Related papers: Background for a gamma-ray satellite on a low-Eart…

Semi-Analytic Model for Intergalactic Gamma-Ray Cascades in Extragalactic Magnetic Fields

Primary gamma rays emitted by extragalactic sources, such as blazars, will generate electromagnetic cascades in intergalactic space. These cascades proceed via electron-positron pair production and inverse Compton scattering on cosmic…

High Energy Astrophysical Phenomena · Physics 2011-09-14 H. Huan , T. Weisgarber

Extragalactic Very-High-Energy gamma-ray background

We study the origin of the extragalactic diffuse gamma-ray background using the data from the Fermi telescope. To estimate the background level, we count photons at high Galactic latitudes |b|>60 degrees. Subtracting photons associated to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 A. Neronov , D. V. Semikoz

Trapped proton fluxes at low Earth orbits measured by the PAMELA experiment

We report an accurate measurement of the geomagnetically trapped proton fluxes for kinetic energy above > 70 MeV performed by the PAMELA mission at low Earth orbits (350-610 km). Data were analyzed in the frame of the adiabatic theory of…

Earth and Planetary Astrophysics · Physics 2015-01-29 O. Adriani , G. C. Barbarino , G. A. Bazilevskaya , R. Bellotti , M. Boezio , E. A. Bogomolov , M. Bongi , V. Bonvicini , S. Bottai , A. Bruno , F. Cafagna , D. Campana , R. Carbone , P. Carlson , M. Casolino , G. Castellini , I. A. Danilchenko , C. De Donato , C. De Santis , N. De Simone , V. Di Felice , V. Formato , A. M. Galper , A. V. Karelin , S. V. Koldashov , S. Koldobskiy , S. Y. Krutkov , A. N. Kvashnin , A. Leonov , V. Malakhov , L. Marcelli , M. Martucci , A. G. Mayorov , W. Menn , M. Mergé , V. V. Mikhailov , E. Mocchiutti , A. Monaco , N. Mori , R. Munini , G. Osteria , F. Palma , B. Panico , P. Papini , M. Pearce , P. Picozza , M. Ricci , S. B. Ricciarini , R. Sarkar , V. Scotti , M. Simon , R. Sparvoli , P. Spillantini , Y. I. Stozhkov , A. Vacchi , E. Vannuccini , G. I. Vasilyev , S. A. Voronov , Y. T. Yurkin , G. Zampa , N. Zampa , V. G. Zverev

High-(Energy)-Lights -- The Very High Energy Gamma-Ray Sky

The high-lights of ground-based very-high-energy (VHE, $E>100$ GeV) gamma-ray astronomy are reviewed. The summary covers both Galactic and extra-galactic sources. A total of at least 70 sources are currently known. Implications for our…

Astrophysics · Physics 2015-05-13 D. Horns

Cygnus X-3: A variable petaelectronvolt gamma-ray source

We report the discovery of variable $\gamma$-rays up to petaelectronvolt from Cygnus X-3, an iconic X-ray binary. The $\gamma$-ray signal was detected with a statistical significance of approximately 10 $\sigma$ by the Large High Altitude…

