From precursor to afterglow: The complex evolution of GRB 210312B

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F25%3A00636816" target="_blank" >RIV/67985815:_____/25:00636816 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/25:00636816 RIV/68407700:21230/25:00383956

Výsledek na webu

<a href="https://hdl.handle.net/11104/0367889" target="_blank" >https://hdl.handle.net/11104/0367889</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202453636" target="_blank" >10.1051/0004-6361/202453636</a>

Jazyk výsledku

angličtina

Název v původním jazyce

From precursor to afterglow: The complex evolution of GRB 210312B

Popis výsledku v původním jazyce

Context. Long gamma-ray bursts (GRBs) are characterized by a brief gamma-ray flash followed by a longer-lasting multiwavelength afterglow. The basic mechanism is largely understood, and the early afterglow evolution often shows complex features that provide crucial insights into the transition between prompt and afterglow phases. Aims. We present a detailed analysis of GRB 210312B, detected by INTEGRAL, which exhibits both a precursor and a complex optical afterglow evolution. Through careful modeling using Markov chain Monte Carlo methods, we disentangled the contributions of an early optical flare and forward shock emission. Methods. Our analysis reveals a gamma-ray precursor 17 s before the main pulse with a significantly softer spectrum (hardness ratio 0.37 +/- 0.12 versus 1.9 +/- 0.4). The optical afterglow shows an early peak at 76.0(-5.1)(+4.4) s characterized by a steep rise (alpha(flare,1) =4.1(-2.3)(+1.6)) and decay (alpha(flare,2) = 4.0(-1.5)(+2.1)), followed by forward shock emission with a broad hydrodynamic peak at around 150 s. In the subsequent plateau phase, the afterglow initially has a complex structure before settling into a final power law decay consistent with an electron distribution index p = 2.36(-0.15)(+0.18). The negligible host extinction (A(V,host) =0.073(-0.078)(+0.100)) suggests we are observing the intrinsic afterglow spectrum. The host system consists of two luminous (M-B similar to-21.7) components separated by 11.5 kpc at z = 1.069, which are possibly an interacting galaxy pair. Results. GRB 210312B provides a rare opportunity to study the prompt-to-afterglow transition in detail. The consistency of the forward shock component with standard afterglow theory supports our physical interpretation despite the lack of X-ray coverage.

Název v anglickém jazyce

From precursor to afterglow: The complex evolution of GRB 210312B

Popis výsledku anglicky

Context. Long gamma-ray bursts (GRBs) are characterized by a brief gamma-ray flash followed by a longer-lasting multiwavelength afterglow. The basic mechanism is largely understood, and the early afterglow evolution often shows complex features that provide crucial insights into the transition between prompt and afterglow phases. Aims. We present a detailed analysis of GRB 210312B, detected by INTEGRAL, which exhibits both a precursor and a complex optical afterglow evolution. Through careful modeling using Markov chain Monte Carlo methods, we disentangled the contributions of an early optical flare and forward shock emission. Methods. Our analysis reveals a gamma-ray precursor 17 s before the main pulse with a significantly softer spectrum (hardness ratio 0.37 +/- 0.12 versus 1.9 +/- 0.4). The optical afterglow shows an early peak at 76.0(-5.1)(+4.4) s characterized by a steep rise (alpha(flare,1) =4.1(-2.3)(+1.6)) and decay (alpha(flare,2) = 4.0(-1.5)(+2.1)), followed by forward shock emission with a broad hydrodynamic peak at around 150 s. In the subsequent plateau phase, the afterglow initially has a complex structure before settling into a final power law decay consistent with an electron distribution index p = 2.36(-0.15)(+0.18). The negligible host extinction (A(V,host) =0.073(-0.078)(+0.100)) suggests we are observing the intrinsic afterglow spectrum. The host system consists of two luminous (M-B similar to-21.7) components separated by 11.5 kpc at z = 1.069, which are possibly an interacting galaxy pair. Results. GRB 210312B provides a rare opportunity to study the prompt-to-afterglow transition in detail. The consistency of the forward shock component with standard afterglow theory supports our physical interpretation despite the lack of X-ray coverage.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Svazek periodika

698

Číslo periodika v rámci svazku

June

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

12

Strana od-do

A162

Kód UT WoS článku

001508300200015

EID výsledku v databázi Scopus

2-s2.0-105008882820