EDP Sciences
Free access
Volume 464, Number 3, March IV 2007
Page(s) L25 - L27
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20066592

A&A 464, L25-L27 (2007)
DOI: 10.1051/0004-6361:20066592


Near real-time selection of high redshift GRBs with Swift

S. Campana1, G. Tagliaferri1, D. Malesani1, L. Stella1, P. D'Avanzo1, 2, G. Chincarini1, 3, and S. Covino1

1  INAF - Osservatorio Astronomico di Brera, via Bianchi 46, 23807 Merate (Lc), Italy
    e-mail: campana@merate.mi.astro.it
2  Università degli Studi dell'Insubria, Dipartimento di Fisica e Matematica, via Valleggio 11, 22100 Como, Italy
3  University of Milano Bicocca, Department of Physics, Piazza delle Scienze 3, 20126 Milano, Italy

(Received 18 October 2006 / Accepted 12 January 2007)

A good fraction of GRBs detected by Swift have a high redshift (up to z=6.3, so far). Their study allows us to investigate, among other things, cosmic star formation in the early Universe (possibly up to the re-ionization era) and the chemical enrichment of the high-redshift gas. Here we present and discuss a selection procedure that identifies high-redshift ( $z\gtrsim 5$) candidates based only upon the promptly-available information provided by Swift. This method relies upon Galactic extinction, GRB duration, and the absence of an optical counterpart in the UVOT telescope onboard Swift. This tool may provide an extremely effective way to locate high-redshift astrophysical objects and to follow them in the optical/NIR band in near real time.

Key words: gamma rays: bursts -- cosmology: early Universe

© ESO 2007