High Energy Astrophysical Phenomena · Physics 2026-04-14 The LHAASO Collaboration , Zhen Cao , F. Aharonian , Y. X. Bai , Y. W. Bao , D. Bastieri , X. J. Bi , Y. J. Bi , W. Bian , J. Blunier , A. V. Bukevich , C. M. Cai , Y. Y. Cai , W. Y. Cao , Zhe Cao , J. Chang , J. F. Chang , E. S. Chen , G. H. Chen , H. K. Chen , L. F. Chen , Liang Chen , Long Chen , M. J. Chen , M. L. Chen , Q. H. Chen , S. Chen , S. H. Chen , S. Z. Chen , T. L. Chen , X. B. Chen , X. J. Chen , X. P. Chen , Y. Chen , N. Cheng , Q. Y. Cheng , Y. D. Cheng , M. Y. Cui , S. W. Cui , X. H. Cui , Y. D. Cui , B. Z. Dai , H. L. Dai , Z. G. Dai , Danzengluobu , Y. X. Diao , A. J. Dong , X. Q. Dong , K. K. Duan , J. H. Fan , Y. Z. Fan , J. Fang , J. H. Fang , K. Fang , C. F. Feng , H. Feng , L. Feng , S. H. Feng , X. T. Feng , Y. Feng , Y. L. Feng , S. Gabici , B. Gao , Q. Gao , W. Gao , W. K. Gao , M. M. Ge , T. T. Ge , L. S. Geng , G. Giacinti , G. H. Gong , Q. B. Gou , M. H. Gu , F. L. Guo , J. Guo , K. J. Guo , X. L. Guo , Y. Q. Guo , Y. Y. Guo , R. P. Han , O. A. Hannuksela , M. Hasan , H. H. He , H. N. He , J. Y. He , X. Y. He , Y. He , S. Hernández-Cadena , B. W. Hou , C. Hou , X. Hou , H. B. Hu , S. C. Hu , C. Huang , D. H. Huang , J. J. Huang , X. L. Huang , X. T. Huang , X. Y. Huang , Y. Huang , Y. Y. Huang , A. Inventar , X. L. Ji , H. Y. Jia , K. Jia , H. B. Jiang , K. Jiang , X. W. Jiang , Z. J. Jiang , M. Jin , S. Kaci , M. M. Kang , I. Karpikov , D. Khangulyan , D. Kuleshov , K. Kurinov , Cheng Li , Cong Li , D. Li , F. Li , H. B. Li , H. C. Li , Jian Li , Jie Li , K. Li , L. Li , R. L. Li , S. D. Li , T. Y. Li , W. L. Li , X. R. Li , Xin Li , Y. Li , Zhe Li , Zhuo Li , E. W. Liang , Y. F. Liang , S. J. Lin , B. Liu , C. Liu , D. Liu , D. B. Liu , H. Liu , J. Liu , J. L. Liu , J. R. Liu , M. Y. Liu , R. Y. Liu , S. M. Liu , W. Liu , X. Liu , Y. Liu , Y. Liu , Y. N. Liu , Y. Q. Lou , Q. Luo , Y. Luo , H. K. Lv , B. Q. Ma , L. L. Ma , X. H. Ma , I. O. Maliy , J. R. Mao , Z. Min , W. Mitthumsiri , Y. Mizuno , G. B. Mou , A. Neronov , K. C. Y. Ng , M. Y. Ni , L. Nie , L. J. Ou , Z. W. Ou , P. Pattarakijwanich , Z. Y. Pei , D. Y. Peng , J. C. Qi , M. Y. Qi , J. J. Qin , D. Qu , A. Raza , C. Y. Ren , D. Ruffolo , A. Sáiz , D. Savchenko , D. Semikoz , L. Shao , O. Shchegolev , Y. Z. Shen , X. D. Sheng , Z. D. Shi , F. W. Shu , H. C. Song , Yu. V. Stenkin , V. Stepanov , Y. Su , D. X. Sun , H. Sun , J. X. Sun , Q. N. Sun , X. N. Sun , Z. B. Sun , N. H. Tabasam , J. Takata , P. H. T. Tam , H. B. Tan , Q. W. Tang , R. Tang , Z. B. Tang , W. W. Tian , C. N. Tong , L. H. Wan , C. Wang , D. H. Wang , G. W. Wang , H. G. Wang , J. C. Wang , K. Wang , Kai Wang , Kai Wang , L. P. Wang , L. Y. Wang , L. Y. Wang , R. Wang , W. Wang , X. G. Wang , X. J. Wang , X. Y. Wang , Y. Wang , Y. D. Wang , Z. H. Wang , Z. X. Wang , Zheng Wang , D. M. Wei , J. J. Wei , Y. J. Wei , T. Wen , S. S. Weng , C. Y. Wu , H. R. Wu , Q. W. Wu , S. Wu , X. F. Wu , Y. S. Wu , S. Q. Xi , J. Xia , J. J. Xia , G. M. Xiang , D. X. Xiao , G. Xiao , Y. F. Xiao , Y. L. Xin , H. D. Xing , Y. Xing , D. R. Xiong , B. N. Xu , C. Y. Xu , D. L. Xu , R. F. Xu , R. X. Xu , S. S. Xu , W. L. Xu , L. Xue , D. H. Yan , T. Yan , C. W. Yang , C. Y. Yang , F. F. Yang , L. L. Yang , M. J. Yang , R. Z. Yang , W. X. Yang , Z. H. Yang , Z. G. Yao , X. A. Ye , L. Q. Yin , N. Yin , X. H. You , Z. Y. You , Q. Yuan , H. Yue , H. D. Zeng , T. X. Zeng , W. Zeng , X. T. Zeng , M. Zha , B. B. Zhang , B. T. Zhang , C. Zhang , H. Zhang , H. M. Zhang , H. Y. Zhang , J. L. Zhang , J. Y. Zhang , Li Zhang , P. F. Zhang , R. Zhang , S. R. Zhang , S. S. Zhang , S. Y. Zhang , W. Zhang , W. Y. Zhang , X. Zhang , X. P. Zhang , Yi Zhang , Yong Zhang , Z. P. Zhang , J. Zhao , L. Zhao , L. Z. Zhao , S. P. Zhao , X. H. Zhao , Z. H. Zhao , F. Zheng , T. C. Zheng , B. Zhou , H. Zhou , J. N. Zhou , M. Zhou , P. Zhou , R. Zhou , X. X. Zhou , X. X. Zhou , B. Y. Zhu , C. G. Zhu , F. R. Zhu , H. Zhu , K. J. Zhu , Y. C. Zou , X. Zuo , J. S. Wang

