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Related papers: Cosmic Rays Masquerading as Cool Cores: An Inverse…

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X-ray luminous cool-core (CC) galaxy clusters contain powerful cosmic ray (CR) sources. High-energy CRs powering GHz synchrotron lose energy rapidly, but long-lived (~Gyr-old) populations of 0.1-1 GeV CRs persist, propagating to ~100 kpc…

High Energy Astrophysical Phenomena · Physics 2026-02-02 Philip F. Hopkins , Emily Silich , Jack Sayers , Sam B. Ponnada , Isabel Sands

Observations have argued that Milky Way (MW), Andromeda, and lower-mass galaxies exhibit extended soft X-ray diffuse halos to radii $R\gtrsim100\,$kpc in the circumgalactic medium (CGM). If interpreted as thermal emission, the shallow…

High Energy Astrophysical Phenomena · Physics 2025-12-22 Philip F. Hopkins , Eliot Quataert , Sam B. Ponnada , Emily Silich

We study non-thermal emissions from cool cores in galaxy clusters. We adopted a recent model, in which cosmic-rays (CRs) prevail in the cores and stably heat them through CR streaming. The non-thermal emissions come from the interaction…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Yutaka Fujita , Yutaka Ohira

We explore the possibility that inverse-Compton (IC) scattering of cosmic microwave background photons by $\sim$GeV cosmic rays (CRs) injected by the central active galactic nucleus (AGN) in cool core (CC) clusters produces a non-negligible…

High Energy Astrophysical Phenomena · Physics 2025-10-17 Emily M. Silich , Jack Sayers , Philip F. Hopkins , Charles Romero , Brian Mason , John Orlowski-Scherer , Craig L. Sarazin

Perseus is the brightest X-ray strong cool-core (SCC) cluster, with a bright central radio and $\gamma$-ray source plus low-frequency radio mini and giant halos. It is the archetype of the cooling flow (CF) problem, with X-rays implying…

High Energy Astrophysical Phenomena · Physics 2026-05-12 Philip F. Hopkins , Emily M. Silich , Jack Sayers , Sam B. Ponnada , Isabel S. Sands

It has been proposed that the cool cores of galaxy clusters are stably heated by cosmic rays (CRs). If this is the case, radio mini-halos, which are often found in the central regions of cool core clusters, may be attributed to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Yutaka Fujita , Yutaka Ohira

The role of cosmic rays (CR) in the formation and evolution of clusters of galaxies has been much debated. It may well be related to other fundamental questions, such as the mechanism which heats and virializes the intracluster medium…

Astrophysics · Physics 2009-10-30 R. Lieu , W. -H. Ip , W. I. Axford , M. Bonamente

We investigate the spatial and spectral properties of non-thermal emission from clusters of galaxies at gamma-ray energies between 10 keV and 10 TeV due to inverse-Compton (IC) emission, pion-decay and non-thermal bremsstrahlung (NTB) from…

Astrophysics · Physics 2009-11-07 Francesco Miniati

Chandra images of galaxy clusters have revealed a wealth of structure unseen by previous generations of low resolution X-ray observatories. In the cores of clusters, bright, irregular X-ray emission is now routinely seen within central…

Astrophysics · Physics 2007-05-23 B. R. McNamara

We report the detection of extended X-ray emission around two powerful high-z radio galaxies (HzRGs) at z~3.6 (4C03.24 & 4C19.71) and use these to investigate the origin of extended, Inverse Compton (IC) powered X-ray halos at high z. The…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Ian Smail , Katherine M. Blundell , B. D. Lehmer , D. M. Alexander

The radiative cooling time of the X-ray-emitting plasma near the center in many clusters of galaxies is shorter than the age of the cluster, but neither the expected large drop in central temperature --nor the expected mass flow towards the…

Astrophysics · Physics 2009-11-07 Sergio Colafrancesco , Arnon Dar , Alvaro De Rujula

Cluster cool cores possess networks of line-emitting filaments. These filaments are thought to originate via uplift of cold gas from cluster centers by buoyant active galactic nuclei (AGN) bubbles, or via local thermal instability in the…

High Energy Astrophysical Phenomena · Physics 2018-06-06 Mateusz Ruszkowski , H. -Y. Karen Yang , Christopher S. Reynolds

We present a model of cosmic ray heating of clusters' cores that reproduces the observed temperature distribution in clusters by using an energy balance condition in which the emitted X-ray energy is supplied by the hadronic cosmic rays,…

Astrophysics · Physics 2009-11-13 S. Colafrancesco , P. Marchegiani

We suggest that the luminous extreme ultraviolet (EUV) emission which has been detected recently from clusters of galaxies is Inverse Compton (IC) scattering of Cosmic Microwave Background (CMB) radiation by low energy cosmic ray electrons…

Astrophysics · Physics 2009-10-30 Craig L. Sarazin , Richard Lieu

We calculate the flux of radio, hard X-ray and UV radiation from clusters of galaxies as produced by synchrotron emission and Inverse Compton Scattering of electrons generated as secondaries in cosmic ray interactions in the intracluster…

Astrophysics · Physics 2011-08-09 P. Blasi , S. Colafrancesco

Coronal hard X-ray (HXR) and continuum gamma-ray sources associated with the impulsive phase of solar flares have been the subject of renewed interest in recent years. They have been interpreted in terms of thin-target, nonthermal…

Solar and Stellar Astrophysics · Physics 2015-05-30 Bin Chen , Timothy S. Bastian

We calculate the fluxes of radio, hard X-rays and gamma-ray emission from clusters of galaxies, in the context of a secondary electron model (SEM). In the SEM the radiating electrons are produced by the decay of charged pions in cosmic ray…

Astrophysics · Physics 2007-05-23 P. Blasi , S. Colafrancesco

We show that Compton scattering by electrons of the hot intergalactic gas in galaxy clusters should lead to peculiar distortions of the cosmic background X-ray and soft gamma-ray radiation - an increase in its brightness at E<60-100 keV and…

High Energy Astrophysical Phenomena · Physics 2020-04-23 S. A. Grebenev , R. A. Sunyaev

We present a definitive assessment of the role of Inverse Compton scattering of Cosmic Microwave Background photons (IC/CMB) in the context of radio galaxies. Owing to the steep increase of the CMB radiation energy density, IC/CMB is…

High Energy Astrophysical Phenomena · Physics 2021-05-26 Edmund Hodges-Kluck , Elena Gallo , Gabriele Ghisellini , Francesco Haardt , Jianfeng Wu , Benedetta Ciardi

The observed bimodality in radio luminosity in galaxy clusters is puzzling. We investigate the possibility that cosmic-ray (CR) streaming in the intra-cluster medium can 'switch off' hadronically induced radio and gamma-ray emission. For…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Joshua Wiener , S Peng Oh , Fulai Guo
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