Article
Astronomy & Astrophysics
Alberto Sciaccaluga, Fabrizio Tavecchio
Summary: This article discusses the characteristics and radiation mechanisms of extreme TeV BL Lac blazars, proposing a new scenario in which non-thermal particles interact with turbulence in the jet. By solving a system of nonlinear coupled Fokker-Planck equations, the interaction is simulated and compared with observational data.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Shunke Ai, Bing Zhang
Summary: The study investigated blastwaves driven by magnetized ejecta and extended the mechanical model, showing better energy conservation performance. Testing the model, it was found that the deviation from energy conservation is negligibly small at small radii.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Eliot H. Ayache, Hendrik J. van Eerten, Rupert W. Eardley
Summary: Advancements in relativistic jet simulation techniques have enabled accurate numerical resolution of gamma-ray burst evolution. However, the modeling of emission lags behind, limiting full interpretation of GRB physics. A new code, GAMMA, combining moving-mesh relativistic dynamics with local treatment of non-thermal emission, has been developed to address this issue and allows for easy implementation of new solvers and geometries. Results show a shift in spectral cooling break and a change in temporal behavior, demonstrating the effectiveness of the approach.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Eliot H. Ayache, Hendrik J. van Eerten, Rupert W. Eardley
Summary: This paper introduces a new code gamma that combines recent developments in moving-mesh relativistic dynamics and local non-thermal emission treatment for simulating gamma-ray bursts. The research demonstrates the effectiveness of the approach by accurately calculating broad-band GRB afterglow radiation, showing promising results in the field.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Almog Yalinewich, Ue-Li Pen
Summary: Recent observations suggest that coherent radiation from the Crab pulsar is driven by an ultra-relativistic and cold plasma flow. A similar mechanism is proposed to explain the coherent emission in fast radio bursts (FRBs), where high Lorenz factors allow regular pulsars to explain FRBs instead of magnetars. This model can explain the observed frequency and time evolution of FRBs, as well as their duration, energetics, and absence of panchromatic counterparts. A variation of this model can also explain weaker radio transients observed from galactic magnetars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Gregory Vereshchagin, Liang Li, Damien Begue
Summary: This article discusses the unresolved question of the composition of relativistic outflows producing gamma-ray bursts, arguing that the absence of a photospheric component in their broad-band time-resolved spectra supports magnetically dominated outflows. However, the authors suggest that magnetic dominance is not necessary for interpreting this particular GRB, and simultaneous detection of high-energy emission in its prompt phase requires a departure from a one-zone emission model.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Hua-Yang Li, Hao-Ning He, Da-Ming Wei, Zhi-Ping Jin
Summary: This study focuses on the multiwavelength afterglow radiation of GRB 200415A and finds that the contribution of the forward and reverse shocks varies in different wavelength bands. Additionally, future telescopes are predicted to detect the optical and infrared afterglow emission from giant flares similar to GRB 200415A.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Tanima Mondal, Suman Pramanick, Lekshmi Resmi, Debanjan Bose
Summary: Detection of delayed sub-TeV photons from gamma-ray bursts (GRBs) by MAGIC and HESS has shown the potential of using the Cherenkov Telescope Array (CTA) for afterglow studies. This paper explores the detectability of sub-TeV photons by CTA using a one-zone electron synchrotron and synchrotron self-Compton model. The results suggest that jets with high kinetic energy or large bulk Lorentz factor decelerating into a dense ambient medium offer better detection prospects for CTA.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jirong Mao, Jiancheng Wang
Summary: The jitter radiation mechanism is proposed as a possible explanation for producing very high energy (VHE) photons emitted by high-energy objects, such as gamma-ray bursts. It has the potential to be applied to various types of VHE sources and offers a new perspective on understanding VHE emissions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Anabella T. Araudo, Marco Padovani, Alexandre Marcowith
Summary: The study reveals that protons in protostellar jets can reach high maximum energies and emit gamma rays in their interaction with matter fields. By combining synchrotron data with the theory of Bell instability, the magnetic field in the synchrotron emitter and the maximum energy of protons can be estimated.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Xiao-Li Huang, Ze-Rui Wang, Ruo-Yu Liu, Xiang-Yu Wang, En-Wei Liang
Summary: The study shows that the SSC emission from GRB afterglows in homogeneous and wind environments exhibit different characteristics and trends. Additionally, higher SSC flux is observed in high-density environments, but at the same time, more severe internal gamma-gamma absorption is also present.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Edwan Preau, Kunihito Ioka, Peter Meszaros
Summary: The theoretical model proposed in the study describes the structuring of a relativistic jet propagating through the ejecta of a binary neutron star merger event, taking into account the effects of neutron conversion-diffusion. This results in an increased baryon load structure of the outer jet with an energy distribution proportional to the off-axis angle.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
I Contopoulos, A. Strantzalis, D. Papadopoulos, D. Kazanas
Summary: The study focuses on long Gamma-Ray Bursts and proposes an electrodynamic model to explain their distinct characteristics, linking the sharp rise to the magnetic field winding by a fast-rotating core and the exponential decay to the electromagnetic spin-down of the core. Non-axisymmetric distortion generates gravitational waves with exponentially decreasing frequency, and specific time intervals are provided for testing the predicted waveforms in LIGO archival data.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Qiang Chen, Xue-Wen Liu
Summary: By extending the energy-conserving hydrodynamical model to the MHD limit, shocks originating from magnetized ejecta show a larger Lorentz factor in the whole shocked region, and higher total pressure in the forward shocked region compared to the reversed shocked region. Non-conservative models lose a significant percentage of their total energy in both ISM and wind cases, specifically in the forward shocked region, affecting the luminosity of shock synchrotron emission. However, once the energy conservation problem is solved, late-time light curves from the forward shock become independent of the ejecta magnetization, while early light curves from the reverse shock serve as important probes of the magnetization degree.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Vlasta Valan, Josefin Larsson
Summary: A study found that a small fraction of gamma-ray bursts (GRBs) exhibit blackbody emission in the X-ray spectra and the properties of the blackbody emission vary significantly, possibly associated with different parts of the jet.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
