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Photometric observations of galaxies at submillimetre to millimetre wavelengths (50 - 1000 GHz) are susceptible to spatial variations in both the background CMB temperature and CIB emission that can be comparable to the flux from the target…

Astrophysics of Galaxies · Physics 2015-06-22 Simone Ferraro , Brandon Hensley

There is tentative evidence for a mismatch between the rest frames of matter and the cosmic microwave background, the "quasar dipole anomaly". We consider such a dipole in tilted anisotropic models, for a range of scenarios and sources:…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-04 Alicia Martín , Constantinos Skordis , Deaglan J. Bartlett , Harry Desmond , Pedro G. Ferreira , Tariq Yasin

We search for the long-term variability of the \gamma-ray sky in the energy range E > 1 GeV with 168 weeks of Fermi-LAT data. We perform a full sky blind search for regions with variable flux looking for deviations from uniformity. We bin…

High Energy Astrophysical Phenomena · Physics 2015-06-03 M. S. Pshirkov , G. I. Rubtsov

The light emitted by all galaxies over the history of the Universe produces the extragalactic background light (EBL) at ultraviolet, optical, and infrared wavelengths. The EBL is a source of opacity for $\gamma$ rays via photon-photon…

High Energy Astrophysical Phenomena · Physics 2018-12-05 LAT Collaboration , M. Ajello , K. Helgason , V. Paliya , J. Finke , A. Dominguez , A. Desai

The cosmic ray energy spectra of protons and helium nuclei, which are the most abundant components of cosmic radiation, exhibit a remarkable hardening at energies above one hundred GeV/nucleon. Recent data from AMS-02 confirms this feature…

High Energy Astrophysical Phenomena · Physics 2017-02-08 Behrouz Khiali , Sadakazu Haino , Jie Feng

We argue that the so called long flying component (LFC) observed in some cosmic ray experiments are yet another manifestation of L\'evy distributions (with index $q=1.3$), this time of the distribution observation probability of the depths…

High Energy Physics - Phenomenology · Physics 2009-10-31 G. Wilk , Z. Wlodarczyk

The Fermi-LAT collaboration recently confirmed a discrepancy between the observed longitudinal profile of gamma-ray diffuse emission from the Galaxy and that computed with numerical codes assuming that Cosmic Rays (CRs) are produced by…

High Energy Astrophysical Phenomena · Physics 2013-07-01 Daniele Gaggero , Carmelo Evoli , Dario Grasso , Luca Maccione

A common problem in ultra-high energy cosmic ray physics is the comparison of energy spectra. The question is whether the spectra from two experiments or two regions of the sky agree within their statistical and systematic uncertainties. We…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 S. Y. BenZvi , B. M. Connolly , C. G. Pfendner , S. Westerhoff

The analysis of cosmic rays fluxes as a function of energy reveals a {\it knee} slightly below $10^{16}$ eV and an {\it ankle} close to $10^{19}$ eV. Their physical origins remain up to now quite enigmatic; in particular, no elementary…

Astrophysics · Physics 2007-05-23 Constantino Tsallis , Joao C. Anjos , Ernesto P. Borges

Diffusion occurs in numerous physical systems throughout nature, drawing its generality from the universality of the central limit theorem. Around a century ago it was realized that an extension to this type of dynamics can be obtained in…

Statistical Mechanics · Physics 2023-10-04 Gadi Afek , Nir Davidson , David A. Kessler , Eli Barkai

We consider the diffuse gamma ray data from FERMI first year observations and compare them to the gamma ray fluxes predicted by Dark Matter annihilation or decay (both from prompt emission and from Inverse Compton Scattering), for different…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Marco Cirelli , Paolo Panci , Pasquale D. Serpico

We show that the positron excess measured by the PAMELA experiment in the region between 10 and 100 GeV may well be a natural consequence of the standard scenario for the origin of Galactic cosmic rays. The 'excess' arises because of…

High Energy Astrophysical Phenomena · Physics 2009-09-02 Pasquale Blasi

More than 100 years after the discovery of cosmic rays and various experimental efforts, the origin of ultra-high energy cosmic rays (E > 100 PeV) remains unclear. The understanding of production and propagation effects of these highest…

High Energy Astrophysical Phenomena · Physics 2014-09-23 Daniel Kuempel

After the breakthrough from the satellite-borne PAMELA detector, the flux of cosmic-ray (CR) antiprotons has been provided with unprecedented accuracy by AMS-02 on the International Space Station. Its data spans an energy range from below 1…

High Energy Astrophysical Phenomena · Physics 2018-06-05 Fiorenza Donato , Michael Korsmeier , Mattia Di Mauro

We calculate the diffuse $\gamma$-ray emission due to the population of misaligned AGN (MAGN) unresolved by the Large Area Telescope (LAT) on the {\it Fermi} Gamma-ray Space Telescope ({\it Fermi}). A correlation between the $\gamma$-ray…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-21 M. Di Mauro , F. Donato , F. Calore

We try to interpret the recently updated measurement of the cosmic ray electron (CRE) spectrum observed by Fermi-LAT, together with PAMELA data on positron fraction, in a single-component scenario adopting different propagation setups; we…

High Energy Astrophysical Phenomena · Physics 2022-03-02 Giuseppe Di Bernardo , Carmelo Evoli , Daniele Gaggero , Dario Grasso , Luca Maccione , Mario N. Mazziotta

Recent work suggests that the cosmic ray spectrum may be dominated by Galactic sources up to ~10^{17.5} eV, and by an extra-Galactic component beyond, provided this latter cuts off below the transition energy. Here it is shown that this…

Astrophysics · Physics 2009-11-10 Martin Lemoine

Observations of high energy gamma rays recently revealed a persistent source in spatial coincidence with the binary system Eta Carinae. Since modulation of the observed gamma-ray flux on orbital time scales has not been reported so far, an…

High Energy Astrophysical Phenomena · Physics 2012-08-14 K. Reitberger , O. Reimer , A. Reimer , M. Werner , K. Egberts , H. Takahashi

Analysis of data from the EGRET gamma-ray detector on the Compton Gamma Ray Observatory indicated an anomaly in the form of an excess diffuse galactic flux at GeV energies over that which was theoretically predicted. Various explanations…

Astrophysics · Physics 2009-06-23 F. W. Stecker , S. D. Hunter , D. A. Kniffen

After a short history of the $\Lambda$-term it is explained why the (effective) cosmological constant is expected to obtain contributions from short-distance physics, corresponding to an energy at least as large as the Fermi scale. The…

Astrophysics · Physics 2007-05-23 Norbert Straumann