Optical properties and dust temperatures in clumpy diffuse medium
arXiv:2005.10601 · doi:10.1093/mnras/staa1460
Abstract
In this study, we explore the impact of inhomogeneities in the spatial distribution of interstellar dust on spatial scales of au caused by ion shadowing forces on the optical properties of diffuse interstellar medium (ISM) as well as on the dust temperature. We show that recently proposed possibility that interstellar dust grains in the diffuse ISM are grouped in spherical cloudlets (clumps) may significantly affect the observed optical properties of the diffuse ISM in comparison to that calculated under the commonly accepted assumption on the uniform dust/gas mixture if the size of clumps au. We found that opacity of an arbitrary region of diffuse ISM quickly decreases with growth of dusty clumps. We also studied the dependence of opacity and dust temperature inside the dusty clumps on their size. We show that the clumps larger than 0.1 au are opaque for far ultraviolet radiation. Dust temperature exhibit a gradient inside a clump, decreasing from the edge to the center by several degrees for a clump of a size of 0.1 au and larger. We argue that dust temperatures and high opacity within clumps larger than 0.1 au may facilitate somewhat more efficient synthesis of molecules on surfaces of interstellar grains in the diffuse ISM than it was anticipated previously. On the other hand, the presence of clumps with sizes below 0.1 au makes small or negligible influence on the optical properties of the diffuse ISM in comparison to the case with uniform dust/gas mixture.
arXiv comment13 pages, 7 figures, accepted to MNRAS
References in corpus (28)
- Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
- AGN Dusty Tori: I. Handling of Clumpy Media
- A KInetic Database for Astrochemistry (KIDA)
- Dust Emission from Active Galactic Nuclei
- Scattering by Interstellar Dust Grains. II. X-Rays
- Multiple Scattering in Clumpy Media. II. Galactic Environments
- Reactive Desorption and Radiative Association as Possible Drivers of Complex Molecule Formation in the Cold Interstellar Medium
- HYPERION: An open-source parallelized three-dimensional dust continuum radiative transfer code
- Comparative study of CH+ and SH+ absorption lines observed towards distant star-forming regions
- Rotational Disruption of Dust Grains by Radiative Torques in Strong Radiation Fields
- Chemical probes of turbulence in the diffuse medium: the TDR model
- Analytical Approximations for Calculating the Escape and Absorption of Radiation in Clumpy Dusty Environments
- A dynamical constraint on interstellar dust models from radiative torque disruption
- Monte Carlo simulations of H2 formation on stochastically heated grains
- A clumpy-cloud PDR model of the global far-infrared line emission of the Milky Way
- Atomic and Ionized Microstructures in the Diffuse Interstellar Medium
- Diffuse Molecular Cloud Densities from UV Measurements of CO Absorption
- The Interstellar Oxygen Crisis, or Where Have All the Oxygen Atoms Gone?
- Complex organic molecules in diffuse clouds along the line of sight to Sgr B2
- Free-Free Spectral Energy Distributions of Hierarchically Clumped HII Regions
- Molecular ion abundances in the diffuse ISM : CF+, HCO+, HOC+, and C3H+
- Modeling the Infrared Interstellar Extinction
- Chemical complexity in local diffuse and translucent clouds: ubiquitous l-C3H and CH3CN, a detection of HC3N and an upper limit on the abundance of CH2CN
- Extinction and dust properties in a clumpy medium
- Compact dusty clouds in cosmic environment
- Variations between Dust and Gas in the Diffuse Interstellar Medium. 3. Changes in Dust Properties
- Compact dusty clouds and efficient H formation in diffuse ISM
- Continuum and Spectral Line Radiation from a Random Clumpy Medium