics, TEXAS 2010
Number of pages8
StatePublished - 2011
Event25th Texas Symposium on Relativistic Astrophysics, TEXAS 2010 - Heidelberg, Germany
Duration: Dec 6 2010Dec 10 2010

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


Other25th Texas Symposium on Relativistic Astrophysics, TEXAS 2010

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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