The contribution of AGNs to the X-ray background

We report the results of a detailed analysis of the contribution of various classes of AGNs to the extragalactic X-ray background (XRB). The model is based on the unification schemes of AGNs and on their related X-ray spectral properties in…

Astrophysics · Physics 2011-05-23 A. Comastri , G. Setti , G. Zamorani , G. Hasinger

Cosmological Lower Bound on Dark Matter Masses from the Soft Gamma-ray Background

Motivated by a recent detection of 511 keV photons from the center of our Galaxy, we calculate the spectrum of the soft gamma-ray background of the redshifted 511 keV photons from cosmological halos. Annihilation of dark matter particles…

Astrophysics · Physics 2009-11-10 Kyungjin Ahn , Eiichiro Komatsu

Lower bounds of altitudes for pulsar $\gamma$-ray radiation

Determining radiation location observationally plays a very important role in testing the pulsar radiation models. One-photon pair production in the strong magnetic field, $\gamma-e^{+}e^{1}$, is one of the important physical processes in…

High Energy Astrophysical Phenomena · Physics 2010-09-20 K. J. Lee , Y. J. Du , H. G. Wang , G. J. Qiao , R. X. Xu , J. L. Han

Two active states of the narrow-line gamma-ray-loud AGN GB 1310+487

Previously unremarkable, the extragalactic radio source GB 1310+487 showed a gamma-ray flare on 2009 November 18, reaching a daily flux of ~10^-6 photons/cm^2/s at energies E>100 MeV and becoming one of the brightest GeV sources for about…

