The emission region of gamma-ray bursts (GRBs) is poorly constrained. The uncertainty on the size of the dissipation site spans over 4 orders of magnitude (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 similar to 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 (E-iso asymptotic to 3x10(54) erg) and the spectral cutoff at 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 700 < 1160 and R-gamma similar to 4.5x10(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.

Constraints on the Physics of the Prompt Emission from Distant and Energetic Gamma-Ray Burst GRB 220101A

Anastasia Tsvetkova;
2022-01-01

Abstract

The emission region of gamma-ray bursts (GRBs) is poorly constrained. The uncertainty on the size of the dissipation site spans over 4 orders of magnitude (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 similar to 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 (E-iso asymptotic to 3x10(54) erg) and the spectral cutoff at 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 700 < 1160 and R-gamma similar to 4.5x10(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.
File in questo prodotto:
File Dimensione Formato  
2022_Mei_ApJ_941_82.pdf

accesso aperto

Descrizione: Articolo principale
Tipologia: versione editoriale (VoR)
Dimensione 1.4 MB
Formato Adobe PDF
1.4 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11584/369683
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 6
  • ???jsp.display-item.citation.isi??? 7
social impact