Bibcode
Castro Cerón, J. M.; Castro-Tirado, A. J.; Gorosabel, J.; Hjorth, J.; Fynbo, J. U.; Jensen, B. L.; Pedersen, H.; Andersen, M. I.; López-Corredoira, M.; Suárez, O.; Grosdidier, Y.; Casares, J.; Pérez-Ramírez, D.; Milvang-Jensen, B.; Mallén-Ornelas, G.; Fruchter, A.; Greiner, J.; Pian, E.; Vreeswijk, P. M.; Barthelmy, S. D.; Cline, T.; Frontera, F.; Kaper, L.; Klose, S.; Kouveliotou, C.; Hartmann, D. H.; Hurley, K.; Masetti, N.; Mazets, E.; Palazzi, E.; Park, H. S.; Rol, E.; Salamanca, I.; Tanvir, N.; Trombka, J. I.; Wijers, R. A. M. J.; Williams, G. G.; van den Heuvel, E.
Referencia bibliográfica
Astronomy and Astrophysics, v.393, p.445-451 (2002)
Fecha de publicación:
10
2002
Revista
Número de citas
10
Número de citas referidas
5
Descripción
We present optical follow up observations of the long GRB
001007 between 6.14 hours and ~468 days after the event. An
unusually bright optical afterglow (OA) was seen to decline following a
steep power law decay with index α = -2.03 ± 0.11, possibly
indicating a break in the light curve at t - t0 < 3.5
days, as found in other bursts. Upper limits imposed by the LOTIS
alerting system 6.14 hours after the gamma ray event provide tentative
(1.2σ) evidence for a break in the optical light curve. The
spectral index β of the OA yields -1.24 ± 0.57. These values
may be explained both by several fireball jet models and by the
cannonball model. Fireball spherical expansion models are not favoured.
Late epoch deep imaging revealed the presence of a complex host galaxy
system, composed of at least two objects located 1.2 arcsec (1.7σ)
and 1.9 arcsec (2.7σ) from the afterglow position. Based on
observations collected: at the European Southern Observatory, in La
Silla and Paranal (Chile), ESO Large Programmes 165.H-0464(G),
165.H-0464(I) and 265.D-5742(A), granted to the GRACE Team; with the
Livermore Optical Transient Imaging System's 0.11 m telephoto lenses, at
the Lawrence Livermore National Laboratory, in California (USA); with
the Instituto de Astrofísica de Canarias's 0.82 m telescope, at
the Observatorio del Teide, in the island of Tenerife (Spain); with the
Danish 1.54 m telescope, at the European Southern Observatory, in La
Silla (Chile); and with the Nordic Optical Telescope, operated on the
island of La Palma jointly by Denmark, Finland, Iceland, Norway, and
Sweden, in the Spanish Observatorio del Roque de los Muchachos, of the
Instituto de Astrofísica de Canarias.