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Related papers: Time-Variable Diffuse $\gamma$-ray Foreground

200 papers

Photonic time-varying systems have attracted significant attention owing to their rich physics and potential opportunities for new and enhanced functionalities. In this context, the duality of space and time in wave physics has been…

Optics · Physics 2022-09-13 Zeki Hayran , Jacob B. Khurgin , Francesco Monticone

Cloud cover at the planetary limb of water-rich Earth-like planets is likely to weaken chemical signatures in transmission spectra, impeding attempts to characterize these atmospheres. However, based on observations of Earth and solar…

Earth and Planetary Astrophysics · Physics 2023-07-14 Maureen Cohen , Massimo A. Bollasina , Denis E. Sergeev , Paul I. Palmer , Nathan J. Mayne

The common approach to compute the cosmic-ray distribution in an starburst galaxy or region is equivalent to assume that at any point within that environment, there is an accelerator inputing cosmic rays at a reduced rate. This rate should…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Diego F. Torres , Analia Cillis , Brian Lacki , Yoel Rephaeli

We are investigating the possible origin of small-scale anomalies, like the annual stratospheric temperature anomalies. Unexpectedly within known physics, their observed planetary "dependency", does not match concurrent solar activity,…

Gamma-ray emission produced by interactions between cosmic rays (CRs) and interstellar gas traces the product of their densities throughout the Milky Way. The outer Galaxy is a privileged target of investigation to separate interstellar…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Luigi Tibaldo , Isabelle A. Grenier , Tsunefumi Mizuno

The propagation of $\gamma$ rays over very large distances provides new insights on the intergalactic medium and on fundamental physics. On their path to the Earth, $\gamma$ rays can annihilate with diffuse infrared or optical photons of…

High Energy Astrophysical Phenomena · Physics 2016-07-20 Dieter Horns , Agnieszka Jacholkowska

Reflections from objects in Earth orbit can produce sub-second, star-like optical flashes similar to astrophysical transients. Reflections have historically caused false alarms for transient surveys, but the population has not been…

Simulations of Galactic CR transport were performed with the software GALPROP, with the resulting gamma-ray flux calculated up to the PeV regime. The impact of altering parameters such as the number and distribution of CR sources, the…

High Energy Astrophysical Phenomena · Physics 2025-04-29 Peter Marinos

We consider nebulae which are created around binary systems containing rotation powered pulsars and companion stars with strong stellar winds. It is proposed that the stellar and pulsar winds have to mix at some distance from the binary…

High Energy Astrophysical Phenomena · Physics 2016-02-12 W. Bednarek , J. Sitarek

Dynamically, cosmic rays with energies above about one GeV/nucleon may be important agents of galaxy evolution. Their pressures compare with the thermal and magnetic ones impacting galactic gas accretion, fountains and galactic outflows,…

High Energy Astrophysical Phenomena · Physics 2022-05-18 A. Nuñez-Castiñeyra , I. A. Grenier , F. Bournaud , Y. Dubois , F. R. Kamal Youssef , P. Hennebelle

We present 3D models of the Galactic magnetic field including regular and turbulent components, and of the distribution of matter in the Galaxy including relativistic electrons and dust grains. By integrating along the line of sight, we…

Astrophysics of Galaxies · Physics 2013-03-26 L. Fauvet , J. F. Macías-Pérez , F. X. Désert

Recent optical afterglow observations of gamma-ray bursts indicate a setting and distance scale that many relate to star-formation regions. In this paper, we use $<V/V_{max}>$ and a set of artificial trigger thresholds to probe several…

Astrophysics · Physics 2009-10-31 H. Che , Y. Yang , R. J. Nemiroff

Optical observations of a sample of 12 $\gamma$-ray bright blazars from four optical data archives, AAVSO, SMARTS, Catalina, and Steward Observatory, are compiled to create densely sampled light curves spanning more than a decade. As a part…

High Energy Astrophysical Phenomena · Physics 2021-12-15 Gopal Bhatta

The Galactic gamma-ray diffuse emission (GDE) is emitted by cosmic rays (CRs), ultra-relativistic protons and electrons, interacting with gas and electromagnetic radiation fields in the interstellar medium. Here we present the analysis of…

<<>> Among the components of the infrared and submillimetre sky background, the closest layer is the thermal emission of dust particles and minor bodies in the Solar System. This contribution is especially important for current and future…

Astrophysics · Physics 2009-11-13 Cs. Kiss , A. Pal , Th. G. Mueller , P. Abraham

In almost any scenario for 'cosmological' gamma-ray bursts (and in many models where they originate in our own Galaxy), the initial energy density is so large that the resulting relativistic plasma expands with $v\sim c$ producing a blast…

Astrophysics · Physics 2009-10-22 P. Meszaros , M. J. Rees

We construct empirical models of the diffuse gamma-ray background toward the Galactic Center. Including all known point sources and a template of emission associated with interactions of cosmic rays with molecular gas, we show that the…

High Energy Astrophysical Phenomena · Physics 2014-07-23 Kevork N. Abazajian , Nicolas Canac , Shunsaku Horiuchi , Manoj Kaplinghat

The detection of astrophysical neutrinos from transient sources can help to understand the origin of the neutrino diffuse flux and to constrain the underlying production mechanisms. In particular, proton-neutron collisions may produce GeV…

Instrumentation and Methods for Astrophysics · Physics 2023-08-23 Mathieu Lamoureux , Gwenhaël de Wasseige

The solar disk is a bright gamma-ray source. Surprisingly, its flux is about one order of magnitude higher than predicted. As a first step toward understanding the physical origin of this discrepancy, we perform a new analysis in 1-100 GeV…

High Energy Astrophysical Phenomena · Physics 2016-07-13 Kenny C. Y. Ng , John F. Beacom , Annika H. G. Peter , Carsten Rott

Monitoring the evolution of the anthropogenic light emissions is a priority task in light pollution research. Among the complementary approaches that can be adopted to achieve this goal stand out those based on measuring the direct radiance…

Instrumentation and Methods for Astrophysics · Physics 2024-10-31 Salvador Bará