X GRB 060904 A Swift GRB To O
プロンプトから初期X線残光に続くスペクトル変化 - GRB 060904 A : Swift と すざく衛星による観測 - 米徳 大輔、 田辺 幸子、 村上 敏夫 (金沢大学) 「すざく」 GRB To. O team Y. Aoyama, T. Kidamura, H. Kodaira, S. Okuno, S. Yokota, S. Yoshinari, M. S. Tashiro, K. Abe, K. Onda, Y. Urata, A. Yoshida, K. Yamaoka, N. Ishikawa, Y. E. Nakagawa, S. Sugita, N. Kawai, T. Ishimura, M. Kawahara, T. Shimokawabe, K. Kinugasa, T. Kohmura, Y. Ueda, S. Eguchi, K. Kubota, M. Yamauchi, E. Sonoda, S. Maeno, K. T. Takahashi, Nakazawa, T. Tamagawa, M. Suzuki, & K. Torii L. Angelini, S. Barthelmy, L. J. Kaluzienski, R. L. Kelley, J. N. Reeves, N. Gehrels, J. Nousek, & G. Ricker yonetoku@astro. s. kanazawa-u. ac. jp
X線残光の振る舞い Nousek et al. 2005 Very Steep 3 < α 1 < 5 Shallow Decay 0. 5 < α 2 < 1. 0 Classical (Typical) Decay -α 4 tbreak, 3 Swift すざく t 1 < α 3 < 1. 5 Jet Break α 4 > 2 ● Very Steep, Shallow Decay 部分の振る舞い prompt → afterglow の移行に関する情報 ● Very Steep Phase がプロンプトの減光部分ならば、 internal shock のダイナミクスを知る手がかり ● Shallow → Classical Decay afterglow の時間発展を精度良く追いかける
Flux [erg/cm 2/s] lightcurve XRT/Swift すざく Photon Index ベキ = -5. 3 photon index NH [1022 cm-2] absorption (NH) 1000 Time [sec] 104 105
afterglow のスペクトル fast cooling ν 2 ν 1/3 F∝ ν-1/2 E-1. 5 ν-p/2 E-2. 25 slow cooling ν 2 ν 1/3 F∝ ν-(p-1)/2 E-1. 75 ν-p/2 E-2. 25 Piran (1999)
Ryde (2005)
Konus の観測では ・ 20 ke. V – 2 Me. V の範囲で Band Model で良く合う。 ・ α = 1. 00 +0. 23 , - 0. 17 β = 2. 57 +0. 37 , - 1. 00 Ep = 163± 31 ke. V GCN Circular #5518 S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and T. Cline on behalf of the Konus-Wind team report: The most intense part of the long GRB 060904 A (Swift-BAT trigger #227996; Grupe et al. , GCN 5502; Krimm et al. , GCN 5516) triggered Konus-Wind at T 0=3853. 821 s UT (01: 04: 13. 821). As observed by Konus-Wind the burst emission started at T-T 0 ~-56 s, peaked at T-T 0 ~0 s, and ended at T-T 0 ~26 s, so the total burst duration is ~80 s. The burst fluence is 1. 59(-0. 21, +0. 40)x 10^-5 erg/cm 2, and the 256 -ms peak flux measured from T 0 -0. 128 s 1. 38(-0. 33, +0. 46)x 10^-6 erg/cm 2/s (both in the 20 ke. V - 2 Me. V energy range). The spectrum of the main pulse (from T 0 to T 0+16. 64 s) is well fitted (in the 20 ke. V - 2 Me. V range) by GRBM (Band) model for which: the low-energy photon index is alpha = -1. 00(-0. 17, +0. 23), the high energy photon index beta = -2. 57(-1. 00, 0. 37), the break energy E 0 = 163 (-54, +65) ke. V (chi 2 = 40/61 dof). The peak energy Ep = 163 +/- 31 ke. V. All the quoted errors are at the 90% confidence level.
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