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Are GRB optical afterglows relatively brighter at high z?

High Energy Astrophysical Phenomena 2015-05-13 v1 Cosmology and Nongalactic Astrophysics

Abstract

The redshift distribution of gamma-ray bursts (GRBs) is strongly biased by selection effects. We investigate, via Monte Carlo simulations, one possible selection effect that may be modifying the Swift GRB redshift distribution. We show how telescope response times to acquire a GRB redshift may, via the Malmquist effect and GRB optical afterglow brightness distribution, introduce a bias into the average of the observed redshift distribution. It is difficult to reconcile a recently reported correlated trend between telescope response time and average redshifts unless we employ a redshift-dependent optical afterglow distribution. Simulations of this selection effect suggest that GRB optical afterglows may have been either intrinsically brighter early in the Universe or suffered less local host galaxy extinction.

Keywords

Cite

@article{arxiv.0908.0410,
  title  = {Are GRB optical afterglows relatively brighter at high z?},
  author = {A. Imerito and D. M. Coward and R. R. Burman and D. G. Blair},
  journal= {arXiv preprint arXiv:0908.0410},
  year   = {2015}
}

Comments

5 pages, 3 figures, 1 table

R2 v1 2026-06-21T13:32:11.537Z