Related papers: Gamma-ray lines from cosmic-ray interactions with …
We find significantly different diagnostic emission line ratios for the circumgalactic gas associated with galaxies of stellar masses above and below $10^{10.4}$ M$_\odot$ using SDSS spectroscopy. Specifically, in a sample of 17,393…
The temperatures of interstellar dust grains are analyzed using stochastic simulations, taking into account the grain composition and size and the discreteness of the photon flux. [...] The distribution of grain temperatures is calculated…
We investigate the abundance and properties (especially, grain size) of dust in galaxy halos using available observational data in the literature. There are two major sets of data. One is (i) the reddening curves at redshifts $z\sim 1$ and…
The most important cooling lines of the neutral interstellar medium (ISM) lie in the far-infrared (FIR). We present measurements by the Infrared Space Observatory Long Wavelength Spectrometer of seven lines from neutral and ionized ISM of…
Recent results from the CoGeNT collaboration (as well as the annual modulation reported by DAMA/LIBRA) point toward dark matter with a light (5-10 GeV) mass and a relatively large elastic scattering cross section with nucleons (\sigma ~…
The nature of long-range interactions between dust grains in plasma is discussed. The dust grain interaction potential within a cell model of dusty plasma is introduced. The attractive part of intergrain potential is described by multipole…
Inverse Compton scattering by relativistic electrons produces a major component of the diffuse emission from the Galaxy. The photon fields involved are the cosmic microwave background and the interstellar radiation field from stars and…
X-ray emissions from cometary atmospheres were modeled from first principles using the charge-exchange interaction with solar wind ions as well as coherent scattering of solar X-rays from dust and ice grains. Scattering cross-sections were…
X-ray observations of several active galactic nuclei show prominent iron K-shell fluorescence lines that are sculpted due to special and general relativistic effects. These observations are important because they probe the space-time…
Small angle scatterings of X-rays by interstellar dust particles create halos around x-ray sources. By observing these halos with sufficient angular resolution it is possible to derive information about both the spatial distribution of the…
The recent results obtained by the modern telescopes and spacecrafts allow us for the first time to compare directly the mass, spatial density and size distribution of the dust grains in the regions of their production, processing and…
The attenuation of very high energy gamma rays by pair production on the Galactic interstellar radiation field has long been thought of as negligible. However, a new calculation of the interstellar radiation field consistent with…
The gas-to-dust mass ratios found for interstellar dust within the Solar System, versus values determined astronomically for the cloud around the Solar System, suggest that large and small interstellar grains have separate histories, and…
In the powerful, high redshift radio galaxies, it is believed that the dominant source of ionization for the interstellar gas is the hard radiation field associated with the active nucleus. The photon source is generally external to the…
The interaction of dust grains originating from the local interstellar cloud with the environment inside the heliosphere is investigated. As a consequence of this interaction the spatial distribution of interstellar dust grains changes with…
We report measurements of the [CII] fine structure line at 157.714 micron in 30 normal star-forming galaxies with the Long Wavelength Spectrometer (LWS) on the Infrared Space Observatory (ISO). The ratio of the line to total far-infrared…
The study of the gamma-ray radiation produced by cosmic rays that escape their accelerators is of paramount importance for (at least) two reasons: first, the detection of those gamma-ray photons can serve to identify the sources of cosmic…
A photon of wavelength lambda ~1 micron interacting with a dust grain of radius a_p ~ 1 mm (a "pebble") undergoes scattering in the forward direction, largely within a small characteristic diffraction angle theta_s ~ lambda/a_p ~ 100".…
Recently a series of indications have been put forward suggesting the presence of two gamma-ray lines at 110-130 GeV (centered at 111 and 129 GeV). Signals of these lines have been observed toward the Galactic center, at some galaxy…
Indications for a gamma-ray line(s) signal towards the Galactic center at an energy of about 130 GeV have been recently presented. While dark matter annihilations are a viable candidate for this signal, it is generally expected that such a…