From precursor to afterglow: The complex evolution of GRB 210312B
The result's identifiers
Result code in 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>
Alternative codes found
RIV/68378271:_____/25:00636816 RIV/68407700:21230/25:00383956
Result on the web
<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>
Alternative languages
Result language
angličtina
Original language name
From precursor to afterglow: The complex evolution of GRB 210312B
Original language description
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.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Astronomy & Astrophysics
ISSN
0004-6361
e-ISSN
1432-0746
Volume of the periodical
698
Issue of the periodical within the volume
June
Country of publishing house
FR - FRANCE
Number of pages
12
Pages from-to
A162
UT code for WoS article
001508300200015
EID of the result in the Scopus database
2-s2.0-105008882820