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The synchrotron radio morphology of bilateral supernova remnants depends on the mechanisms of particle acceleration and on the viewing geometry. However, unlike X-ray and $\gamma$-ray morphologies, the radio emission does not depend on the…

High Energy Astrophysical Phenomena · Physics 2015-05-28 F. Bocchino , S. Orlando , M. Miceli , O. Petruk

Results of a simulation of synchrotron-self Compton (SSC) emission from a rotation-powered pulsar are presented. The radiating particles are assumed to be both accelerated primary electrons and a spectrum of electron-positron pairs produced…

High Energy Astrophysical Phenomena · Physics 2015-09-30 Alice K. Harding , Constantinos Kalapotharakos

We set limits on the presence of the synchrotron cosmic web through the cross-correlation of the 2.3 GHz S-PASS survey with a model of the local cosmic web derived from constrained magnetohydrodynamic (MHD) simulations. The MHD simulation…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-10 S. Brown , T. Vernstrom , E. Carretti , K. Dolag , B. M. Gaensler , L. Staveley-Smith , G. Bernardi , M. Haverkorn , M. Kesteven , S. Poppi

Empirical simulations based on extrapolations from well-established low-frequency ($< 5$ GHz) surveys fail to accurately model the faint, high frequency ($>10$~GHz) source population; they under-predict the number of observed sources by a…

Astrophysics of Galaxies · Physics 2017-08-16 Imogen H. Whittam , Matt J. Jarvis , David A. Green , Ian Heywood , Julia M. Riley

We present images of the Sagittarius (Sgr) B giant molecular cloud at 2368 and 1384 MHz obtained using new, multi-configuration Australia Telescope Compact Array (ATCA) observations. We have combined these observations with archival…

Astrophysics of Galaxies · Physics 2011-02-08 David I. Jones , Roland M. Crocker , Juergen Ott , Raymond J. Protheroe , Ron D. Ekers

Observations of diffuse, non-thermal radio emission spanning several megaparsecs have been documented in over 100 galaxy clusters. This emission, classified as giant radio halos (GHs), mini halos, and radio relics based mainly on their…

High Energy Astrophysical Phenomena · Physics 2024-04-23 Doron Kushnir , Uri Keshet , Eli Waxman

Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated, suggesting that clusters may also be sources of very high-energy (VHE; E>100 GeV) gamma-ray…

We generate probabilistic predictions of the low-redshift ($z < 0.2$) synchrotron Cosmic Web for half of the Northern Sky. In particular, we predict the contribution to the specific intensity function at $\nu_\mathrm{obs} = 150\…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 Martijn S. S. L. Oei , Reinout J. van Weeren , Franco Vazza , Florent Leclercq , Akshatha Gopinath , Huub J. A. Röttgering

Observations of anisotropies in the brightness temperature of the 21 cm line of neutral hydrogen from the period before reionization would shed light on the dawn of the first stars and galaxies. In this paper, we use large-scale…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-16 M. G. Santos , M. B. Silva , J. R. Pritchard , R. Cen , A. Cooray

Secondary positrons produced inside Galactic Molecular Clouds (GMCs) can significantly contribute to the observed positron spectrum on Earth. Multi-wavelength data of GMCs are particularly useful in building this model. A very recent survey…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Agnibha De Sarkar , Sayan Biswas , Nayantara Gupta

Non-thermal radio emission from cosmic ray electrons in the vicinity of merging galaxy clusters is an important tracer of cluster merger activity, and is the result of complex physical processes that involve magnetic fields, particle…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Samuel W. Skillman , Hao Xu , Eric J. Hallman , Brian W. O'Shea , Jack O. Burns , Hui Li , David C. Collins , Michael L. Norman

Bodies such as planets, moons, and asteroids in our solar system are the brightest objects in the low-frequency radio astronomy at $\lesssim$ 10 GHz. The low-frequency radio emissions from our solar system bodies exhibit various observed…

Earth and Planetary Astrophysics · Physics 2023-03-15 Tomoki Kimura , Yuka Fujii , Hajime Kita , Fuminori Tsuchiya , Hideo Sagawa , the SKA-Japan Planetary Science Team

The presence of magnetic fields in galaxy clusters has been well established in recent years, and their importance for the understanding of the physical processes at work in the Intra Cluster Medium has been recognized. Halo and relic…

We investigate the possibility for the SKA to detect and study the magnetic fields in galaxy clusters and in the less dense environments surrounding them using Faraday Rotation Measures. To this end, we produce 3-dimensional magnetic field…

The strength of the total magnetic field in our Milky Way from radio Zeeman and synchrotron measurements is about 6 muG near the Sun and several mG in dense clouds, pulsar wind nebulae, and filaments near the Galactic Center. Diffuse…

Astrophysics · Physics 2009-11-13 Rainer Beck

21cm intensity mapping experiments aim to observe the diffuse neutral hydrogen (HI) distribution on large scales which traces the Cosmic structure. The Square Kilometre Array (SKA) will have the capacity to measure the 21cm signal over a…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-19 Laura Wolz , Filipe B. Abdalla , David Alonso , Chris Blake , Philip Bull , Tzu-Ching Chang , Pedro G. Ferreira , Cheng-Yu Kuo , Marios G. Santos , Richard Shaw

If we try to measure the backward optical diffraction radiation (BODR) of high energy electrons from a conductive slit or a semi infinitive plate, the electron beam will pass thru the bending or steering magnets or magnet lenses before…

Accelerator Physics · Physics 2009-11-07 G. A. Naumenko

Deep surveys with the SKA1-MID array offer for the first time the opportunity to systematically explore the polarization properties of the microJy source population. Our knowledge of the polarized sky approaching these levels is still very…

The guiding center formalism is employed to analyze the motion of a charged relativistic particle in an inhomogeneous magnetic field, subject to magnetic mirroring and energy loss due to cooling. The governing equation for the evolution of…

High Energy Astrophysical Phenomena · Physics 2026-04-17 Mikhail V. Medvedev , Anatoly Spitkovsky , Alexander Philippov

Given the multiple energy loss mechanisms of cosmic ray electrons in galaxies, the tightness of the infrared - radio continuum correlation is surprising. We extended the analytical model of galactic disks of Vollmer et al. (2017) by…

Astrophysics of Galaxies · Physics 2022-11-02 B. Vollmer , M. Soida , J. Dallant