Related papers: New Interstellar Dust Models Consistent with Extin…
We present a new technique for determining the *quantity and composition* of dust in astrophysical environments using <6keV X-rays. We argue that high resolution X-ray spectra as enabled by the Chandra and XMM-Newton gratings should be…
We explore the possibility that the steepening observed shortward of 1000A in the energy distribution of quasars may result from absorption by dust, being either intrinsic to the quasar environment or intergalactic. We find that a dust…
[Abridged] We present a new approach to investigate the content and spatial distribution of dust in structurally unresolved star-forming galaxies from the observed dependence of integrated spectral properties on galaxy inclination. We…
We model the interstellar dust content of the reionization era with a suite of cosmological, fluid-dynamical simulations of galaxies with stellar masses ranging from $\sim 10^5 - 10^9 M_{\odot}$ in the first $1.2$ billion years of the…
We study the absorption and scattering of X-ray radiation by interstellar dust particles, which allows us to access the physical and chemical properties of dust. The interstellar dust composition is not well understood, especially on the…
We present mid-infrared to optical properties of 22 representative irregular galaxies: 18 Im, 3 BCDs, and one Sm. The mid-IR is based on images from the Spitzer Space Telescope archives. The 3.6 and 4.5 micron bands and the UBVJHK images…
We investigate the properties of dust and dust-to-gas ratios in different starburst regions of luminous infrared galaxies (LIGs). We refer to the sample of seven LIGs recently observed in the mid-infrared by Soifer et al. (2001) using the…
The mid-infrared is an optimal window to trace stellar mass in nearby galaxies and the 3.6$\mu m$ IRAC band has been exploited to this effect, but such mass estimates can be biased by dust emission. We present our pipeline to reveal the old…
We present the results of millimeter and centimeter continuum observations, made with the IRAM 30m telescope and the VLA, toward a sample of 11 luminous IRAS sources classified as high-mass protostellar object candidates. We find 1.2 mm…
Seven Class 0 sources mapped with SCUBA at 850 and 450 micron are modeled using a one dimensional radiative transfer code. The modeling takes into account heating from an internal protostar, heating from the ISRF, realistic beam effects,…
It is well known that the extinction properties along lines of sight to Type Ia supernovae are described by steep extinction curves with unusually low total-to-selective extinction ratios of Rv = 1.0-2.0. In order to reveal the properties…
The chemical abundance patterns of near-pristine objects provide important constraints on the properties of the first generations of stars in the Universe. We present the chemical abundances of five very metal-poor ([M/H]<-2.5) sub damped…
We have observed a small sample of hot post-AGB stars with the InfraRed Array Camera (IRAC) and the InfraRed Spectrograph (IRS) on-board the Spitzer Space Telescope. The stars were selected from the literature on the basis of their…
We have constructed three-dimensional models for the equilibrium abundance of molecular hydrogen within diffuse interstellar clouds of arbitrary geometry that are illuminated by ultraviolet radiation. The position-dependent photo-…
We present models of photometric evolution of galaxies in which the effects of a dusty interstellar medium have been included with particular care. A chemical evolution code follows the star formation rate, the gas fraction and the…
The structure of inner region of protoplanetary disks around young pre-main-sequence stars is still poorly understood. This part of the disk is shaped by various forces that influence dust and gas dynamics, and by dust sublimation, which…
Infrared spectra of a number of evolved O-rich stars have been obtained with the Short- and Long- Wavelength spectrometers on board the Infrared Space Observatory. The very broad wavelength coverage (2.4-197 micron) obtained by combining…
Photodissociation regions (PDRs) are parts of the ISM consisting of predominantly neutral gas, located at the interface between H II regions and molecular clouds. The physical conditions within these regions show variations on very short…
We use published ROSAT observations of the X-ray Nova V1974 Cygni 1992 to test a model for interstellar dust, consisting of a mixture of carbonaceous grains and silicate grains. The time-dependent X-ray emission from the nova is modelled,…
Scattering and absorption of light by a homogeneous distribution of intergalactic large dust grains has been proposed as an alternative, non-cosmological explanation for the faintness of Type Ia supernovae at $z\s im 0.5$. We investigate…