CNN emulator for decaying magnetic field fast-cooling synchrotron spectra is trained on synthetic data and used in Bayesian fits to GRB 231020A, favoring the decaying-field model over the standard version.
Unsteady Outflow Models for Cosmological Gamma-Ray Bursts
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
The 'event' that triggers a gamma ray burst cannot last for more than a few seconds. This is, however, long compared with the dynamical timescale of a compact stellar-mass object ($\sim 10^{-3}$ seconds). Energy is assumed to be released as an outflow with high mean lorentz factor $\Gamma$. But a compact stellar-mass collapse or merger is, realistically, likely to generate a mass (or energy) flux that is unsteady on some timescales in the range $10^{-3}$ - 10 seconds. If $\Gamma$ fluctuates by a factor of $\sim 2$ around its mean value, relative motions within the outflowing material will themselves (in the comoving frame) be relativistic, and can give rise to internal shocks. For $\Gamma \sim 10^2$, the resultant dissipation occurs outside the 'photosphere' and can convert a substantial fraction of the overall outflow energy into non-thermal radiation. This suggests a mechanism for cosmological bursts that demands less extreme assumptions (in respect of $\Gamma$-values, freedom from baryonic contamination, etc) than earlier proposals.
fields
astro-ph.HE 3years
2026 3verdicts
UNVERDICTED 3representative citing papers
Time lags between energy bands serve as proxies for spectral evolution in GRBs, with positive lags tracing prompt emission softening and negative lags indicating a new delayed high-energy component.
GRB 250424A afterglow shows simultaneous shallow decay in X-ray and optical bands modeled as continuous energy injection (q≈0.34) into a forward shock in constant-density medium, with E_K,iso ≈5.5×10^52 erg and no clear supernova component.
citing papers explorer
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Modeling Gamma-Ray Burst Spectra with Convolutional Neural Networks: Fast-Cooling Synchrotron Emission in a Decaying Magnetic Field
CNN emulator for decaying magnetic field fast-cooling synchrotron spectra is trained on synthetic data and used in Bayesian fits to GRB 231020A, favoring the decaying-field model over the standard version.
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Time lags as proxy of spectral evolution in gamma-ray bursts
Time lags between energy bands serve as proxies for spectral evolution in GRBs, with positive lags tracing prompt emission softening and negative lags indicating a new delayed high-energy component.
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GRB 250424A: A Case Study of Energy Injection with Multiwavelength Observations
GRB 250424A afterglow shows simultaneous shallow decay in X-ray and optical bands modeled as continuous energy injection (q≈0.34) into a forward shock in constant-density medium, with E_K,iso ≈5.5×10^52 erg and no clear supernova component.