Related papers: On the enhanced cosmic-ray ionization rate in the …
We investigate the diffusion of cosmic rays into molecular cloud complexes. Using the cosmic-ray diffusion formalism of Protheroe, et al. (2008), we examine how cosmic rays diffuse into clouds exhibiting different density structures,…
Molecular clouds act as primary targets for cosmic-ray interactions and are expected to shine in gamma-rays as a by-product of these interactions. Indeed several detected gamma-ray sources both in HE and VHE gamma-rays (HE: 100 MeV < E <…
Understanding the cosmic ray (CR) ionization rate is crucial in order to simulate the dynamics of, and interpret the chemical species observed in molecular clouds. Calculating the CR ionization rate requires both accurate knowledge of the…
Stars and planets form within cold, dark molecular clouds. In these dense regions, where starlight cannot penetrate, cosmic rays (CRs) are the dominant source of ionization -- driving interstellar chemistry(Dalgarno (2006, PNAS, 103,…
Stochastic heating of small grains is often mentioned as a primary cause of large infrared (IR) fluxes from star-forming galaxies, e.g. at 24\mu m. If the mechanism does work at a galaxy-wide scale, it should show up at smaller scales as…
This paper presents the first results of comparison of Planck along with IRAS data with Green Bank Telescope 21-cm observations in 14 fields covering more than 800 square degrees at high Galactic latitude. Galactic dust emission for fields…
Observations of the "Warm Ionized Medium" (or, equivalently, the "Diffuse Ionized Gas") of the local ISM, the Perseus arm in the Milky Way, and also in several other galaxies show strong [NII]6563 (~H-alpha in some cases) and…
In this work, we investigate the contribution of dust scattering to the diffuse H-alpha emission observed in nearby galaxies. As initial conditions for the spatial distribution of HII regions, gas, and dust, we take three Milky Way-like…
Context. Cosmic ray particles that hit interstellar grains in dark molecular cores may induce whole-grain heating. The high temperature of a CR-heated grain allows energy barriers for bulk diffusion and reactions to be overcome.…
Nearby interstellar clouds at high Galactic latitudes are ideal objects in which the interaction of interstellar dust with photons from the well-characterized interstellar radiation field can be studied. Scattering and UV-excited…
Based on a one-zone evolution model of grain size distribution in a galaxy, we calculate the evolution of infrared spectral energy distribution (SED), considering silicate, carbonaceous dust, and polycyclic aromatic hydrocarbons (PAHs). The…
We survey the current situation regarding chemical modelling of the synthesis of molecules in the interstellar medium. The present state of knowledge concerning the rate coefficients and their uncertainties for the major gas-phase processes…
Infrared absorption lines of H3+, including the metastable R(3,3)l line, have been observed toward eight bright infrared sources associated with hot and massive stars located in and between the Galactic Center Cluster and the Quintuplet…
The common approach to compute the cosmic-ray distribution in an starburst galaxy or region is equivalent to assume that at any point within that environment, there is an accelerator inputing cosmic rays at a reduced rate. This rate should…
We present a theoretical investigation of CN and HCN molecule formation in dense interstellar clouds. We study the gas-phase CN and HCN production efficiencies from the outer photon-dominated regions (PDRs) into the opaque cosmic-ray…
The purpose of this work is the characterization of the radial distribution of dust, stars, gas, and star-formation rate (SFR) in a sub-sample of 18 face-on spiral galaxies extracted from the DustPedia sample. This study is performed by…
The rate of ionization by cosmic rays in interstellar gas directly associated with gamma-ray emitting supernova remnants is for the first time calculated to be several orders of magnitude larger than the Galactic average. Analysis of…
We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by $\Gamma_{\rm pe} = 1.2\times10^{-34}$ erg s$^{-1}$ cm$^{-3}$ $({\cal…
Optical CCD spectra are used to determine the Fe abundances at several positions inside seven bright Galactic HII regions. The observed [FeIII] line ratios are compared with the predictions of different sets of collision strengths and…
Interstellar clouds can act as target material for hadronic cosmic rays; gamma rays subsequently produced through inelastic proton-proton collisions and spatially associated with such clouds can provide a key indicator of efficient particle…