The optical afterglow and host galaxy of GRB 000926.

• Main Authors: Fynbo, J.U., Gorosabel, J., Dall, T.H., Hjorth,, J., Pedersen, H., Andersen, M.I., Møller, P., Holland, S., Smail, I., Kobayashi, N., Roland, E., Vreeswijk, P., Burud, I., Jensen , B.L., Thomsen , B., Henden, A., Vrba , F., Canzian, B., Castro Cerón, J.M., Castro-Tirado, A.J., Cline, T., Goto, M., Greiner, J., Hanski, M.T., Hurley, K., Lund, N., Pursimo, T., Østensen, R., Solheim, J., Tanvir , N., Terada , H.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: EDP Sciences 2001
• Subjects: Cosmology; Observations; Gamma rays; Bursts; Norway; Observatorio; Iceland
• Online Access: http://dro.dur.ac.uk/10874/; http://dro.dur.ac.uk/10874/1/10874.pdf; https://doi.org/10.1051/0004-6361:20010531

We present the discovery of the Optical Transient (OT) of the long-duration gamma-ray burst GRB 000926. The optical transient was detected independently with the Nordic Optical Telescope and at Calar Alto 22.2 hours after the burst. At this time the magnitude of the transient was R = 19.36. The transient faded with a decay slope of about 1.7 during the first two days after which the slope increased abruptly (within a few hours) to about 2.4. The light-curve started to flatten off after about a week indicating the presence of an underlying extended object. This object was detected in a deep image obtained one month after the GRB at R=23.87+/-0.15 and consists of several compact knots within about 5 arcsec. One of the knots is spatially coincident with the position of the OT and hence most likely belongs to the host galaxy. Higher resolution imaging is needed to resolve whether all the compact knots belong to the host galaxy or to several independent objects. In a separate paper we present a discussion of the optical spectrum of the OT, and its inferred redshift (Møller et al., in prep.). Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden. Based on observations made at the 2.2-m telescope of the German-Spanish Calar Alto Observatory. Based on observations made with the Isaac Newton Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.