| Title: |
Constrains on the physics of the prompt emission from a distant and energetic gamma-ray burst GRB 220101A |
| Authors: |
Mei, Alessio, Oganesyan, Gor, Tsvetkova, Anastasia, Ravasio, Maria Edvige, Banerjee, Biswajit, Brighenti, Francesco, Ronchini, Samuele, Branchesi, Marica, Frederiks, Dmitry |
| Publication Year: |
2022 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - High Energy Astrophysical Phenomena |
| More Details: |
The emission region of $\rm \gamma$-ray bursts (GRBs) is poorly constrained. The uncertainty on the size of the dissipation site spans over 4 orders of magnitude ($\rm 10^{12}-10^{17}$ cm) depending on the unknown energy composition of the GRB jets. The joint multi-band analysis from soft X-rays to high energies (up to $\rm \sim$ 1 GeV) of one of the most energetic and distant GRB 220101A (z = 4.618) allows us for an accurate distinction between prompt and early afterglow emissions. The enormous amount of energy released by GRB 220101A ($\rm E_{iso} \approx 3 \times10^{54}$ erg) and the spectral cutoff at $\rm E_{cutoff} = 85_{-26}^{+16}$ MeV observed in the prompt emission spectrum constrains the parameter space of GRB dissipation site. We put stringent constraints on the prompt emission site, requiring $\rm 700<\Gamma_0<1160 $ and $\rm R_\gamma \sim 4.5 \times 10^{13}$ cm. Our findings further highlights the difficulty of finding a simple self consistent picture in the electron-synchrotron scenario, favoring instead a proton-synchrotron model, which is also consistent with the observed spectral shape. Deeper measurements of the time variability of GRBs together with accurate high-energy observations (MeV-GeV) would unveil the nature of the prompt emission.
Comment: 16 pages, 7 figures. Accepted for ApJ publication |
| Document Type: |
Working Paper |
| DOI: |
10.3847/1538-4357/aca091 |
| Access URL: |
http://arxiv.org/abs/2203.04971 |
| Accession Number: |
edsarx.2203.04971 |
| Database: |
arXiv |
