相关论文: The magnetized galactic wind and synchrotron halo …
HI observations of the nearby blue compact dwarf galaxy IC 10 obtained with the Dominion Radio Astrophysical Observatory synthesis telescope (DRAO), for a total integration of $\sim$1000 hours, are presented. We confirm the NW faint 21 cm…
We study the characteristic size and shape of idealized blazar-induced cascade halos in the $1-100 \, {\rm GeV}$ energy range assuming various non-helical and helical configurations for the intergalactic magnetic field (IGMF). While the…
Starburst galaxies are generally associated with extended X-ray and radio halos, giving a clear hint of an outflow of gas and relativistic particles from the disk into the halo. The driving agents are, not surprisingly, active star forming…
Aims. To study at multiple frequencies the radio emission arising from the massive galaxy cluster MACS J0717.5+3745 (z=0.55). Known to be an extremely complex cluster merger, the system is uniquely suited for an investigation of the…
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…
Radio synchrotron emission is a powerful tool to study the strength and structure of magnetic fields in galaxies. Unpolarized synchrotron emission traces isotropic turbulent fields which are strongest in spiral arms and bars (20-30 \mu G)…
We present submillimeter observations of the Local Group, metal-poor, irregular dwarf galaxy IC 10, directly relevant to the interaction between interstellar medium and star formation activity in primeval galaxies. Using the JCMT, we have…
A quantitative analysis of two radio source samples having opposite extremes of ambient gas density leads to important new conclusions about the magnetic energy in the IGM. We conclude that giant sources in rarefied IGM environments, which…
Some galaxy clusters show diffuse radio emission in the form of giant halos (GHs) on Mpc scales or minihalos (MHs) on smaller scales. Comparing VLA and XMM radial profiles of several such clusters, we find a universal linear correlation…
Annihilation of Dark Matter usually produces together with gamma rays comparable amounts of electrons and positrons. The e+e- gyrating in the galactic magnetic field then produce secondary synchrotron radiation which thus provides an…
Gravitational waves (GW) propagating through a magnetised plasma excite low-frequency magnetohydrodynamic (MHD) waves. In this paper we investigate whether these waves can produce observable radio emission at higher frequencies by…
The composition and morphology of the interstellar medium in starburst galaxies has been well investigated, but the magnetic field properties are still uncertain. The nearby starburst galaxy M82 provides a unique opportunity to investigate…
We describe a first attempt to derive properties of the regular and turbulent Galactic magnetic field from multi-frequency polarimetric observations of the diffuse Galactic synchrotron background. A single-cell-size model of the thin…
Galactic outflows driven by starbursts can modify the galactic magnetic fields and drive them away from the galactic planes. Here, we quantify how these fields may magnetize the intergalactic medium. We estimate the strength and structure…
Observations of metal lines in $\lyal$ absorption systems of small H~I column density and their ubiquitous nature suggest that the intergalactic medium (IGM) was enriched to about $Z \sim 0.01 \> Z_{\odot}$ by a redshift $z \sim 3$. We…
Dark matter annihilations in the Galactic halo inject relativistic electrons and positrons which in turn generate a synchrotron radiation when interacting with the galactic magnetic field. We calculate the synchrotron flux for various dark…
Defined as the magnetic field permeating cosmic voids, the Intergalactic Magnetic Field (IGMF) is thought to be a relic of the Big Bang, tracing a primordial magnetic seed at the origin of all astrophysical fields. Yet, it has thus far…
From our radio continuum and polarization observations of a sample of spiral galaxies with different morphological types, inclinations, and star formation rates (SFR) we found that galaxies with low SFR have higher thermal fractions/…
Intergalactic magnetic fields (IGMF) can cause the appearance of halos around the gamma-ray images of distant objects because an electromagnetic cascade initiated by a high-energy gamma-ray interaction with the photon background is…
We present a model for the seeding and evolution of magnetic fields in protogalaxies. Supernova (SN) explosions during the assembly of a protogalaxy provide magnetic seed fields, which are subsequently amplified by compression, shear flows…