| Autor: |
Li, Long, Wang, Xiang-Gao, Zheng, WeiKang, Pozanenko, Alexei S., Filippenko, Alexei V., Qin, Songmei, Wang, Shan-Qin, Jiang, Lu-Yao, Li, Jing, Lin, Da-Bin, Liang, En-Wei, Volnova, Alina A., Elenin, Leonid, Klunko, Evgeny, Inasaridze, Raguli Ya., Kusakin, Anatoly, Lu, Rui-Jing |
| Předmět: |
|
| Zdroj: |
Astrophysical Journal; 9/10/2020, Vol. 900 Issue 2, p1-11, 11p |
| Abstrakt: |
We present very early ground-based optical follow-up observations of gamma-ray burst (GRB) 140423A, which was discovered by the Swift/Burst Alert Telescope (BAT) and by the Fermi/Gamma-Ray Burst Monitor. Its broadband afterglow was monitored by the Swift/X-Ray Telescope and ground-based optical telescopes from T0 + 70.96 s to 4.8 days after the Swift/BAT trigger. This is one more case of a prompt optical emission observation. The temporal and spectral joint fits of the multiwavelength light curves of GRB 140423A reveal that achromatic behavior is consistent with the external shock model, including a transition from a stellar wind to the interstellar medium (ISM) and energy injection. In terms of the optical light curves, there is an onset bump in the early afterglow with a rising index (peaking at s). It then decays with a steep index , and shows a steeper to flatter "transition" with at around T0 + 5000 s. The observed X-ray afterglow reflects achromatic behavior, as does the optical light curve. There is no obvious evolution of the spectral energy distribution between the X-ray and optical afterglows, with an average value of the photon index. This "transition" is consistent with an external shock model having the circumburst medium transition from a wind to the ISM, by introducing a long-lasting energy injection with a Lorentz factor stratification of the ejecta. The best parameters from Monte Carlo Markov Chain fitting are erg, , , , , cm, , , , , and. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
