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We examine the possible role of turbulence in feeding the emission of gamma-ray bursts (GRBs). Turbulence may develop in a GRB jet as the result of hydrodynamic or current-driven instabilities. The jet carries dense radiation and the…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Jonathan Zrake , Andrei M. Beloborodov , Christoffer Lundman

This paper outlines an approach towards improved rigour in tokamak turbulence transport model validation within integrated modelling. Gaussian process regression (GPR) techniques were applied for profile fitting during the preparation of…

Calibrating for direction-dependent ionospheric distortions in visibility data is one of the main technical challenges that must be overcome to advance low-frequency radio astronomy. In this paper, we propose a novel probabilistic,…

Instrumentation and Methods for Astrophysics · Physics 2020-01-15 J. G. Albert , M. S. S. L. Oei , R. J. van Weeren , H. T. Intema , H. J. A. Röttgering

This paper discusses the effects of gravitational waves on high-accuracy astrometric observations such as those delivered by Gaia. Depending on the frequency of gravitational waves, two regimes for the influence of gravitational waves on…

High Energy Astrophysical Phenomena · Physics 2018-02-14 Sergei A. Klioner

A newly developed sensitivity-driven approach is employed to study the role of energetic particles in suppressing turbulence-inducing micro-instabilities for a set of realistic JET-like cases with NBI deuterium and ICRH $^3$He fast ions.…

Plasma Physics · Physics 2021-05-26 Ionut-Gabriel Farcas , Alessandro Di Siena , Frank Jenko

The sky distribution of Gamma-Ray Bursts (GRBs) has been intensively studied by various groups for more than two decades. Most of these studies test the isotropy of GRBs based on their sky number density distribution. In this work we…

High Energy Astrophysical Phenomena · Physics 2017-12-25 Jakub Ripa , Arman Shafieloo

Gamma-Ray Bursts (GRBs), being observed at high redshift (z = 9.4), vital to cosmological studies and investigating Population III stars. To tackle these studies, we need correlations among relevant GRB variables with the requirement of…

High Energy Astrophysical Phenomena · Physics 2023-08-16 Maria G. Dainotti , Ritwik Sharma , Aditya Narendra , Delina Levine , Enrico Rinaldi , Agnieszka Pollo , Gopal Bhatta

We investigate the ellipticity of the point-spread function (PSF) produced by imaging an unresolved source with a telescope, subject to the effects of atmospheric turbulence. It is important to quantify these effects in order to understand…

Astrophysics · Physics 2011-02-11 W. H. de Vries , S. S. Olivier , S. J. Asztalos , L. J. Rosenberg , K. L. Baker

New photometric space missions to detect and characterise transiting exoplanets are focusing on bright stars to obtain high cadence, high signal-to-noise light curves. Since these missions will be sensitive to stellar oscillations and…

Earth and Planetary Astrophysics · Physics 2020-02-12 S. C. C. Barros , O. Demangeon , R. F. Díaz , J. Cabrera , N. C. Santos , J. P. Faria , F. Pereira

We apply Gaussian processes (GP) in order to impose constraints on teleparallel gravity and its $f(T)$ extensions. We use available $H(z)$ observations from (i) cosmic chronometers data (CC); (ii) Supernova Type Ia (SN) data from the…

General Relativity and Quantum Cosmology · Physics 2021-02-03 Rebecca Briffa , Salvatore Capozziello , Jackson Levi Said , Jurgen Mifsud , Emmanuel N. Saridakis

The Gaia Data Release 1 (GDR1) is a first, important step on the path of evolution of astrometric accuracy towards a much improved situation. Although asteroids are not present in GDR1, this intermediate release already impacts asteroid…

Earth and Planetary Astrophysics · Physics 2017-11-08 F. Spoto , P. Tanga , S. Bouquillon , J. Desmars , D. Hestroffer , F. Mignard , M. Altmann , D. Herald , J. Marchant , C. Barache , T. Carlucci , T. Lister , F. Taris

A new method of measuring cosmology with gamma-ray bursts(GRBs) has been proposed by Liang and Zhang recently. In this method, only observable quantities including the rest frame peak energy of the \nu F_\nu spectrum (E'_p), the isotropic…

Astrophysics · Physics 2009-11-13 F. Y. Wang , Z. G. Dai

The ultimate performance of coronagraphic high contrast exoplanet imaging systems such as SPHERE or GPI is limited by quasi-static aberrations. These aberrations produce speckles that can be mistaken for planets in the image. In order to…

Instrumentation and Methods for Astrophysics · Physics 2017-01-31 Olivier Herscovici-Schiller , Laurent M. Mugnier , Jean-François Sauvage

Using very long baseline interferometry (VLBI) observations at (sub)millimeter wavelengths, the Event Horizon Telescope (EHT) currently achieves the finest angular resolution of any astronomical facility, necessary for imaging the…

Instrumentation and Methods for Astrophysics · Physics 2025-10-23 Uri Rolls , Dominic W. Pesce , Paul Tiede , Lindy Blackburn , Iniyan Natarajan , Sheperd S. Doeleman

The canonical methods for gravitational wave detection are ground- and space-based laser interferometry, pulsar timing, and polarization of the cosmic microwave background. But as has been suggested by numerous investigators, astrometry…

Instrumentation and Methods for Astrophysics · Physics 2018-07-25 Jeremy Darling , Alexandra E. Truebenbach , Jennie Paine

The fluctuations produced during cosmic inflation may exhibit non-Gaussian characteristics that are imprinted in the large-scale structure of the Universe. This non-Gaussian imprint is an ultra-large scale signal that can be detected using…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-11 Mponeng Kopana , Sheean Jolicoeur , Roy Maartens

The inference of stellar parameters (such as radius and mass) through asteroseismic forward modelling depends on the number, accuracy, and precision of seismic and atmospheric constraints. ESA's Gaia space mission is providing precise…

Solar and Stellar Astrophysics · Physics 2024-12-09 Benard Nsamba , Achim Weiss , Juma Kamulali

The amount of sparse asteroid photometry being gathered by both space- and ground-based surveys is growing exponentially. This large volume of data poses a computational challenge owing to both the large amount of information to be…

An important application of next-generation wide-field radio interferometers is making high dynamic range maps of radio emission. Traditional deconvolution methods like CLEAN can give poor recovery of diffuse structure, prompting the…

Instrumentation and Methods for Astrophysics · Physics 2024-10-23 Katrine A. Glasscock , Philip Bull , Jacob Burba , Hugh Garsden , Michael J. Wilensky