Related papers: Is Dust Cloud around $\lambda$ Orionis a Ring or a…
Using NICMOS on HST, we have performed imaging polarimetry of proto-planetary nebulae. Our objective is to study the structure of optically thin circumstellar shells of post-asymptotic giant branch stars by separating dust-scattered,…
Infrared emission from the dust shell around IRC+10216 is analysed in detail, employing a self-consistent model for radiatively driven winds around late-type stars that couples the equations of motion and radiative transfer in the dust. The…
This paper examines the density and velocity structure of envelopes around young stellar objects through submillimeter continuum imaging of four objects in Taurus and previously obtained molecular-line data. Observations carried out with…
We present a high-resolution $1.5"$ observational study towards two massive dust-and-gas cores, ORI8nw\_2 and ORI2\_6 in Orion Molecular Cloud using the Combined Array for Research in Millimeter-wave Astronomy (CARMA). In both regions the…
We analyze the spatial distribution of dusty young stellar objects (YSOs) identified in the Spitzer Survey of the Orion Molecular clouds, augmenting these data with Chandra X-ray observations to correct for incompleteness in dense clustered…
In this contribution, we test our previously published one-dimensional PDR model for deriving total hydrogen volume densities from HI column density measurements in extragalactic regions by applying it to the Taurus molecular cloud, where…
Sticky particle calculations indicate that a coherent structure, a dispersion ring, forms when a cloud on a low angular momentum orbit passes close to the dynamical center of an isothermal sphere containing a central point mass. The cloud…
Thanks to deep UV observations with GALEX and Swift, diffuse UV haloes have recently been discovered around galaxies. Based on UV-optical colours, it has been advocated that the UV haloes around spiral galaxies are due to UV radiation…
Recent observations with the Submillimeter Wave Astronomy Satellite indicate abundances of gaseous H2O and O2 in dense molecular clouds which are significantly lower than found in standard homogeneous chemistry models. We present here…
Mid-infrared arcs of dust emission are often seen near ionizing stars within HII regions. A possible explanations for these arcs is that they could show the outer edges of asymmetric stellar wind bubbles. We use two-dimensional,…
The structure of dark matter halos as predicted from cosmological models is discussed and compared with observed rotation curves of dark matter-dominated dwarf galaxies. The theoretical models predict that dark matter halos represent a…
We present the high angular resolution and high sensitivity images of the "Circum-Nuclear Disk (CND)" and its surrounding region of Milky Way Galaxy in the CS J=2-1, SiO v=0 J=2-1, H^13CO^+ J=1-0, C^34S J=2-1, and CH_3OH J_{K_a,…
(abridged) This review is based on an extensive work done in collaboration with N. Gorkavyi, J. Mather, and T. Taidakova, which aimed at the physical modelling of the interplanetary dust (IPD) cloud in the Solar system, i.e., establishing a…
Optical stellar polarimetry in the Perseus molecular cloud direction is known to show a fully mixed bi-modal distribution of position angles across the cloud (Goodman et al. 1990). We study the Gaia trigonometric distances to each of these…
We investigate the emission of active galactic nuclei (AGN) dusty tori in the infrared domain. Following theoretical predictions coming from hydrodynamical simulations, we model the dusty torus as a 3D two-phase medium with high-density…
The Lambda Orionis Star Forming Region is dominated by the O8 III star lambda^1 Ori. Among other structures, it includes a CO and a dust ring whose diameter is about nine deg, the S264 HII region, a large number of IRAS sources, the Barnard…
We present two wide-field (5'x5'), diffraction limited, broad-band 10 and 20 micron images of the Orion Nebula, plus six 7-13 micron narrow-band images of BN/KL taken at the 3.8m UKIRT telescope. The wide-field images are mosaics of 35"x35"…
We present Orion A giant molecular cloud core catalogs, which are based on 1.1 mm map with an angular resolution of 36 arcsec (sim 0.07 pc) and C18O (1-0) data with an angular resolution of 26.4 arcsec (sim 0.05 pc). We have cataloged 619…
We study the intrinsic shape and alignment of isodensities of galaxy cluster halos extracted from the MultiDark MDR1 cosmological simulation. We find that the simulated halos, are extremely prolate on small scales, and increasingly…
Context: State of the art quantitative spectroscopy of OB-stars compares synthetic spectra (calculated by means of 1D, spherically symmetric computer codes) with observations. Certain stellar atmospheres, however, show strong deviations…