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Related papers: Extreme scattering events and Galactic dark matter

200 papers

A recent re-analysis of EGRET data by Dixon et al. has led to the discovery of a statistically significant diffuse $\gamma$-ray emission from the galactic halo. We show that this emission can naturally be accounted for within a…

Astrophysics · Physics 2007-05-23 F. De Paolis , G. Ingrosso , Ph. Jetzer , M. Roncadelli

We present initial results from the first optical spectroscopic survey of high latitude Galactic cirrus clouds. The observed shape of the cirrus spectrum does not agree with that of scattered ambient Galactic starlight. This mismatch can be…

Astrophysics · Physics 2009-10-30 Arpad Szomoru , Puragra Guhathakurta

Extremely asymmetrical scattering (EAS) is an unusual type of Bragg scattering in slanted periodic gratings with the scattered wave (the +1 diffracted order) propagating parallel to the grating boundaries. Here, a unique and strong…

Optics · Physics 2007-05-23 D. K. Gramotnev , T. A. Nieminen , T. A. Hopper

UHE neutrinos may transfer highest cosmic-rays energies overcoming $2.75K^\circ$ BBR and radio-waves opacities (the GZK cut off) from most distant AGN sources at the age of the Universe. These UHE $\nu$ might scatter onto those (light and…

Astrophysics · Physics 2007-05-23 Daniele Fargion , Barbara Mele

A strong case has been made that radio waves from sources within about half a degree of the Galactic Center undergo extreme diffractive scattering. However, problems arise when standard (``Kolmogorov'') models of electron density…

Astrophysics · Physics 2009-11-11 Peter Goldreich , S. Sridhar

Observations with the Extreme Ultraviolet Explorer satellite are purported to show extreme ultraviolet (EUV) and soft X-ray excesses in several clusters of galaxies (Bonamente, Lieu & Mittaz 2001). If interpreted as thermal emission, this…

Astrophysics · Physics 2009-11-06 Philip R. Maloney , J. Bland-Hawthorn

Recently it was shown that the excess of diffuse Galactic gamma rays above 1 GeV traces the Dark Matter halo, as proven by reconstructing the peculiar shape of the rotation curve of our Galaxy from the gamma ray excess. This can be…

High Energy Physics - Phenomenology · Physics 2008-11-26 W. de Boer , C. Sander , V. Zhukov , A. V. Gladyshev , D. I. Kazakov

We present hydrostatic equilibrium models of spherical, self-gravitating clouds of helium and molecular hydrogen, focusing on the cold, high-density regime where solid- or liquid-hydrogen can form. The resulting structures have masses from…

Astrophysics of Galaxies · Physics 2019-08-21 Mark Walker , Mark Wardle

We demonstrate that ionization of $\text{H}_2$ by dark matter in dense molecular clouds can provide strong constraints on the scattering strength of dark matter with electrons. Molecular clouds have high UV-optical attenuation, shielding…

High Energy Physics - Phenomenology · Physics 2023-08-28 Anirudh Prabhu , Carlos Blanco

Absence of the signals of the physics beyond the Standard Model at the available LHC energies means that the several of cosmic data peculiarities could be associated with an emergency of the new scattering mode. This reflective scattering…

High Energy Physics - Phenomenology · Physics 2015-04-23 S. M. Troshin , N. E. Tyurin

We discuss recent models in which neutrinos, which are assumed to have mass in the eV range, originate the highest energy cosmic rays by interaction with the enhanced density in the galactic halo of the relic cosmic neutrino background. We…

Astrophysics · Physics 2009-10-31 J. J. Blanco-Pillado , R. A. Vázquez , E. Zas

The decay of very heavy metastable relics of the Early Universe can produce ultra-high energy cosmic rays (UHECRs) in the halo of our own Galaxy. On distance scales of the order of the halo size, energy losses are negligible---no…

Astrophysics · Physics 2011-08-23 Pasquale Blasi , Ravi Sheth

The diffused gamma halo around our Galaxy recently discovered by EGRET could be produced by annihilations of relic neutrinos N (of fourth generation), whose mass is within a narrow range (Mz /2 < M < Mz). Neutrino annihilations in the halo…

Astrophysics · Physics 2009-10-30 Daniele Fargion , Rostislav Konoplich , Marco Grossi , Maxim Khlopov

Particle dark matter scattering on electrons in the Sun may gravitationally capture and self-annihilate inside it to neutrinos and anti-neutrinos, or other final states that in turn decay to them. Using up-to-date measurements by…

High Energy Physics - Phenomenology · Physics 2025-03-19 Dhashin Krishna , Rinchen Sherpa , Akash Kumar Saha , Tarak Nath Maity , Ranjan Laha , Nirmal Raj

Extreme coronal line emitters (ECLEs) are objects showing transient high-ionization lines in the centers of galaxies. They have been attributed to echoes of high-energy flares of ionizing radiation, such as those produced by tidal…

We present a theoretical study of elastic spin-dependent electron scattering caused by a charged impurity in the vicinity of a two-dimensional electron gas. We find that the symmetry properties of the spin-dependent differential scattering…

Mesoscale and Nanoscale Physics · Physics 2009-01-05 A. Pályi , J. Cserti

Relativistic electron losses in Earth's radiation belts are usually attributed to electron resonant scattering by electromagnetic waves. One of the most important wave mode for such scattering is the electromagnetic ion cyclotron (EMIC)…

We discuss the possibility that the recent detection of 511 keV gamma rays from the galactic bulge, as observed by INTEGRAL, can be naturally explained by the supermassive very dense droplets (strangelets) of dark matter. These droplets are…

High Energy Physics - Phenomenology · Physics 2009-11-10 David H. Oaknin , Ariel R. Zhitnitsky

(Abridged) High-E electrons produce Hard X-Ray (HXR) emission in galaxy clusters by via Inverse Compton Scattering (ICS) of CMB photons. We derive the ICS HXR emission of Ophiuchus under various scenarios: primary cosmic ray model,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 S. Colafrancesco , P. Marchegiani