相关论文: High-resolution mapping of interstellar clouds wit…
We discuss the possibility of mapping interstellar clouds at unprecedentedly high spatial resolution by means of near-IR imaging of their scattered light. We calculate the scattering of the interstellar radiation field by a cloud model…
With current near-infrared (NIR) instruments the near-infrared light scattered from interstellar clouds can be mapped over large areas. The surface brightness carries information on the line-of-sight dust column density. Therefore,…
Mapping of near-infrared (NIR) scattered light is a recent method for the study of interstellar clouds, complementing other, more commonly used methods, like dust emission and extinction. Our goal is to study the usability of this method on…
We generalize the technique of Lada et al. (1994) to map dust column density through a molecular cloud (NICE) to an optimized multi-band technique (NICER) that can be applied to any multi-band survey of molecular clouds. We present a first…
We present a method of mapping dust column density in dark clouds by using near-infrared scattered light. Our observations of the Lupus 3 dark cloud indicate that there is a well defined relation between (1) the H-Ks color of an individual…
Several methods exist to convert near-infrared (NIR) stellar observations into extinction maps. We present a new method based on NIR multiband observations. The method uses a discretised version of the distribution of intrinsic stellar…
Sub-millimetre dust emission is often used to derive the column density N of dense interstellar clouds. The observations consist of data at several wavelengths but of variable resolution. We examine two procedures that been proposed for the…
Sub-millimetre dust emission is an important tracer of density N of dense interstellar clouds. One has to combine surface brightness information at different spatial resolutions, and specific methods are needed to derive N at a resolution…
Measuring the mass distribution of infrared dark clouds (IRDCs) over the wide dynamic range of their column densities is a fundamental obstacle in determining the initial conditions of high-mass star formation and star cluster formation. We…
Extinction remains one of the most reliable methods of measuring column density of nearby Galactic interstellar clouds. The current and ongoing near-infrared surveys enable the mapping of extinction over large sky areas. We produce allsky…
With recent Herschel observations, the northern filament of the Corona Australis cloud has now been mapped in a number of bands from 1.2um to 870um. The data set provides a good starting point for the study of the cloud over several orders…
We consider from a general point of view the problem of determining the extinction in dense molecular clouds. We use a rigorous statistical approach to characterize the properties of the most widely used optical and infrared techniques,…
(Abridged) We use 8 micron Spitzer GLIMPSE images to make extinction maps of 10 IRDCs, selected to be relatively nearby and massive. The extinction mapping technique requires modeling the IR background intensity behind the cloud, which is…
We study a northern part of the Corona Australis molecular cloud that consists of a filament and a dense sub-millimetre core inside the filament. Our aim is to measure dust temperature and sub-mm emissivity within the region. We also look…
We study the near-infrared (NIR) scattering in LDN 1642, its correlation with the cloud structure, and the ability of dust models to simultaneously explain sub-millimetre emission, NIR extinction, and NIR scattering. We use observations…
Context: Infrared Dark Clouds (IRDCs) harbor progenitors of high-mass stars. Little is known of the parental molecular clouds of the IRDCs. Aims: We demonstrate the feasibility of the near-infrared (NIR) dust extinction mapping in tracing…
Progress in understanding star formation requires detailed observational constraints on the initial conditions, i.e. dense clumps and cores in giant molecular clouds that are on the verge of gravitational instability. Such structures have…
We are studying the column density distribution of all nearby giant molecular clouds. As part of this project we generated several all sky extinction maps. They are calculated using the median near infrared colour excess technique applied…
[Abridged] The giant molecular clouds (GMCs) of external galaxies can be mapped with sub-arcsecond resolution using multiband observations in the near-infrared. However, the interpretation of the observed features, and their transformation…
Light scattering at near-infrared wavelengths has been used to study the optical properties of the interstellar dust grains, but these studies are limited by the assumptions on the strength of the radiation field. On the other hand, thermal…