Properties of the Prompt Optical Counterpart Arising from the Cooling of Electrons in Gamma-Ray Bursts
Journal Article
·
· The Astrophysical Journal
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
This work extends a contemporaneous effort to study the properties of the lower-energy counterpart synchrotron emission produced by the cooling of relativistic gamma-ray burst (GRB) electrons through radiation (synchrotron and self-Compton) emission and adiabatic losses. We derive the major characteristics (pulse duration, lag time after burst, and brightness relative to the burst) of the prompt optical counterpart (POC) occurring during or after the GRB. Depending on the magnetic field lifetime, duration of electron injection, and electron transit time Δto from hard X-ray (GRB) to optical-emitting energies, a POC may appear during the GRB pulse (of duration δtγ) or after (delayed OC). The signature of counterparts arising from the cooling of GRB electrons is that POC pulses (Δto < δtγ) last as long as the corresponding GRB pulse (δto ≃ δtγ), while delayed OC pulses (Δto > δtγ) last as long as the transit time (δto ≃ Δto). If OC variability can be measured, then another signature for this OC mechanism is that the GRB variability is passed on to POCs but not to delayed OCs. Within the GRB electron cooling model for counterparts, POCs should be on average dimmer than delayed ones (consistent with the data), and harder GRB low-energy slopes βLE should be associated more often with the dimmer POCs. The latter sets an observational bias against detecting POCs from (the cooling of electrons in) GRBs with a hard slope βLE, making it more likely that the detected POCs of such bursts arise from another mechanism.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- 89233218CNA000001
- OSTI ID:
- 1897443
- Report Number(s):
- LA-UR-22-28294
- Journal Information:
- The Astrophysical Journal, Journal Name: The Astrophysical Journal Journal Issue: 2 Vol. 938; ISSN 0004-637X
- Publisher:
- IOP PublishingCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
The Synchrotron Low-energy Spectrum Arising from the Cooling of Electrons in Gamma-Ray Bursts
Fermi Observations of GRB 090510: A Short Hard Gamma-Ray Burst with an Additional, Hard Power-Law Component from 10 keV to GeV Energies
Gamma-ray burst spectrum with decaying magnetic field
Journal Article
·
Wed Oct 19 20:00:00 EDT 2022
· The Astrophysical Journal
·
OSTI ID:1897440
Fermi Observations of GRB 090510: A Short Hard Gamma-Ray Burst with an Additional, Hard Power-Law Component from 10 keV to GeV Energies
Journal Article
·
Wed May 26 20:00:00 EDT 2010
· The Astrophysical Journal
·
OSTI ID:1357548
Gamma-ray burst spectrum with decaying magnetic field
Journal Article
·
Tue Dec 31 23:00:00 EST 2013
· Astrophysical Journal
·
OSTI ID:22348369