Related papers: Do Cosmic Rays Heat the Early Intergalactic Medium…
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…
A definite prediction from recent N-body/hydro simulations of the structure formation of the universe is the presence of a diffuse intergalactic medium (IGM) in a temperature range of 10^5 - 10^7 K. This hot phase of the IGM may account for…
The problem in identifying the sites of origin of Galactic Cosmic Rays (CRs) is reviewed. Recent observational evidence from very-high energy (VHE, energies above 100 GeV) gamma-ray measurements is in contradiction with the surmise that…
A model is proposed for the origin of cosmic rays (CRs) from ~10^14 eV to the highest energies, >10^20 eV. Gamma-Ray Bursts (GRBs) are assumed to inject CR protons and ions into the interstellar medium of star-forming galaxies--including…
The detection of high-energy particles, cosmic rays (CRs), deep inside the heliosphere implies that there are, at least, three distinctly different stages in the lifetime of a CR particle: acceleration, propagation in the interstellar…
Cosmic rays (CRs) play a pivotal role in shaping the thermal and dynamical properties of astrophysical environments, such as galaxies and galaxy clusters. Recent observations suggest a stronger confinement of CRs in certain astrophysical…
Self-regulating AGN feedback in the cool cores of galaxy clusters plays central role in solving the decades-old cooling flow problem, but one major problem remains unsolved - how is the AGN energy thermalized in the ICM and what are the…
The intergalactic medium was reionized before redshift z~6, most likely by starlight which escaped from early galaxies. The very first stars formed when hydrogen molecules (H2) cooled gas inside the smallest galaxies, minihalos of mass…
Cluster spiral galaxies suffer catastrophic losses of the cool, neutral gas component of their interstellar medium due to ram pressure stripping, contributing to the observed quenching of star formation in the disk compared to galaxies in…
Star-forming galaxies (SFGs) have been established as an important source population in the extra-galactic $\gamma$-ray background (EGB). Their intensive star-formation creates an abundance of environments able to accelerate particles, and…
Several lines of evidence point to a relationship between gamma-ray bursts (GRBs) and the high mass stars that explode as supernovae. Arguments that GRB sources accelerate cosmic rays (CRs) are summarized. High-energy neutrino detection…
Cosmic-rays constitute the main ionising and heating agent in dense, starless, molecular cloud cores. We reexamine the physical quantities necessary to determine the cosmic-ray ionisation rate (especially the cosmic ray spectrum at E < 1…
We investigate the dynamical impact of cosmic rays in cosmological simulations of galaxy formation using adaptive-mesh refinement simulations of a $10^{12}$ solar mass halo. In agreement with previous work, a run with only our standard…
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…
During reionization, the intergalactic medium is heated impulsively by supersonic ionization fronts (I-fronts). The peak gas temperatures behind the I-fronts, $T_\mathrm{reion}$, are a key uncertainty in models of the thermal history after…
The Central Molecular Zone (CMZ), located in the centre of the Milky Way, is a roughly cylindrical structure of molecular gas extending up to parsecs around the supermassive black hole Sagittarius A*. The average H2 ionisation rate in the…
The physical characteristics of the Lyman-alpha forest cloud systems are combined with observations on the baryonic mass density of the Universe and constraints from primordial nucleosynthesis to set boundary conditions on the Intergalactic…
The contribution of the Source Cosmic Rays (SCRs), confined in Supernova Remnants, to the diffuse high energy \gr emission above 1 GeV from the Galactic disk is studied. \grs produced by the SCRs have a much harder spectrum compared with…
Cosmic rays (CR) play an important role in dense molecular cores, affecting their thermal and dynamical evolution and initiating the chemistry. Several studies have shown that the formation of protostellar discs in collapsing clouds is…
The hot circum-galactic medium (CGM) represents the hot gas distributed beyond the stellar content of the galaxies while typically within their dark matter halos. It serves as a depository of energy and metal-enriched materials from…