Clustering and dynamic decoupling of dust grains in turbulent molecular clouds

Research output: Contribution to journalArticleScientificpeer-review

Standard

Clustering and dynamic decoupling of dust grains in turbulent molecular clouds. / Mattsson, Lars; Bhatnagar, Akshay; Gent, Frederick; Villarroel, Beatriz.

In: Monthly Notices of the Royal Astronomical Society, Vol. 483, No. 4, 11.03.2019, p. 5623–5641.

Research output: Contribution to journalArticleScientificpeer-review

Harvard

APA

Vancouver

Author

Mattsson, Lars ; Bhatnagar, Akshay ; Gent, Frederick ; Villarroel, Beatriz. / Clustering and dynamic decoupling of dust grains in turbulent molecular clouds. In: Monthly Notices of the Royal Astronomical Society. 2019 ; Vol. 483, No. 4. pp. 5623–5641.

Bibtex - Download

@article{10dc3b069e464eb3abf803f8da4a40ed,
title = "Clustering and dynamic decoupling of dust grains in turbulent molecular clouds",
abstract = "We present high-resolution (1024 3) simulations of super-/hypersonic isothermal hydrodynamic turbulence inside an interstellar molecular cloud (resolving scales of typically 20-100 au), including a multidisperse population of dust grains, i.e. a range of grain sizes is considered. Due to inertia, large grains (typical radius a ≳ 1.0μm) will decouple from the gas flow, while small grains (al∼ 0.1μm) will tend to better trace the motions of the gas. We note that simulations with purely solenoidal forcing show somewhat more pronounced decoupling and less clustering compared to simulations with purely compressive forcing. Overall, small and large grains tend to cluster, while intermediate-size grains show essentially a random isotropic distribution. As a consequence of increased clustering, the grain-grain interaction rate is locally elevated; but since small and large grains are often not spatially correlated, it is unclear what effect this clustering would have on the coagulation rate. Due to spatial separation of dust and gas, a diffuse upper limit to the grain sizes obtained by condensational growth is also expected, since large (decoupled) grains are not necessarily located where the growth species in the molecular gas is.",
keywords = "dust, extinction, hydrodynamics, instabilities",
author = "Lars Mattsson and Akshay Bhatnagar and Frederick Gent and Beatriz Villarroel",
year = "2019",
month = "3",
day = "11",
doi = "10.1093/mnras/sty3369",
language = "English",
volume = "483",
pages = "5623–5641",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
number = "4",

}

RIS - Download

TY - JOUR

T1 - Clustering and dynamic decoupling of dust grains in turbulent molecular clouds

AU - Mattsson, Lars

AU - Bhatnagar, Akshay

AU - Gent, Frederick

AU - Villarroel, Beatriz

PY - 2019/3/11

Y1 - 2019/3/11

N2 - We present high-resolution (1024 3) simulations of super-/hypersonic isothermal hydrodynamic turbulence inside an interstellar molecular cloud (resolving scales of typically 20-100 au), including a multidisperse population of dust grains, i.e. a range of grain sizes is considered. Due to inertia, large grains (typical radius a ≳ 1.0μm) will decouple from the gas flow, while small grains (al∼ 0.1μm) will tend to better trace the motions of the gas. We note that simulations with purely solenoidal forcing show somewhat more pronounced decoupling and less clustering compared to simulations with purely compressive forcing. Overall, small and large grains tend to cluster, while intermediate-size grains show essentially a random isotropic distribution. As a consequence of increased clustering, the grain-grain interaction rate is locally elevated; but since small and large grains are often not spatially correlated, it is unclear what effect this clustering would have on the coagulation rate. Due to spatial separation of dust and gas, a diffuse upper limit to the grain sizes obtained by condensational growth is also expected, since large (decoupled) grains are not necessarily located where the growth species in the molecular gas is.

AB - We present high-resolution (1024 3) simulations of super-/hypersonic isothermal hydrodynamic turbulence inside an interstellar molecular cloud (resolving scales of typically 20-100 au), including a multidisperse population of dust grains, i.e. a range of grain sizes is considered. Due to inertia, large grains (typical radius a ≳ 1.0μm) will decouple from the gas flow, while small grains (al∼ 0.1μm) will tend to better trace the motions of the gas. We note that simulations with purely solenoidal forcing show somewhat more pronounced decoupling and less clustering compared to simulations with purely compressive forcing. Overall, small and large grains tend to cluster, while intermediate-size grains show essentially a random isotropic distribution. As a consequence of increased clustering, the grain-grain interaction rate is locally elevated; but since small and large grains are often not spatially correlated, it is unclear what effect this clustering would have on the coagulation rate. Due to spatial separation of dust and gas, a diffuse upper limit to the grain sizes obtained by condensational growth is also expected, since large (decoupled) grains are not necessarily located where the growth species in the molecular gas is.

KW - dust

KW - extinction

KW - hydrodynamics

KW - instabilities

UR - http://www.scopus.com/inward/record.url?scp=85062280568&partnerID=8YFLogxK

U2 - 10.1093/mnras/sty3369

DO - 10.1093/mnras/sty3369

M3 - Article

VL - 483

SP - 5623

EP - 5641

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -

ID: 28242367