Multi-wavelength study of the luminous GRB 210619B observed with Fermi and ASIM
| Autor: | Caballero-García, M. D., Gupta, Rahul, Pandey, S. B., Oates, S. R., Marisaldi, M., Ramsli, A., Hu, Y. -D., Castro-Tirado, A. J., Sánchez-Ramírez, R., Connell, P. H., Christiansen, F., Ror, A. Kumar, Aryan, A., Bai, J. -M., Castro-Tirado, M. A., Fan, Y. -F., Fernández-García, E., Kumar, A., Lindanger, A., Mezentsev, A., Navarro-González, J., Neubert, T., Østgaard, N., Pérez-García, I., Reglero, V., Sarria, D., Sun, T. R., Xiong, D. -R., Yang, J., Yang, Y. -H., Zhang, B. -B. |
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| Rok vydání: | 2022 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stac3629 |
| Popis: | We report on detailed multi-wavelength observations and analysis of the very bright and long GRB 210619B, detected by the Atmosphere-Space Interactions Monitor (ASIM) installed on the International Space Station (ISS) and the Gamma-ray Burst Monitor (GBM) on-board the Fermi mission. Our main goal is to understand the radiation mechanisms and jet composition of GRB 210619B. With a measured redshift of $z$ = 1.937, we find that GRB 210619B falls within the 10 most luminous bursts observed by Fermi so far. The energy-resolved prompt emission light curve of GRB 210619B exhibits an extremely bright hard emission pulse followed by softer/longer emission pulses. The low-energy photon indices ($\alpha_{\rm pt}$) values obtained using the time-resolved spectral analysis of the burst suggest a transition between the thermal (during harder pulse) to non-thermal (during softer pulse) outflow. We examine the correlation between spectral parameters and find that both peak energy and $\alpha_{\rm pt}$ exhibit the flux tracking pattern. The late time broadband photometric dataset can be explained within the framework of the external forward shock model with $\nu_m$ $< \nu_c$ $< \nu_{x}$ (where $\nu_m$, $\nu_c$, and $\nu_{x}$ are the synchrotron peak, cooling-break, and X-ray frequencies, respectively) spectral regime supporting a rarely observed hard electron energy index ($p<$ 2). We find moderate values of host extinction of E(B-V) = 0.14 $\pm$ 0.01 mag for the Small Magellanic Cloud (SMC) extinction law. In addition, we also report late-time optical observations with the 10.4 m GTC placing deep upper limits for the host galaxy ($z$=1.937), favouring a faint, dwarf host for the burst. Comment: 24 pages, 18 figures, 10 tables, accepted for publication in MNRAS |
| Databáze: | arXiv |
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