相关论文: Ambipolar Diffusion and Far-Infrared Polarization …

Dust is observed in the polar regions of nearby AGN and it is known to contribute substantially to their mid-IR emission and to the obscuration of their UV to optical emission. We selected a sample of 1275 BLAGN in the XMM-XXL field, with…

Polarized microwave emission from dust is an important foreground that may contaminate polarized CMB studies unless carefully accounted for. We discuss potential difficulties associated with this foreground, namely, the existence of…

Transitional protostellar disks have inner cavities heavily depleted in dust and gas, yet most show signs of ongoing accretion, often at rates comparable to full disks. We show that recent constraints on the gas surface density in a few…

Star formation proceeds via the collapse of a molecular cloud core over multiple dynamical timescales. Turbulence within cores results in a spatially non-uniform angular momentum of the cloud, causing a stochastic variation in orientation…

Aligned non-spherical dust particles polarize starlight passing through the dust cloud. They also emit polarized far infrared and sub-mm radiation. Substantial progress in understanding of grain alignment theory makes the interpretation of…

We present a phenomological model of the Cosmic Spectral Energy Distribution (CSED) and the integrated galactic light (IGL) over all cosmic time. This model, based on an earlier model by Driver et al. (2013), attributes the cosmic star…

Nearly all young stars are initially surrounded by `protoplanetary' discs of gas and dust, and in the case of single stars at least 30\% of these discs go on to form planets. The process of protoplanetary disc formation can result in…

Molecular clouds in the Galactic center (GC) reprocess radiation from past outbursts of nearby high-energy sources, generating a bright Fe K-alpha fluorescence at 6.4 keV. The closest clouds to the GC are only $\simeq 1.5$ pc from Sgr A*,…

We investigate the dynamical condensation process in a magnetized thermally bistable medium. We perform one-dimensional two fluid numerical simulations that describe the neutral and ionized components in the interstellar medium with purely…

This paper re-examines the problem of ambipolar diffusion as a mechanism for the production and runaway evolution of centrally condensed molecular cloud cores, a process that has been termed the gravomagneto catastrophe. Our calculation…

Sharp fronts observed by Chandra satellite between dense cool cluster cores moving with near-sonic velocity through the hotter intergalactic gas, require strong suppression of thermal conductivity across the boundary. This may be due to…

Radiative transfer models were developed to understand the optical polarizations in edge-on galaxies, which are observed to occur even outside the geometrically thin dust disk, with a scale height of ~ 0.2 kpc. In order to reproduce the…

Infrared observations of active galactic nucleus (AGN) reveal emission from the putative dusty circumnuclear 'torus' invoked by AGN unification, that is heated up by radiation from the central accreting black hole (BH). The strong 9.7 and…

Recent Planck results have shown that radiation from the cosmic microwave background passes through foregrounds in which aligned dust grains produce polarized dust emission, even in regions of the sky with the lowest level of dust emission.…

We report new dust polarization results of a nearly edge-on disk in the HH 212 protostellar system, obtained with ALMA at ~ 0.035" (14 au) resolution in continuum at lambda ~ 878 um. Dust polarization is detected within ~ 44 au of the…

It is believed that magnetic field lines are twisted and bend by turbulent motions in the Galaxy. Therefore, both Galactic synchrotron emission and thermal emission from dust reflects statistics of Galactic turbulence. Our simple model of…

We have shown that the thermal emission of the amorphous dust composed of amorphous silicate dust (a-Si) and amorphous carbon dust (a-C) provides excellent fit both to the observed intensity and the polarization spectra of molecular clouds.…

The obscuring structure surrounding active galactic nuclei (AGN) can be explained as a dust and gas flow cycle that fundamentally connects the AGN with their host galaxies. This structure is believed to be associated with dusty winds driven…

I explore models of the dust-scattered component of the Cosmic Ultraviolet Background (CUVB) at the North Galactic Pole (NGP) in order to develop a framework for calculating the dust-scattered light as a function of the optical depths. As…

Polarized emission from aligned dust is a crucial tool for studies of magnetism in the ISM and a troublesome contaminant for studies of CMB polarization. In each case, an understanding of the significance of the polarization signal requires…