Authors:
Klose, S; Stecklum, B; Masetti, N; Pian, E; Palazzi, E; Henden, AA; Hartmann, DH; Fischer, O; Gorosabel, J; Sanchez-Fernandez, C; Butler, D; Ott, T; Hippler, S; Kasper, M; Weiss, R; Castro-Tirado, A; Greiner, J; Bartolini, C; Guarnieri, A; Piccioni, A; Benetti, S; Ghinassi, F; Magazzu, A; Hurley, K; Cline, T; Trombka, J; McClanahan, T; Starr, R; Goldstein, J; Gold, R; Mazets, E; Golenetskii, S; Noeske, K; Papaderos, P; Vreeswijk, PM; Tanvir, N; Oscoz, A; Munoz, JA; Ceron, JMC
Abstract:
We report near-infrared and optical follow-up observations of the afterglow of the GRB 000418 starting 2.5 days after the occurrence of the burst and extending over nearly 7 weeks. GRB 000418 represents the second case for which the afterglow was initially identified by observations in the near-infrared. During the first 10 days its R-band afterglow was well characterized by a single power-law decay with a slope of 0.86. However, at later times the temporal evolution of the afterglow flattens with respect to a simple power-law decay. Attributing this to an underlying host galaxy, we find its magnitude to be R = 23.9 and an intrinsic afterglow decay slope of 1.22. The afterglow was very red with R-K approximate to 4 mag. The observations can be explained by an adiabatic, spherical fireball solution and a heavy reddening due to dust extinction in the host galaxy. This supports the picture that (long) bursts are associated with events in star-forming regions.
URL:
https://ui.adsabs.harvard.edu/#abs/2000ApJ...545..271K/abstract