TY - JOUR
T1 - Multiple-component analysis of the time-resolved spectra of GRB 041006
T2 - A clue to the nature of the underlying soft component of GRBs
AU - Shirasaki, Yuji
AU - Yoshida, Atsumasa
AU - Kawai, Nobuyuki
AU - Tamagawa, Toru
AU - Sakamoto, Takanori
AU - Suzuki, Motoko
AU - Nakagawa, Yujin
AU - Kobayashi, Akina
AU - Sugita, Satoshi
AU - Takahashi, Ichiro
AU - Arimoto, Makoto
AU - Shimokawabe, Takashi
AU - Pazmino, Nicolas Vasquez
AU - Ishimura, Takuto
AU - Sato, Rie
AU - Matsuoka, Masaru
AU - Fenimore, Edward E.
AU - Galassi, Mark
AU - Lamb, Donald Q.
AU - Graziani, Carlo
AU - Donaghy, Timothy Q.
AU - Atteia, Jean Luc
AU - Pelangeon, Alexandre
AU - Vanderspek, Roland
AU - Crew, Geoffrey B.
AU - Doty, John P.
AU - Villasenor, Joel
AU - Paigozhin, Gregory
AU - Butler, Nat
AU - Ricker, George R.
AU - Hurley, Kevin
AU - Woosley, Stanford E.
AU - Pizzichini, Graziella
PY - 2008
Y1 - 2008
N2 - GRB 041006 was detected by HETE-2 on 2004 October 06. The light curves in four different energy bands display different features. At higher energy bands several peaks are seen in the light curve, while at lower energy bands a single broader bump dominates. It is expected that these different features are the result of a mixture of several components, each of which has different energetics and variability. We analyzed the time-resolved spectra, which were resolved into several components. These components can be classified into two distinct classes. One is a component that has an exponential decay of E p with a characteristic timescale shorter than ∼ 30s; its spectrum is well represented by a broken power-law function, which is frequently observed in many prompt GRB emissions, so it should have an internal-shock origin. Another is a component whose Ep is almost unchanged with a characteristic timescale longer than ∼ 60s, and shows a very soft emission and slower variability. The spectrum is characterized by either a broken power law or a black-body spectrum. By assuming that the soft component is a thermal emission, the radiation radius is initially 4.4 x 106km, which is a typical radius of a blue supergiant, and its expansion velocity is 2.4 x 10 5km s-1 in the source frame.
AB - GRB 041006 was detected by HETE-2 on 2004 October 06. The light curves in four different energy bands display different features. At higher energy bands several peaks are seen in the light curve, while at lower energy bands a single broader bump dominates. It is expected that these different features are the result of a mixture of several components, each of which has different energetics and variability. We analyzed the time-resolved spectra, which were resolved into several components. These components can be classified into two distinct classes. One is a component that has an exponential decay of E p with a characteristic timescale shorter than ∼ 30s; its spectrum is well represented by a broken power-law function, which is frequently observed in many prompt GRB emissions, so it should have an internal-shock origin. Another is a component whose Ep is almost unchanged with a characteristic timescale longer than ∼ 60s, and shows a very soft emission and slower variability. The spectrum is characterized by either a broken power law or a black-body spectrum. By assuming that the soft component is a thermal emission, the radiation radius is initially 4.4 x 106km, which is a typical radius of a blue supergiant, and its expansion velocity is 2.4 x 10 5km s-1 in the source frame.
KW - Gamma-rays: Bursts
KW - X-rays: individual (GRB 041006)
KW - X-rays: nursts
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U2 - 10.1093/pasj/60.4.919
DO - 10.1093/pasj/60.4.919
M3 - Article
AN - SCOPUS:52049100870
SN - 0004-6264
VL - 60
SP - 919
EP - 931
JO - Publications of the Astronomical Society of Japan
JF - Publications of the Astronomical Society of Japan
IS - 4
ER -