High Energy Astrophysical Phenomena · Physics 2014-05-08 K. V. Sokolovsky , F. K. Schinzel , Y. T. Tanaka , P. K. Abolmasov , E. Angelakis , A. Bulgarelli , L. Carrasco , S. B. Cenko , C. C. Cheung , K. I. Clubb , F. D'Ammando , L. Escande , S. J. Fegan , A. V. Filippenko , J. D. Finke , L. Fuhrmann , Y. Fukazawa , E. Hays , S. E. Healey , Y. Ikejiri , R. Itoh , K. S. Kawabata , T. Komatsu , Yu. A. Kovalev , Y. Y. Kovalev , T. P. Krichbaum , S. Larsson , M. L. Lister , B. Lott , W. Max-Moerbeck , I. Nestoras , C. Pittori , T. Pursimo , A. B. Pushkarev , A. C. S. Readhead , E. Recillas , J. L. Richards , D. Riquelme , R. W. Romani , K. Sakimoto , M. Sasada , R. Schmidt , M. S. Shaw , A. Sievers , D. J. Thompson , M. Uemura , H. Ungerechts , S. Vercellone , F. Verrecchia , M. Yamanaka , M. Yoshida , J. A. Zensus

Performance of an Algorithm for Estimation of Flux, Background and Location on One-Dimensional Signals

Optimal estimation of signal amplitude, background level, and photocentre location is crucial to the combined extraction of astrometric and photometric information from focal plane images, and in particular from the one-dimensional…

Instrumentation and Methods for Astrophysics · Physics 2017-04-05 Mario Gai , Deborah Busonero , Rossella Cancelliere

Beacons at the Gamma Ray Horizon

Blazars with redshifts z<0.1 are likely candidates for detection at energies in the range 300 GeV - 50 TeV with Cerenkov telescopes and scintillator arrays. We present gamma-ray flux predictions for a sample of 15 nearby flat-spectrum radio…

Astrophysics · Physics 2011-05-23 K. Mannheim , S. Westerhoff , H. Meyer , H. -H. Fink

On the contribution of unresolved blazars to the extragalactic gamma ray background

We present a model for estimating the blazar contribution to the extragalactic gamma-ray background (EGRB) in the EGRET energy range. It is based on inverse-Compton scattering as the dominant gamma-ray production process in the jets of flat…

Astrophysics · Physics 2007-05-23 A. Muecke , M. Pohl

$\gamma$-Cascade V4: A Semi-Analytical Code for Modeling Cosmological Gamma-Ray Propagation

Since the universe is not transparent to gamma rays with energies above around one hundred GeV, it is necessary to account for the interaction of high-energy photons with intergalactic radiation fields in order to model gamma-ray…

High Energy Astrophysical Phenomena · Physics 2025-05-16 Antonio Capanema , Carlos Blanco

Atmospheres and Spectra of Strongly Magnetized Neutron Stars

We construct atmosphere models for strongly magnetized neutron stars with surface fields $B\sim 10^{12}-10^{15}$ G and effective temperatures $T_{\rm eff}\sim 10^6-10^7$ K. The atmospheres directly determine the characteristics of thermal…

Astrophysics · Physics 2008-11-26 Wynn C. G. Ho , Dong Lai

Detecting a Stochastic Gravitational Wave Background in the presence of a Galactic Foreground and Instrument Noise

Detecting a stochastic gravitational wave background requires that we first understand and model any astrophysical foregrounds. In the millihertz frequency band, the predominate foreground signal will be from unresolved white dwarf binaries…

General Relativity and Quantum Cosmology · Physics 2014-01-23 Matthew R. Adams , Neil J. Cornish

Energetic Neutral Atom Imaging of Planetary Environments

The aim of this work is to investigate the applications of the neutral atom imaging to the environments of the Earth, Mars and Mercury. This innovative technique permits the study of energetic plasma by means of analysing the result of the…

Earth and Planetary Astrophysics · Physics 2023-02-23 Alessandro Mura

The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV

The {\gamma}-ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, and a residual all-sky emission component commonly called the…

