Title of article :
Optical and near-infrared observations of the GRB020405 afterglow
Author/Authors :
Hjorth، J. نويسنده , , Masetti، N. نويسنده , , Pian، E. نويسنده , , Castro-Tirado، A. J. نويسنده , , Levan، A. نويسنده , , Falomo، R. نويسنده , , Christensen، L. نويسنده , , Palazzi، E. نويسنده , , Simoncelli، A. نويسنده , , Hunt، L. K. نويسنده , , Maiorano، E. نويسنده , , Rol، E. نويسنده , , Savaglio، S. نويسنده , , Delsanti، A. نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2003
Abstract :
We present an analysis of Hubble Space Telescope/WFPC2 images of nine nearby galaxies in Sculptor. We derive their distances from the luminosity of the tip of the red giant branch stars with a typical accuracy of ~12%. Their distances are 4.21 Mpc (Sc 22), 4.92 Mpc (DDO 226), 3.94 Mpc (NGC 253), 3.40 Mpc (KDG 2), 3.34 Mpc (DDO 6), 3.42 Mpc (ESO 540-030), 4.43 Mpc (ESO 245-05), 4.27 Mpc (UGCA 442), and 3.91 Mpc (NGC 7793). The galaxies are concentrated in several spatially separated loose groups around NGC 300, NGC 253, and NGC 7793. The Sculptor galaxy complex together with the CVn I cloud and the Local Group form a 10 Mpc filament, apparently driven by the free Hubble flow.
Keywords :
cosmology , Radiation mechanisms , gamma rays , Identification , line , bursts , Observations , non-thermal
Journal title :
Astronomy and Astrophysics
Journal title :
Astronomy and Astrophysics
