Clues from the prompt emission of GRB 080319B

Abstract

The extremely bright optical flash that accompanied GRB 080319B suggested, at first glance, that the prompt $\gamma$-rays in this burst were produced by Synchrotron self Compton (SSC). We analyze here the observed optical and $\gamma$ spectrum. We find that the very strong optical emission poses, due to self absorption, very strong constraints on the emission processes and put the origin of the optical emission at a very large radius, almost inconsistent with internal shock. Alternatively it requires a very large random Lorentz factor for the electrons. We find that SSC could not have produced the prompt $\gamma$-rays. We also show that the optical emission and the $\gamma$ rays could not have been produced by synchrotron emission from two populations of electron within the same emitting region. Thus we must conclude that the optical and the $\gamma$-rays were produced in different physical regions. A possible interpretation of the observations is that the $\gamma$-rays arose from internal shocks but the optical flash resulted from external shock emission. This would have been consistent with the few seconds delay observed between the optical and $\gamma$-rays signals.

References in corpus (16)

• The Physics of Gamma-Ray Bursts
• Observation of contemporaneous optical radiation from a gamma-ray burst
• Predictions for The Very Early Afterglow and The Optical Flash
• GRB990123, The Optical Flash and The Fireball Model
• GRB 990123: Reverse and Internal Shock Flashes and Late Afterglow
• Low Frequency Spectra of Gamma-Ray Bursts
• Early Afterglow Emission from a Reverse Shock as a Diagnostic Tool for GRB Outflows
• A contemporaneous infrared flash from a long gamma-ray burst: an echo from the central engine
• A general scheme for modeling gamma-ray burst prompt emission
• Detection of a very bright optical flare from a gamma-ray burst at redshift 6.29
• Ultra Efficient Internal Shocks
• High energy gamma-ray emission from Gamma-Ray Bursts -- before GLAST
• The optical flare and afterglow light curve of GRB 050904 at redshift z=6.29
• Continuous optical monitoring during the prompt emission of GRB 060111B
• Prompt optical emission from residual collisions in GRB outflows
• Is GRB 050904 a super-long burst?

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• Gamma-Ray Bursts in the Swift Era
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• Open Questions in GRB Physics
• Constraints on the Synchrotron Emission Mechanism in GRBs
• Expected high energy emission from GRB 080319B and origins of the GeV emission of GRBs 080514B, 080916C and 081024B
• Cosmic Transients Test Einstein's Equivalence Principle out to GeV Energies
• Fast optical variability of Naked-Eye Burst - manifestation of periodic activity of internal engine
• Late time observations of GRB080319B: jet break, host galaxy and accompanying supernova
• GRB 090727 and gamma-ray bursts with early time optical emission
• A detailed spectral study of GRB 041219A and its host galaxy
• Inverse Compton cooling in Klein-Nishina regime and GRB prompt spectrum
• The origin of the optical flashes: The case study of GRB 080319B and GRB 130427A
• Adiabatic expansion, early x-ray data and the central engine in GRBs
• Photospheric Prompt Emission From Long Gamma Ray Burst Simulations -- I. Optical Emission
• Gamma Ray Burst Prompt Emission Variability in Synchrotron and Synchrotron Self-Compton Lightcurves
• Gamma-Ray Burst prompt emission from the synchrotron radiation of relativistic electrons in a rapidly decaying magnetic field
• A Small, Rapid Optical-IR Response Gamma-Ray Burst Space Observatory (The NGRG)
• Quark-nova explosion inside a collapsar: application to Gamma Ray Bursts
• Prompt Optical Emission from Gamma-ray Bursts with Non-single Timescale Variability of Central Engine Activities