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View article: Photospheric emission from GRB 211211A altered by a strong radiation-mediated shock
Photospheric emission from GRB 211211A altered by a strong radiation-mediated shock Open
Gamma-ray burst (GRB) spectra are typically non-thermal, with many including two spectral breaks suggestive of optically thin emission. However, the emitted spectrum from a GRB photosphere, which includes prior dissipation of energy by rad…
View article: A Generalized Method to Measure the Lorentz Factor from Gamma-Ray Burst Photospheric Emission
A Generalized Method to Measure the Lorentz Factor from Gamma-Ray Burst Photospheric Emission Open
The properties of gamma-ray bursts (GRBs) that are inferred from observations depend on the value of the bulk Lorentz factor, Γ. Consequently, accurately estimating it is an important aim. In this work, we present a method of measuring Γ b…
View article: Empirical relations in thermal Comptonization
Empirical relations in thermal Comptonization Open
In many astrophysical systems, photons interact with matter through thermal Comptonization. In these cases, under certain simplifying assumptions, the evolution of the photon spectrum is described by an energy diffusion equation such as th…
View article: Intrapulse Spectral Evolution in Photospheric Gamma-Ray Bursts
Intrapulse Spectral Evolution in Photospheric Gamma-Ray Bursts Open
Photons that decouple from a relativistic jet do so over a range of radii, leading to a spreading in arrival times at the observer. Therefore, changes to the comoving photon distribution across the decoupling zone are encoded in the emitte…
View article: Radiation-mediated shocks in GRB prompt emission
Radiation-mediated shocks in GRB prompt emission Open
The debate regarding the emission mechanism in gamma-ray bursts has been long-standing. Here, we study the spectral signatures of photospheric emission, accounting for subphotospheric dissipation by a radiation-mediated shock. The shocks a…
View article: Ending the prompt phase in photospheric models of gamma-ray bursts
Ending the prompt phase in photospheric models of gamma-ray bursts Open
The early steep decay, a rapid decrease in X-ray flux as a function of time following the prompt emission, is a robust feature seen in almost all gamma-ray bursts with early enough X-ray observations. This peculiar phenomenon has often bee…
View article: Ending the prompt phase in photospheric models of gamma-ray bursts
Ending the prompt phase in photospheric models of gamma-ray bursts Open
The early steep decay, a rapid decrease in X-ray flux as a function of time following the prompt emission, is a robust feature seen in almost all gamma-ray bursts with early enough X-ray observations. This peculiar phenomenon has often bee…
View article: An efficient method for fitting radiation-mediated shocks to gamma-ray burst data: The Kompaneets RMS approximation
An efficient method for fitting radiation-mediated shocks to gamma-ray burst data: The Kompaneets RMS approximation Open
Shocks that occur below a gamma-ray burst (GRB) jet photosphere are mediated by radiation. Such radiation-mediated shocks (RMSs) could be responsible for shaping the prompt GRB emission. Although well studied theoretically, RMS models have…
View article: The problematic connection between low-luminosity gamma-ray bursts and ultra-high-energy cosmic rays
The problematic connection between low-luminosity gamma-ray bursts and ultra-high-energy cosmic rays Open
The origin of ultra-high-energy cosmic rays (UHECRs) remains debated. The prompt and afterglow phases of low-luminosity gamma-ray bursts (LLGRBs) are seen as promising candidates for this acceleration. Here, we investigate this connection …
View article: The problematic connection between gamma-ray bursts (GRBs) and ultra-high energy cosmic rays (UHECR)
The problematic connection between gamma-ray bursts (GRBs) and ultra-high energy cosmic rays (UHECR) Open
The acceleration site for UHECR is still an open question despite extended research and GRBs are considered one of the most promising source candidates. Under the likely assumption that electrons are also accelerated at the UHECR accelerat…