Spectral Evolution of the GRB 030329 Afterglow: Detection of the Supernova Nebular Phase Emissions
| Autor: | Masanori Iye, Yuji Shirasaki, Youichi Ohyama, Wako Aoki, Jun-ichi Watanabe, Kentaro Aoki, Toru Yamada, Y. Urata, Ryusuke Ogasawara, Ken'ichi Torii, Atsumasa Yoshida, Toru Tamagawa, Yulei Qiu, Yoshihiko Mizumoto, Koji S. Kawabata, Tomonori Totani, Junichi Noumaru, Yutaka Komiyama, Tadafumi Takata, Naoto Kobayashi, T. Sakamoto, Kazuhiro Sekiguchi, George Kosugi, Nobuyuki Kawai |
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| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
Physics
gamma rays: bursts Astrophysics::High Energy Astrophysical Phenomena Astronomy Astronomy and Astrophysics stars: supernovae: individual (SN 2003dh) Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics cosmology: early universe Light curve Galaxy Afterglow GRB 970228 Supernova Space and Planetary Science GRB 030329 Astrophysics::Solar and Stellar Astrophysics gamma rays: individual (GRB 030329) Emission spectrum Astrophysics::Earth and Planetary Astrophysics Gamma-ray burst Astrophysics::Galaxy Astrophysics gamma rays: observations |
| Zdroj: | Publications of the Astronomical Society of Japan. 56:61-68 |
| Popis: | GRB 030329 is the first Gamma-ray burst event for which a connection with a supernova (SN 2003dh) has been confirmed spectroscopically in its early phase. We present optical spectroscopy of this object 40 and 85 days after the burst (35 and 73 rest-frame days, respectively) obtained with the Subaru 8.2-m telescope. After subtracting the host galaxy template spectrum, the second-epoch spectrum shows nebular-phase emission lines emerging from the dominated photospheric-phase spectrum. The transition from the photospheric phase to the nebular phase has just started, or was slowly progressing at the time of our second-epoch observations. Our spectral analysis of the nebular-phase emission lines suggests that the explosion of the progenitor of the GRB 030329 was aspherical, and that the axis of an asphericity is well aligned to both the GRB relativistic jet and our line of sight. Although the decay index and the color evolution in the rest frame during our two epochs are very consistent with those of the Type Ic supernovae SN 1998bw and SN 1997ef, the nebular-phase lines emerged slightly earlier than in the case of these supernovae. These results infer that the most important factor that distinguishes SNe with GRB from SNe without GRB is the scale of the jet activity, or a viewing-angle effect, or both of them. |
| Databáze: | OpenAIRE |
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