Related papers: X-Ray Absorption and Scattering by Interstellar Gr…
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".…
Models invoking large populations of obscured AGN are known to provide good fits to the spectrum of the X-ray background and the observed soft and hard X-ray number counts. An important consequence of these models is that significant…
The stochastic nature of star formation and photon propagation in high-redshift galaxies can result in sizable galaxy-to-galaxy scatter in their properties. Ignoring this scatter by assuming mean quantities can bias estimates of their…
We predict a thin (scale height $\sim$ 80 pc) diffuse component of the Galactic Ridge X-ray emission (GRXE) arising from the scattering of the radiation of bright X-ray binaries (XBs) by the interstellar medium (ISM). The morphology of this…
In 1992 the Far-Ultraviolet Space Telescope (FAUST) provided measurements of the ultraviolet (140-180nm) diffuse sky background at high, medium, and low Galactic latitudes. A significant fraction of the detected radiation was found to be of…
We describe the use of partially overlapping galaxies to provide direct measurements of the effective absorption in galaxy disks, independent of assumptions about internal disk structure. The non-overlapping parts of the galaxies and…
The origin of excess of X-ray column density with respect to optical extinction in Gamma-ray bursts (GRBs) is still a puzzle. A proposed explanation of the excess is the photoelectric absorption due to the intervening clouds along a GRB's…
We have developed a new model that uses a cellular approach to calculate radiative transfer of starlight through dusty media. The model is designed to be user friendly enough to be distributed as a tool for use by the general astronomical…
Nanometer- and micrometer-sized solid particles play an important role in the evolutionary cycle of stars and interstellar matter. The optical properties of cosmic grains determine the interaction of the radiation field with the solids,…
We investigate shattering and coagulation of dust grains in turbulent interstellar medium (ISM). The typical velocity of dust grain as a function of grain size has been calculated for various ISM phases based on a theory of grain dynamics…
In high-redshift ($z>5$) quasars, a large amount of dust ($\textstyle\sim 10^{8} \mathrm{M}_{\sun}$) has been observed. In order to explain the large dust content, we focus on a possibility that grain growth by the accretion of heavy…
X-ray surveys have revealed a new class of active galactic nuclei (AGN) with a very low observed fraction of scattered soft X-rays, f_scat < 0.5%. Based on X-ray modeling these "X-ray new-type", or low observed X-ray scattering…
Grazing incidence X-ray scattering experiments are designed to achieve strong scattering signals from materials, such as molecular monolayers, island films, or thin films that are localized to the surfaces of flat substrates. Optimal…
In this work we investigate the effects of ion accretion and size-dependent dust temperatures on the abundances of both gas-phase and grain-surface species. While past work has assumed a constant areal density for icy species, we show that…
X-ray interferometry is an emerging imaging modality with a wide variety of potential clinical applications, including lung and breast imaging, as well as in non-destructive testing, such as additive manufacturing and porosimetry. A grating…
We present evolutionary calculations for the size and aromatization degree distributions of interstellar dust grains, driven by their destruction by radiation, collisions with gas particles, and shattering due to grain-grain collisions.…
We provide simple polynomial fits to the X-ray photoelectric cross-sections (0.03 < E < 10keV) for mixtures of gas and dust found in protoplanetary disks. Using the solar elemental abundances of Asplund et al. (2009) we treat the gas and…
We consider the lifecycle of dust introduced into the hot interstellar medium in isolated elliptical galaxies. Dust grains are ejected into galactic-scale cooling flows in large ellipticals by normal mass loss from evolving red giants.…
We explore whether assumptions about dust grain shape affect resulting estimates of the composition and grain size distribution of the AU Microscopii (AU Mic) debris disk from scattered light data collected by Lomax et al. (2018). The near…
Using CCD detectors onboard the forthcoming X-ray observatories Chandra and XMM, it is possible to devise a measurement of the absolute density of heavy elements in the hypothetical warm gas filling intercluster space. This gas may be the…