Unveiling the Multifaceted GRB 200613A: Prompt Emission Dynamics, Afterglow Evolution, and the Host Galaxy's Properties

• Published in: arXiv.org 2024-07
• Main Authors: Shao-Yu, Fu, Xu, Dong, Wei-Hua, Lei, Antonio de Ugarte Postigo, Kann, D Alexander, Thöne, Christina C, José Feliciano Agüí Fernández, Shuang-Xi, Yi, Xie, Wei, Zou, Yuan-Chuan, Liu, Xing, Shuai-Qing Jiang, Tian-Hua, Lu, An, Jie, Zi-Pei Zhu, Zheng, Jie, Qing-Wen Tang, Peng-Wei, Zhao, Li-Ping, Xin, Jian-Yan, Wei
• Format: Article
• Language: English
• Subjects: Afterglows; Astronomical models; Bayesian analysis; Blackbody; Ejecta; Emission; Galactic evolution; Galaxy distribution; Gamma ray bursts; Interstellar matter; Light curve; Neutrinos; Optical properties; Spectral energy distribution; Spectrum analysis; Star & galaxy formation; Star formation rate
• ISSN: 2331-8422

We present our optical observations and multi-wavelength analysis of the GRB\,200613A detected by \texttt{Fermi} satellite. Time-resolved spectral analysis of the prompt \(\gamma\)-ray emission was conducted utilizing the Bayesian block method to determine statistically optimal time bins. Based on the Bayesian Information Criterion (BIC), the data generally favor the Band+Blackbody (short as BB) model. We speculate that the main Band component comes from the Blandford-Znajek mechanism, while the additional BB component comes from the neutrino annihilation process. The BB component becomes significant for a low-spin, high-accretion rate black hole central engine, as evidenced by our model comparison with the data. The afterglow light curve exhibits typical power-law decay, and its behavior can be explained by the collision between the ejecta and constant interstellar medium (ISM). Model fitting yields the following parameters: \(E_{K,iso} = (2.04^{+11.8}_{-1.50})\times 10^{53}\) erg, \(\Gamma_0=354^{+578}_{-217}\), \(p=2.09^{+0.02}_{-0.03}\), \(n_{18}=(2.04^{+9.71}_{-1.87})\times 10^{2}\) cm\(^{-3}\), \(\theta_j=24.0^{+6.50}_{-5.54}\) degree, \(\epsilon_e=1.66^{+4.09}_{-1.39})\times 10^{-1}\) and \(\epsilon_B=(7.76^{+48.5}_{-5.9})\times 10^{-6}\). In addition, we employed the public Python package \texttt{Prospector} perform a spectral energy distribution (SED) modeling of the host galaxy. The results suggest that the host galaxy is a massive galaxy (\(\log(M_\ast / M_\odot)=11.75^{+0.10}_{-0.09}\)) with moderate star formation rate (\(\mbox{SFR}=22.58^{+13.63}_{-7.22} M_{\odot}\)/yr). This SFR is consistent with the SFR of \(\sim 34.2 M_{\odot}\) yr\(^{-1}\) derived from the [OII] emission line in the observed spectrum.