相关论文: Cosmic Rays and Non-Thermal Emission in Galaxy Clu…
Clusters of galaxies are revealing themselves as powerful sources of non thermal radiation in a wide range of wavelengths. In order to account for these multifrequency observations equipartition of cosmic rays (CRs) with the thermal gas in…
(Abridged) We study the predictions of various annihilating Dark Matter (DM) models in order to interpret the origin of non-thermal phenomena in galaxy clusters. We consider three neutralino DM models with light (9 GeV), intermediate (60…
Massive stars form in dense and massive molecular cores. The exact formation mechanism is unclear, but it is possible that some massive stars are formed by processes similar to those that produce the low-mass stars, with accretion/ejection…
A very important aspect of the radio emission from galaxy clusters is represented by the diffuse radio sources associated with the intracluster medium: radio halos and relics. These radio sources indicate the existence of large scale…
High velocity clouds moving toward the disk will reach the Galactic plane and will inevitably collide with the disk. In these collisions a system of two shocks is produced, one propagating through the disk and the other develops within the…
Galaxy clusters (GCs) are the largest and most massive gravitationally bound objects in the large-scale structure of the Universe. Due to keV temperatures of virialized gas in the intracluster medium (ICM) and presence of cosmic rays (CRs),…
This lecture is an introduction to cosmological tests with clusters of galaxies. Here I do not intend to provide a complete review of the subject, but rather to describe the basic procedures to set up the fitting machinery to constrain…
Recent radio observations support a picture for star formation where there is accretion of matter onto a central protostar with the ejection of molecular outflows that can affect the surrounding medium. The impact of a supersonic outflow on…
Analyses of Chandra's first images of cooling flow clusters find smaller cooling rates than previously thought. Cooling may be occurring preferentially near regions of star formation in central cluster galaxies, where the local cooling and…
Very recently, a possible clustering of a subset of observed ultrahigh energy cosmic rays above about 40EeV (4x10^19eV) in pairs near the supergalactic plane was reported. We show that a confirmation of this effect would provide information…
Cosmic rays (CRs) interact with the gas, the radiation field and the magnetic field in the Milky Way, producing diffuse emission from radio to gamma rays. Observations of this diffuse emission and comparison with detailed predictions are…
We compare the nonthermal emission from clusters of galaxies undergoing minor mergers (``accreting'' clusters) and major mergers (``merging'' clusters). For accreting clusters, the radial distribution of the nonthermal emission in the…
Recent observations have revealed the existence of enormously energetic ~10^61 erg AGN outbursts in three relatively distant galaxy clusters. These outbursts have produced bubbles in the intra-cluster medium, apparently supported by…
One way to understand the nonthermal history of the universe is by establishing the origins of the unresolved and truly diffuse extragalactic gamma rays. Dim blazars and radio/gamma galaxies certainly make an important contribution to the…
This short paper reviews some of the results obtained from ISO observations (ISOCAM and ISOPHOT) on galaxy clusters: Chap.1: "Intracluster dust": new evidence for the presence of dust outside galaxies. Chap.2:"Mid-Infrared Emission of…
The last decade has been dense with new developments in the search for the sources of Galactic cosmic rays. Some of these developments have confirmed the tight connection between cosmic rays and supernovae in our Galaxy, through the…
We present a theory of non-solar cosmic rays (CRs) in which the bulk of their observed flux is due to a single type of CR source at all energies. The total luminosity of the Galaxy, the broken power-law spectra with their observed slopes,…
Multi-frequency (X-ray, optical and radio) observations of galaxy clusters indicate that the atmospheres of these cosmic structures consist of a complex structure of thermal (hot and warm) and non-thermal (with different origin and spectra)…
The Galactic center region near l$\approx0.2^0$ hosts a mixture of nonthermal linear filaments and thermal radio continuum features associated with the radio Arc. Chandra observations of this region reveal an X-ray filament and diffuse…
Galaxy clusters are the most massive gravitationally bound structures in the Universe. Even if clusters are nearly virialized structures, they undergo merging processes, creating merging shocks, and suffer from feedback from galaxies and…