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Related papers: Temperature fluctuations of interstellar dust grai…

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We argue that impact velocities between dust grains with sizes less than $\sim 0.1$ $\mu m$ in molecular cloud cores are dominated by drift arising from ambipolar diffusion. This effect is due to the size dependence of the dust coupling to…

Astrophysics of Galaxies · Physics 2020-09-30 Kedron Silsbee , Alexei Ivlev , Paola Caselli , Olli Sipila , Bo Zhao

The evolution of the dust grain size distribution has been studied in recent years with great detail in cosmological hydrodynamical simulations taking into account all the channels under which dust evolves in the interstellar medium. We…

Interstellar dust is an essential component of the interstellar medium (ISM) and plays critical roles in astrophysics. Achieving an accurate model of interstellar dust is therefore of great importance. Interstellar dust models are usually…

Astrophysics of Galaxies · Physics 2019-05-01 Thiem Hoang

Cosmic-ray-induced whole-grain heating induces evaporation and other processes that affect the chemistry of interstellar clouds. With recent data on grain heating frequencies as an input for a modified rate-equation astrochemical model,…

Astrophysics of Galaxies · Physics 2019-04-26 Juris Kalvans , Juris Roberts Kalnin

Ice is ubiquitous in the interstellar medium. We model the formation of the main constituents of interstellar ices, including H2O, CO2 , CO, and CH3 OH. We strive to understand what physical or chemical parameters influence the final…

Astrophysics of Galaxies · Physics 2023-07-26 A. Clément , A. Taillard , V. Wakelam , P. Gratier , J. -C. Loison , E. Dartois , F. Dulieu , J. A. Noble , M. Chabot

We review the properties of dust in protoplanetary disks around optically visible pre-main sequence stars obtained with a variety of observational techniques, from measurements of scattered light at visual and infrared wavelengths to…

Astrophysics · Physics 2007-05-23 A. Natta , L. Testi , N. Calvet , Th. Henning , R. Waters , D. Wilner

By radiation transfer models with a realistic power spectra of the projected density distributions, we show that the optical properties of grains are poorly constrained by observations of reflection nebulae. The ISM is known to be…

Astrophysics · Physics 2009-11-07 John S. Mathis , Barbara A. Whitney , Kenneth Wood

Theoretical studies have revealed that dust grains are usually moving fast through the turbulent interstellar gas, which could have significant effects upon interstellar chemistry by modifying grain accretion. This effect is investigated in…

Astrophysics of Galaxies · Physics 2015-12-09 J. X. Ge , J. H. He , H. R. Yan

We have analyzed the effects of photoelectric heating by dust grains in photoionization models of planetary nebulae. We have shown that this process is particularly important if planetary nebulae contain a population of small grains. The…

Astrophysics · Physics 2009-11-07 Grazyna Stasinska , Ryszard Szczerba

We develop a self-consistent model for the equilibrium gas temperature and size-dependent dust temperature in cold, dense pre-stellar cores, assuming an arbitrary power-law size distribution of dust grains. Compact analytical expressions…

Astrophysics of Galaxies · Physics 2019-11-06 Alexei V. Ivlev , Kedron Silsbee , Olli Sipilä , Paola Caselli

We investigate the claim that the ratio {\beta} of radiation pressure force to gravitational force on a dust grain in our solar system can substantially exceed unity for some grain sizes, provided that grain porosity is high enough. For…

Earth and Planetary Astrophysics · Physics 2016-03-09 Kedron Silsbee , Bruce T. Draine

The 500 central pc of the Galaxy (hereafter GC) exhibit a widespread gas component with a kinetic temperature of 100-200 K. The bulk of this gas is not associated to the well-known thermal radio continuum or far infrared sources like Sgr A…

Astrophysics · Physics 2009-11-10 N. J Rodriguez-Fernandez , J. Martin-Pintado , A. Fuente , T. L. Wilson

We develop a model of dust evolution in a multiphase, inhomogeneous ISM including dust growth and destruction processes. The physical conditions for grain evolution are taken from hydrodynamical simulations of giant molecular clouds in a…

Astrophysics of Galaxies · Physics 2016-11-09 Svitlana Zhukovska , Clare Dobbs , Edward B. Jenkins , Ralf Klessen

Grains exposed to anisotropic radiation fields are subjected to forces due to the asymmetric photon-stimulated ejection of particles. These forces act in addition to the ``radiation pressure'' due to absorption and scattering. Here we model…

Astrophysics · Physics 2009-10-31 Joseph C. Weingartner , B. T. Draine

Interstellar dust grains can be spun up by radiative torques, and the resulting centrifugal force may be strong enough to disrupt large dust grains. We examine the effect of this rotational disruption on the evolution of grain size…

Astrophysics of Galaxies · Physics 2020-04-08 Hiroyuki Hirashita , Thiem Hoang

Thermal ionization is a critical process at temperatures T > 10 3 K, particularly during star formation. An increase in ionization leads to a decrease in nonideal magnetohydrodynamics (MHD) resistivities, which has a significant impact on…

Solar and Stellar Astrophysics · Physics 2022-10-05 Pierre Marchand , Vincent Guillet , Ugo Lebreuilly , Mordecai-Mark Mac Low

Context. Grains in circumstellar disks are believed to grow by mutual collisions and subsequent sticking due to surface forces. Results of many fields of research involving circumstellar disks, such as radiative transfer calculations, disk…

Earth and Planetary Astrophysics · Physics 2010-09-20 T. Birnstiel , C. W. Ormel , C. P. Dullemond

Context: Fast surface conversion between ortho- and para-H2 has been observed in laboratory studies, and this mechanism has been proposed to play a role in the control of the ortho-para ratio in the interstellar medium. Observations of…

Astrophysics of Galaxies · Physics 2016-03-16 Emeric Bron , Franck Le Petit , Jacques Le Bourlot

Physical conditions of the interstellar medium in galaxies are closely linked to the ambient radiation field and the heating of dust grains. In order to characterize dust properties in galaxies over a wide range of physical conditions, we…

Cold dust grains emission in the FIR/submm is usually expressed as a modified black body law in which the dust mass absorption coefficient (MAC), is described with a temperature- and wavelength-independent emissivity spectral index, beta.…

Astrophysics of Galaxies · Physics 2015-05-30 A. Coupeaud , K. Demyk , C. Meny , C. Nayral , F. Delpech , H. Leroux , C. Depecker , G. Creff , J. B. Brubach , P. Roy