Related papers: Gas absorption and dust extinction towards the Ori…
We present a comparison of the gas and dust properties of the dense interstellar matter in six nearby star-forming regions (d<500 pc): rho Oph, Cha I, R CrA, IC 348, NGC 1333, and Orion. We measure from Chandra and XMM-Newton observations…
We investigate the relation between the optical extinction ($A_V$) and the hydrogen column density ($N_H$) determined from X-ray observations of a large sample of Galactic sightlines toward 35 supernova remnants, 6 planetary nebulae, and 70…
We present observational evidences that dust in the circumnuclear region of AGNs has different properties than in the Galactic diffuse interstellar medium. By comparing the reddening of optical and infrared broad lines and the X-ray…
We re-examine the recombination/collisional emission line (RL/CEL) nebular abundance discrepancy problem in the light of recent high-quality abundance determinations in young stars in the Orion star-forming region. We re-evaluate the CEL…
We have investigated the shape of the extinction curve in the infrared up to ~25 {\mu}m for the Orion A star-forming complex. The basis of this work is near-infrared data acquired with VISTA, in combination with Pan-STARRS and mid-infrared…
A linear relation between the hydrogen column density (N_H) and optical extinction (A_V) in the Galaxy has long been observed. A number of studies found differing results in the slope of this relation. Here, we utilize the data on 22…
In the past few years, the extinction law has been measured in the infrared wavelengths for various molecular clouds and different laws have been obtained. In this paper we seek variations of the extinction law within the Trifid nebula…
Observations of interstellar dust are often used as a proxy for total gas column density $N_\mathrm{H}$. By comparing $\textit{Planck}$ thermal dust data (Release 1.2) and new dust reddening maps from Pan-STARRS 1 and 2MASS (Green et al.…
We have studied optical properties of interstellar dust around the Orion A molecular cloud to investigate the size distribution and the composition of dust grains. Orion A is one of the most studied molecular clouds in the solar vicinity…
The optical classification of a Seyfert galaxy and whether it is considered X-ray absorbed are often used interchangeably. But there are many borderline cases and also numerous examples where the optical and X-ray classifications appear to…
In this paper we present the results from the analysis of a sample of 28 gamma-ray burst (GRB) afterglow spectral energy distributions, spanning the X-ray through to near-infrared wavelengths. This is the largest sample of GRB afterglow…
We propose a classification scheme for the circumnuclear medium of AGNs based on their location in the A_V - N_H plane (related to dust absorption and gas absorption, respectively). We present evidence that the A_V/N_H ratio is often lower…
The gas-to-dust ratio of reddened stars in the Milky Way (MW), the Magellanic Clouds, and in general is usually expressed as a linear relation between the hydrogen column density, N(H), and the reddening, E(B-V), or extinction in the V band…
(abridged) We report a study of the relation between dust and gas over a 100deg^2 area in the Taurus molecular cloud. We compare the H2 column density derived from dust extinction with the CO column density derived from the 12CO and 13CO J=…
We present a comprehensive study of interstellar X-ray extinction using the extensive Chandra supernova remnant archive and use our results to refine the empirical relation between the hydrogen column density and optical extinction. In our…
We report optical extinction properties of dust for a sample of 26 early-type galaxies based on the analysis of their multicolour CCD observations. The wavelength dependence of dust extinction for these galaxies is determined and the…
Dust plays a central role in the unification theory of active galactic nuclei (AGNs). However, little is known about the nature (e.g., size, composition) of the dust which forms a torus around the AGN. In this Letter we report a systematic…
Young stars are surrounded by copious amounts of circumstellar material. Its composition, in particular its gas-to-dust ratio, is an important parameter. However, measuring this ratio is challenging, because gas mass estimates are often…
We present values for angular diameter, flux and extinction for 70 Galactic planetary nebulae observed using narrow band filters. Angular diameters are derived using constant emissivity shell and photoionization line emission models. The…
The state-of-the-art geometry models of stars/dust suggest that dust attenuation toward nebular regions ($A_{V,gas}$) is always larger than that of stellar regions ($A_{V,star}$). Utilizing the newly released integral field spectroscopic…