High Energy Astrophysical Phenomena · Physics 2015-06-02 The Fermi LAT collaboration , M. Ackermann , M. Ajello , A. Albert , W. B. Atwood , L. Baldini , J. Ballet , G. Barbiellini , D. Bastieri , K. Bechtol , R. Bellazzini , E. Bissaldi , R. D. Blandford , E. D. Bloom , E. Bottacini , T. J. Brandt , J. Bregeon , P. Bruel , R. Buehler , S. Buson , G. A. Caliandro , R. A. Cameron , M. Caragiulo , P. A. Caraveo , E. Cavazzuti , C. Cecchi , E. Charles , A. Chekhtman , J. Chiang , G. Chiaro , S. Ciprini , R. Claus , J. Cohen-Tanugi , J. Conrad , A. Cuoco , S. Cutini , F. D'Ammando , A. de Angelis , F. de Palma , C. D. Dermer , S. W. Digel , E. do Couto e Silva , P. S. Drell , C. Favuzzi , E. C. Ferrara , W. B. Focke , A. Franckowiak , Y. Fukazawa , S. Funk , P. Fusco , F. Gargano , D. Gasparrini , S. Germani , N. Giglietto , P. Giommi , F. Giordano , M. Giroletti , G. Godfrey , G. A. Gomez-Vargas , I. A. Grenier , S. Guiriec , M. Gustafsson , D. Hadasch , K. Hayashi , E. Hays , J. W. Hewitt , P. Ippoliti , T. Jogler , G. Jóhannesson , A. S. Johnson , W. N. Johnson , T. Kamae , J. Kataoka , J. Knödlseder , M. Kuss , S. Larsson , L. Latronico , J. Li , L. Li , F. Longo , F. Loparco , B. Lott , M. N. Lovellette , P. Lubrano , G. M. Madejski , A. Manfreda , F. Massaro , M. Mayer , M. N. Mazziotta , J. E. McEnery , P. F. Michelson , W. Mitthumsiri , T. Mizuno , A. A. Moiseev , M. E. Monzani , A. Morselli , I. V. Moskalenko , S. Murgia , R. Nemmen , E. Nuss , T. Ohsugi , N. Omodei , E. Orlando , J. F. Ormes , D. Paneque , J. H. Panetta , J. S. Perkins , M. Pesce-Rollins , F. Piron , G. Pivato , T. A. Porter , S. Rainò , R. Rando , M. Razzano , S. Razzaque , A. Reimer , O. Reimer , T. Reposeur , S. Ritz , R. W. Romani , M. Sánchez-Conde , M. Schaal , A. Schulz , C. Sgrò , E. J. Siskind , G. Spandre , P. Spinelli , A. W. Strong , D. J. Suson , H. Takahashi , J. G. Thayer , J. B. Thayer , L. Tibaldo , M. Tinivella , D. F. Torres , G. Tosti , E. Troja , Y. Uchiyama , G. Vianello , M. Werner , B. L. Winer , K. S. Wood , M. Wood , G. Zaharijas , S. Zimmer

Ground based Gamma Ray Studies based on Atmospheric Cherenkov technique at high mountain altitude

In this paper we present a new method for ground based gamma ray astronomy based only on atmospheric Cherenkov light flux analysis. The Cherenkov light flux densities in extensive air showers (EAS) initiated by different primaries are…

Astrophysics · Physics 2009-11-10 A. Mishev , S. Mavrodiev , J. Stamenov

Inverse problem in Ionospheric Science: Prediction of solar soft-X-ray spectrum from Very Low Frequency Radiosonde results

X-rays and gamma-rays from astronomical sources such as solar flares are mostly absorbed by the Earth's atmosphere. Resulting electron-ion production rate as a function of height depends on the intensity and wavelength of the injected…

Earth and Planetary Astrophysics · Physics 2016-04-27 Sourav Palit , Suman Ray , Sandip K. Chakrabarti

Simulation of the AGILE gamma-ray imaging detector performance: part I

We present in this paper the results of a comprehensive GEANT simulation of the Gamma-Ray Imaging Detector (GRID) being developed for the AGILE space astrophysics mission. The GRID is designed to be sensitive in the 30 MeV - 50 GeV energy…

Astrophysics · Physics 2015-06-24 Francesco Longo , Veronica Cocco , Marco Tavani