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Related papers: Is the dust-to-gas ratio constant in molecular clo…

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We study the behavior of large dust grains in turbulent molecular clouds (MCs). In primarily neutral regions, dust grains move as aerodynamic particles, not necessarily with the gas. We therefore directly simulate, for the first time, the…

Astrophysics of Galaxies · Physics 2016-11-09 Philip F. Hopkins , Hyunseok Lee

Using the Planck far-infrared and Arecibo GALFA 21-cm line surveys, we identified a set of isolated interstellar clouds (approximately degree-sized on the sky and comprising 100 solar masses) and assessed the ratio of gas mass to dust mass.…

Astrophysics of Galaxies · Physics 2015-10-07 William T. Reach , Carl Heiles , Jean-Philippe Bernard

We present high resolution ($1024^3$) simulations of super-/hyper-sonic isothermal hydrodynamic turbulence inside an interstellar molecular cloud (resolving scales of typically 20 -- 100 AU), including a multi-disperse population of dust…

Astrophysics of Galaxies · Physics 2018-12-19 Lars Mattsson , Akshay Bhatnagar , Fred A. Gent , Beatriz Villarroel

The aim of this study is to examine dust dynamics on a large scale and investigate the coupling of dust with gas fluid in the star formation process. We propose a method for calculating the dust trajectory in a gravitationally collapsing…

Astrophysics of Galaxies · Physics 2022-08-17 Shunta Koga , Yoshihiro Kawasaki , Masahiro N. Machida

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

We show that the growth rate of dust grains in cold molecular clouds is enhanced by the high degree of compressibility of a turbulent, dilute gas. By means of high resolution (10243) numerical simulations, we confirm the theory that the…

Astrophysics of Galaxies · Physics 2020-11-18 Xiang-Yu Li , Lars Mattsson

It has recently been shown that turbulence in the interstellar medium (ISM) can significantly accelerate the growth of dust grains by accretion of molecules, but the turbulent gas-density distribution also plays a crucial role in shaping…

Astrophysics of Galaxies · Physics 2020-10-09 Lars Mattsson

We study the dynamics of large, charged dust grains in turbulent giant molecular clouds (GMCs). Massive dust grains behave as aerodynamic particles in primarily neutral dense gas, and thus are able to produce dramatic small-scale…

Astrophysics of Galaxies · Physics 2017-07-11 Hyunseok Lee , Philip F. Hopkins , Jonathan Squire

Dust is the usual minor component of the interstellar medium. Its dynamic role in the contraction of the diffuse gas into molecular clouds is commonly assumed to be negligible because of the small mass fraction, $f \simeq 0.01$. However, as…

Astrophysics of Galaxies · Physics 2020-11-11 V. V. Zhuravlev

The dynamics of dust and gas can be quite different from each other when the dust is poorly coupled to the gas. In protoplanetary discs, it is well known that this decoupling of the dust and gas can lead to diverse spatial structures and…

Astrophysics of Galaxies · Physics 2016-11-10 Matthew R. Bate , Pablo Loren-Aguilar

Molecular clouds are regions of dense gas and dust in space where new stars and planets are born. There is a strong correlation between the distribution of dust and molecular gas in molecular clouds. The present work focuses on the…

Astrophysics of Galaxies · Physics 2024-10-28 Rui-Zhi Li , Bing-Qiu Chen , Guang-Xing Li , Bo-Ting Wang , Hao-Ming Ren , Qi-Ning Guo

Dust grain dynamics in molecular clouds is regulated by its interplay with supersonic turbulent gas motions. The conditions under which dust grains decouple from the dynamics of gas remain poorly constrained. We first aim to investigate the…

In dense molecular clouds collisions between dust grains alter the ISM-dust size distribution. We study this process by inserting the results from detailed numerical simulations of two colliding dust aggregates into a coagulation model that…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. W. Ormel , D. Paszun , C. Dominik , A. G. G. M. Tielens

(Abridged) Context: The assumption of a gas-to-dust mass ratio (\gamma) is a common approach to estimate the basic properties of molecular clouds, such as total mass and column density of molecular hydrogen, from (sub)mm continuum…

Astrophysics of Galaxies · Physics 2017-11-01 A. Giannetti , S. Leurini , C. Koenig , J. S. Urquhart , T. Pillai , J. Brand , J. Kauffmann , F. Wyrowski , K. M. Menten

Maps of estimated dust column density in molecular clouds are usually assumed to reliably trace the total gas column density structure. In this work we present results showing a clear discrepancy between the dust and the gas distribution in…

Dust grains in neutral gas behave as aerodynamic particles, so they can develop large density fluctuations independent of gas density fluctuations. Specifically, gas turbulence can drive order-of-magnitude 'resonant' fluctuations in the…

Astrophysics of Galaxies · Physics 2015-12-15 Philip F. Hopkins

We carried out 12CO(J=2-1) observations toward three star-forming galaxies on the main sequence at z~1.4 with the Nobeyama 45m radio telescope. These galaxies are detected with Spitzer/MIPS in 24 um, Herschel/SPIRE in 250 um and 350 um, and…

Astrophysics of Galaxies · Physics 2015-06-22 Akifumi Seko , Kouji Ohta , Bunyo Hatsukade , Kiyoto Yabe , Tomoe Takeuchi , Daisuke Iono

The gas-to-dust mass ratios found for interstellar dust within the Solar System, versus values determined astronomically for the cloud around the Solar System, suggest that large and small interstellar grains have separate histories, and…

We investigate the gas-grain relative drift velocity distributions of charged astrophysical dust grains in MHD turbulence. We do this using a range of MHD-PIC simulations spanning different plasma-$\beta$, sonic/Alfv\'en Mach number, and…

Astrophysics of Galaxies · Physics 2025-08-28 Eric R. Moseley , Romain Teyssier
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