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Related papers: Evidence for a Galactic gamma ray halo

200 papers

The diffuse galactic EGRET gamma ray data show a clear excess for energies above 1 GeV in comparison with the expectations from conventional galactic models. The excess is seen with the same spectrum in all sky directions, as expected for…

High Energy Physics - Phenomenology · Physics 2009-11-10 W. de Boer

Fast radio bursts offer the opportunity to place new constraints on the mass and density profile of hot and ionized gas in galactic haloes. We test here the X-ray emission and dispersion measure predicted by different gas profiles for the…

Astrophysics of Galaxies · Physics 2020-06-03 Laura C. Keating , Ue-Li Pen

The study of Galactic diffuse $\gamma$ radiation combined with the knowledge of the distribution of the molecular hydrogen in the Galaxy offers a unique tool to probe the cosmic ray flux in the Galaxy. A methodology to study the level of…

Astrophysics · Physics 2009-11-13 S. Casanova , S. Gabici , F. A. Aharonian , K. Torii , Y. Fukui , T. Onishi , H. Yamamoto , A. Kawamura

Recent progress in pushing the sensitivity of the Imaging Atmospheric Cherenkov Technique into the 10 mCrab regime has enabled first sensitive observations of the innermost few 100 pc of the Milky Way in Very High Energy (VHE; >100 GeV)…

Astrophysics · Physics 2009-11-13 Christopher van Eldik

The dark matter halo profile in the inner Galaxy is very uncertain. Yet its radial dependence toward the Galactic Center is of crucial importance for the determination of the gamma-ray and radio fluxes originating from dark matter…

High Energy Astrophysical Phenomena · Physics 2014-04-04 Thomas Lacroix , Celine Boehm , Joseph Silk

The Milky Way galaxy is surrounded by a circumgalactic medium (CGM) that may play a key role in galaxy evolution as the source of gas for star formation and a repository of metals and energy produced by star formation and nuclear activity.…

Astrophysics of Galaxies · Physics 2020-11-03 P. Kaaret , D. Koutroumpa , K. D. Kuntz , K. Jahoda , J. Bluem , H. Gulick , E. Hodges-Kluck , D. M. LaRocca , R. Ringuette , A. Zajczyk

We use 666 blue horizontal branch (BHB) stars from the 2Qz redshift survey to map the Galactic halo in four dimensions (position, distance and velocity). We find that the halo extends to at least 100 kpc in Galactocentric distance, and…

Astrophysics of Galaxies · Physics 2015-05-19 Roberto De Propris , Craig D. Harrison , Peter J. Mares , CTIO , Cornell University

The diffuse gamma-ray sky revealed 'Bubbles' of emission above and below the Galactic Plane symmetric around the centre of the Milky Way with a height of 10 kpc in both directions. At present there is no convincing explanation for the…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Wim de Boer , Markus Weber

The GALPROP model for cosmic-ray propagation is able to make explicit predictions for the distribution of galactic diffuse gamma-rays. We compare different propagation models with gamma-ray spectra measured by EGRET for various regions of…

Astrophysics · Physics 2009-11-11 Andrew W. Strong , Igor V. Moskalenko , Olaf Reimer

The third EGRET catalog contains a large number of unidentified sources. This subset of objects is expected to include known gamma-ray emitters of Galactic origin such as pulsars and supernova remnants, in addition to an extragalactic…

Astrophysics · Physics 2009-03-26 J. M. Siegal-Gaskins , V. Pavlidou , A. V. Olinto , C. Brown , B. D. Fields

We investigate if the gamma ray halo, for which recent evidence has been found in EGRET data, can be explained by neutralino annihilations in a clumpy halo. We find that the measured excess gamma ray flux can be explained through a moderate…

Astrophysics · Physics 2009-10-30 L. Bergstrom , J. Edsjo , P. Ullio

We address the role of gamma-ray astronomy in the investigation of nonthermal processes in the large scale structure of the universe. Based on EGRET upper limits on nearby galaxy clusters (GCs) we constrain the acceleration efficiency of CR…

Astrophysics · Physics 2007-05-23 Francesco Miniati

We analyze an adaptive mesh refinement hydrodynamic cosmological simulation of a Milky Way-sized galaxy to study the cold gas in the halo. HI observations of the Milky Way and other nearby spirals have revealed the presence of such gas in…

Astrophysics of Galaxies · Physics 2015-06-04 Ximena Fernández , M. Ryan Joung , Mary E. Putman

The halo of the Milky-Way circumgalactic gas extends up to the virial radius of the Galaxy, ~250 kpc. The halo properties may be deduced from X-ray spectroscopic observations and from studies of the ram-pressure stripping of satellite dwarf…

Astrophysics of Galaxies · Physics 2017-03-07 Sergey Troitsky

If the diffuse extragalactic gamma ray emission traces the large scale structures of the universe, peculiar anisotropy patterns are expected in the gamma ray sky. In particular, because of the cutoff distance introduced by the absorption of…

Astrophysics · Physics 2014-10-13 A. Cuoco , S. Hannestad , T. Haugbølle , G. Miele , P. D. Serpico , H. Tu

The wealth of data in the past decades, and especially in the past 15 years has transformed our picture of the gas around the Milky Way and other spiral galaxies. There is good evidence for extraplanar gas that is a few kpc in height and is…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-22 Joel N. Bregman

Many star-forming galaxies and those hosting active galactic nuclei (AGN) show evidence of massive outflows of material in a variety of phases including ionized, neutral atomic, and molecular. Molecular outflows in particular have been the…

High Energy Astrophysical Phenomena · Physics 2023-02-15 Alex McDaniel , Marco Ajello , Chris Karwin

A population of discrete HI clouds in the halo of the inner Galaxy has been discovered in 21cm observations made with the Green Bank Telescope. The halo clouds are seen up to 1.5 kpc from the Galactic plane at many longitudes. Their…

Astrophysics · Physics 2009-11-07 Felix J. Lockman

A wealth of recent studies have shown that the LMC is likely massive, with a halo mass $>10^{11} M_\odot$. One consequence of having such a nearby and massive neighbour is that the inner Milky Way is expected to be accelerated with respect…

We present a deep XMM-Newton observation of the Galactic halo emission in the direction of the blazar 1ES 1553+113. In order to extract the Galactic halo component from the diffuse soft X-ray emission spectrum, accurately modeling the…

Astrophysics of Galaxies · Physics 2020-07-23 Sanskriti Das , Smita Mathur , Anjali Gupta , Fabrizio Nicastro , Yair Krongold
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