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Related papers: Probing the dipole of the diffuse gamma-ray backgr…

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Recent data from the Pierre Auger Observatory has revealed the presence of a large-scale dipole in the arrival direction distribution of ultra-high energy cosmic rays (UHECR). In this work, we build up an understanding of the diffusive…

High Energy Astrophysical Phenomena · Physics 2021-03-09 Rodrigo Guedes Lang , Andrew M. Taylor , Vitor de Souza

Diffuse gamma-ray emission (DGE) has been discovered over the Galactic disk in the energy range from sub-GeV to sub-PeV. While it is believed to be dominated by the pionic emission of cosmic ray (CR) hadrons via interactions with…

High Energy Astrophysical Phenomena · Physics 2023-05-18 Kai Yan , Ruo-Yu Liu

The diffuse Galactic synchrotron emission (DGSE) is the most important diffuse foreground component for future cosmological 21-cm observations. The DGSE is also an important probe of the cosmic ray electron and magnetic field distributions…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-26 Sk. Saiyad Ali , Somnath Bharadwaj , Samir Choudhuri , Abhik Ghosh , Nirupam Roy

Very high energy (VHE, energy $E \gtrsim 100$\,GeV) \gamma-rays from cosmological sources are attenuated due to the interaction with photons of the extragalactic background light (EBL) in the ultraviolet to infrared wavelength band. The…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-05 Manuel Meyer , Martin Raue , Daniel Mazin , Dieter Horns

We search for dipole variations in the Hubble constant $H_0$ using gamma-ray burst (GRB) data, as such anisotropies may shed light on the Hubble tension. We employ the most recent and reliable GRB catalogs from the $E_{p}-E_{iso}$ and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-19 Orlando Luongo , Marco Muccino , Francesco Sorrenti

The discovery of distant sources of very high energy (VHE) gamma-rays with hard energy spectra enabled to derive strong upper limits on the density of the extragalactic background light (EBL). These limits are close to the lower limits…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-05 M. Raue

Ultra-high cosmic rays (UHECRs) with energies >10^19 eV emitted at cosmological distances will be attenuated by cosmic microwave and infrared background radiation through photohadronic processes. Lower energy extra-galactic cosmic rays…

High Energy Astrophysical Phenomena · Physics 2011-07-25 Xiang-Yu Wang , Ruo-Yu Liu , Felix Aharonian

We use dipole and quadrupole statistics to test the large-scale isotropy of the first 1005 gamma-ray bursts observed by the Burst and Transient Source Experiment (BATSE). In addition to the entire sample of 1005 gamma-ray bursts, many…

Star-forming galaxies are predicted to contribute considerably to the cosmic gamma-ray background (CGB) as they are confirmed gamma-ray emitters and are the most numerous population of gamma-ray sources, although individually faint. Even…

High Energy Astrophysical Phenomena · Physics 2009-12-18 Shin'ichiro Ando , Vasiliki Pavlidou

The direction and magnitude of the dipole anisotropy of ultra-high-energy cosmic rays with energies above 8 EeV observed by the Pierre Auger Observatory indicate their extragalactic origin. The observed dipole on Earth does not necessarily…

High Energy Astrophysical Phenomena · Physics 2024-02-13 Alena Bakalová , Jakub Vícha , Petr Trávníček

One of the main pillars of the {\Lambda}CDM model is the Cosmological Principle, which states that our Universe is statistically isotropic and homogeneous on large scales. Here we test this hypothesis using the Astrophysical Gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-06 Lorenzo Valbusa Dall'Armi , Angelo Ricciardone , Daniele Bertacca

Blazars represent the most abundant class of high-energy extragalactic $\gamma$-ray sources. The subset of blazars known as BL Lac objects is on average closer to Earth and characterized by harder spectra at high energy than the whole…

High Energy Astrophysical Phenomena · Physics 2016-05-26 M. Di Mauro , F. Donato , G. Lamanna , D. A. Sanchez , P. D. Serpico

The Extragalactic Background Light (EBL) can be probed via the absorption imprint it leaves in the spectra of gamma-ray sources ($\gamma\gamma \rightarrow e^-e^+$). We recently developed a dedicated technique to reconstruct the EBL, and its…

High Energy Astrophysical Phenomena · Physics 2019-04-03 Abhishek Desai , Kári Helgason , Marco Ajello , Vaidehi Paliya , Alberto Domínguez , Justin Finke , Dieter H. Hartmann

We present high sensitivity, low radio frequency continuum observations of the ELAIS-N1 field with 32 hours of observations of the uGMRT Band-2 ($120-250$ MHz) covering $5.86\,\text{deg}^2$ area, achieving a central off-source RMS noise of…

Diffuse gamma-ray emission has long been established as the most prominent feature in the GeV sky. Although the imaging atmospheric Cherenkov technique has been successful in revealing a large population of discrete TeV gamma-ray sources, a…

High Energy Astrophysical Phenomena · Physics 2019-08-15 K. Egberts , F. Brun , S. Casanova , W. Hofmann , M. de Naurois , O. Reimer , Q. Weitzel , Y. Fukui

We present deep optical and X-ray follow-up observations of the bright unassociated Fermi-LAT gammaray source 1FGL J1311.7-3429. The source was already known as an unidentified EGRET source (3EG J1314-3431, EGR J1314-3417), hence its nature…

High Energy Astrophysical Phenomena · Physics 2015-06-11 J. Kataoka , Y. Yatsu , N. Kawai , Y. Urata , C. C. Cheung , Y. Takahashi , K. Maeda , T. Totani , R. Makiya , H. Hanayama , T. Miyaji , A. Tsai

Star-forming galaxies (SFGs) are considered to be an important component of the diffuse extragalactic gamma-ray background (EGB) radiation observed in 0.1 -- 820 GeV, but their quantitative contribution has not yet been precisely…

High Energy Astrophysical Phenomena · Physics 2025-06-24 Junling Chen , Tomonori Totani

Foreground subtraction in global redshifted 21 cm measurements is limited by frequency-dependent (chromatic) structure in antenna beam patterns. Chromatic beams couple angular structures in Galactic foreground emission to spectral…

Instrumentation and Methods for Astrophysics · Physics 2015-12-09 Thomas J. Mozdzen , Judd D. Bowman , Raul A. Monsalve , Alan E. E. Rogers

A detailed knowledge of the Galactic radio continuum is of high interest for studies of the dynamics and structure of the Galaxy as well as for the problem of foreground removal in Cosmic Microwave Background measurements. In this work we…

Astrophysics · Physics 2011-05-23 P. Platania , C. Burigana , D. Maino , E. Caserini , M. Bersanelli , B. Cappellini , A. Mennella

Galactic diffuse continuum gamma-ray emission is intricately related to cosmic-ray physics and radio astronomy. We describe recent results from an approach which endeavours to take advantage of this. Information from cosmic-ray composition…

Astrophysics · Physics 2010-12-13 A. W. Strong , I. V. Moskalenko , O. Reimer
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