Page, K. L.K. L.PageBarthelmy, S. D.S. D.BarthelmyBeardmore, A. P.A. P.BeardmoreGiommi, PaoloPaoloGiommi2020-09-172020-09-172006-05-01https://hdl.handle.net/20.500.13025/472GAMMA-RAY BURSTS IN THE SWIFT ERA Sixteenth Maryland Astrophysics Conference. AIP Conference Proceedings, Volume 836, pp. 321-324 (2006).GRBs 050223 and 050911 were discovered by the Swift Burst Alert Telescope (BAT) on 23rd February and 11th September 2005 respectively. The observation of GRB 050223 showed a faint, fading X-ray source, which was identified as the afterglow; GRB 050911, however, was not detected, making any X-ray afterglow extremely faint. The faintness of the afterglow of GRB 050223 could be explained by a large opening or viewing angle, or by the burst being at high redshift. The non-detection of GRB 050911 may indicate the burst occurred in a low-density environment, or, alternatively, was due to a compact object merger, in spite of the apparent long duration of the burst.10.1063/1.2207912http://adsabs.harvard.edu/abs/2006AIPC..836..321P2006AIPC..836..321P