Related papers: Evidence for Cosmic-Ray Escape in the Small Magell…
Feedback processes in galaxies dictate their structure and evolution. Baryons can be cycled through stars, which inject energy into the interstellar medium (ISM) in supernova explosions, fueling multiphase galactic winds. Cosmic rays (CRs)…
Observations of diffuse radio emission in galaxy clusters indicate that cosmic-ray electrons are accelerated on $\sim$Mpc scales. However, protons appear to be accelerated less efficiently since their associated hadronic $\gamma$-ray…
Cosmic rays (CRs) have recently re-emerged as attractive candidates for mediating feedback in galaxies because of their long cooling timescales. They can have energy densities comparable to the thermal gas, but do not suffer catastrophic…
Motivated by the discovery of the non-thermal Fermi bubble features both below and above the Galactic plane, we investigate a scenario in which these bubbles are formed through Galacto-centric outflow. Cosmic rays (CR) both diffusing and…
We study the effects of escaping cosmic rays (CRs) on the interstellar medium (ISM) around their source with spherically symmetric CR-hydrodynamical simulations taking into account the evolution of the CR energy spectrum, radiative cooling,…
We study the propagation of mildly-relativistic cosmic rays (CRs) in multiphase interstellar medium environments with conditions typical of nearby disk galaxies. We employ the techniques developed in Armillotta+21 to post-process three…
Latest precise cosmic-ray (CR) measurements and present gamma-ray observations have started challenging our understanding of CR transport and interaction in the Galaxy. Moreover, because the density of CRs is similar to the density of the…
We study a scenario in which the Fermi bubbles are formed through a Galactocentric outflow of gas and pre-accelerated cosmic-rays (CR). We take into account CR energy losses due to proton-proton interactions with the gas present in the…
We study the gamma-ray spectra of 30 globular clusters (GCs) thus far detected with the Fermi Gamma-ray Space Telescope. Presuming that gamma-ray emission of a GC comes from millisecond pulsars (MSPs) contained in, a model that generates…
Cosmic-ray (CR) sources temporarily enhance the relativistic particle density in their vicinity over the background distribution accumulated from the Galaxy-wide past injection activity and propagation. If individual sources are close…
Cosmic ray (CR) feedback in galaxy evolution has seen a theoretical resurgence in the past decade, but significant uncertainties remain in CR transport through the interstellar and circum-galactic media (ISM and CGM). While several works…
Dynamically, cosmic rays with energies above about one GeV/nucleon may be important agents of galaxy evolution. Their pressures compare with the thermal and magnetic ones impacting galactic gas accretion, fountains and galactic outflows,…
Starburst galaxies are efficient $\gamma$-ray producers, because their high supernova rates generate copious cosmic ray (CR) protons, and their high gas densities act as thick targets off which these protons can produce neutral pions and…
Cosmic rays (CRs) and magnetic fields may be dynamically important in driving large-scale galactic outflows from rapidly star-forming galaxies. We construct two-dimensional axisymmetric models of the local starburst and super-wind galaxy…
The optical and near-IR emission from some classes of supernovae (SNe), including Type IIn and possibly some super-luminous SNe, is likely powered by a collision between the SN ejecta and dense circumstellar material (CSM). We argue that…
Recently, gamma-ray telescopes AGILE and Fermi observed several middle-aged supernova remnants (SNRs) interacting with molecular clouds. It is likely that their gamma rays arise from the decay of neutral pions produced by the inelastic…
We compute the contribution from clusters of galaxies to the diffuse neutrino and $\gamma-$ray background. Due to their unique magnetic-field configuration, cosmic rays (CRs) with energy $\leq10^{17}$ eV can be confined within these…
The {\it Fermi} Large Area Telescope has recently discovered two giant gamma-ray bubbles which extend north and south of the Galactic center with diameters and heights of the order of $H\sim 10$ kpc. We suggest that the periodic star…
We study the advection effect of the Galactic wind on the local cosmic ray spectra. The spectral hardening from a few hundred GV and softening from a few TV are reproduced by a velocity profile with a maximum velocity of $\sim…
The spectral data on the diffuse Galactic gamma-rays, at medium and high latitudes (|b| > 10) and energies of 1-100 GeV, recently published by the Fermi Collaboration are used to produce a novel study on the gamma-ray emissivity in the…