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相关论文: Evolution of dust porosity through coagulation and…

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The radiative properties of interstellar dust are affected not only by the grain size distribution but also by the grain porosity. We develop a model for the evolution of size-dependent grain porosity and grain size distribution over the…

星系天体物理 · 物理学 2021-12-08 Hiroyuki Hirashita , Vladimir B. Il'in

We investigate shattering and coagulation of dust grains in turbulent interstellar medium (ISM). The typical velocity of dust grain as a function of grain size has been calculated for various ISM phases based on a theory of grain dynamics…

天体物理学 · 物理学 2009-11-13 Hiroyuki Hirashita , Huirong Yan

Shattering of dust grains in the interstellar medium is a viable mechanism of small grain production in galaxies. We examine the robustness or uncertainty in the theoretical predictions of shattering. We identify $P_1$ (the critical…

星系天体物理 · 物理学 2015-06-15 Hiroyuki Hirashita , Hiroshi Kobayashi

We construct a dust evolution model taking into account the grain size distribution, and investigate what kind of dust processes determine the grain size distribution at each stage of galaxy evolution. In addition to the dust production by…

星系天体物理 · 物理学 2015-06-15 Ryosuke S. Asano , Tsutomu T. Takeuchi , Hiroyuki Hirashita , Takaya Nozawa

In order to theoretically understand dust properties in the circum-galactic medium (CGM), we construct a dust evolution model that incorporates the evolution of grain size distribution. We treat each of the galaxy and the CGM as a one-zone…

星系天体物理 · 物理学 2024-05-02 Hiroyuki Hirashita

Dust grains influence many aspects of star formation, including planet formation, opacities for radiative transfer, chemistry, and the magnetic field via Ohmic, Hall, and ambipolar diffusion. The size distribution of the dust grains is the…

太阳与恒星天体物理 · 物理学 2023-02-08 Pierre Marchand , Ugo Lebreuilly , Mordecai-Mark Mac Low , Vincent Guillet

Dust grains grow in interstellar clouds by accretion and coagulation. In this paper, we focus on these two grain growth processes and numerically investigate how they interplay to increase the grain radii. We show that accretion efficiently…

星系天体物理 · 物理学 2015-06-04 Hiroyuki Hirashita

We investigate the evolution of extinction curves in galaxies based on our evolution model of grain size distribution. In this model, we considered various processes: dust formation by SNe II and AGB stars, dust destruction by SN shocks in…

星系天体物理 · 物理学 2015-06-18 Ryosuke S. Asano , Tsutomu T. Takeuchi , Hiroyuki Hirashita , Takaya Nozawa

Grain growth by the accretion of metals in interstellar clouds (called `grain growth') could be one of the dominant processes that determine the dust content in galaxies. The importance of grain size distribution for the grain growth is…

宇宙学与河外天体物理 · 物理学 2015-05-28 Hiroyuki Hirashita , Tzu-Ming Kuo

We present evolutionary calculations for the size and aromatization degree distributions of interstellar dust grains, driven by their destruction by radiation, collisions with gas particles, and shattering due to grain-grain collisions.…

太阳与恒星天体物理 · 物理学 2016-12-07 M. S. Murga , S. A. Khoperskov , D. S. Wiebe

Planet formation in protoplanetary discs requires dust grains to coagulate from the sub-micron sizes that are found in the interstellar medium into much larger objects. For the first time, we study the growth of dust grains during the…

星系天体物理 · 物理学 2022-06-01 Matthew R. Bate

We compute the evolution of interstellar dust in a hydrodynamic simulation of an isolated disc galaxy. We newly implement the evolution of full grain size distribution by sampling 32 grid points on the axis of the grain radius. We solve it…

星系天体物理 · 物理学 2020-01-08 Shohei Aoyama , Hiroyuki Hirashita , Kentaro Nagamine

In many models of dusty objects in space the grains are assumed to be composite or fluffy. However, the computation of the optical properties of such particles is still a very difficult problem. We analyze how the increase of grain porosity…

天体物理学 · 物理学 2009-11-11 N. V. Voshchinnikov , V. B. Il'in , Th. Henning , D. N. Dubkova

The origin of grain size distribution in the interstellar medium is one of the most fundamental problems in the interstellar physics. In the Milky Way, smaller grains are more abundant in number, but their origins are not necessarily…

星系天体物理 · 物理学 2015-05-19 Hiroyuki Hirashita

The wavelength dependences of interstellar extinction and polarization, supplemented by observed elemental abundances and the spectrum of infrared emission from dust heated by starlight, strongly constrain dust models. One dust model that…

星系天体物理 · 物理学 2009-03-11 B. T. Draine

(abridged) We aim to predict the most important parameters for grain-grain collision outcomes for models of interstellar grain population evolution on astrophysical scales: the threshold velocity above which colliding grains shatter, the…

Dust is formed out of stellar material and is constantly affected by different mechanisms occurring in the ISM. Dust grains behave differently under these mechanisms depending on their sizes, and therefore the dust grain size distribution…

星系天体物理 · 物理学 2020-04-08 M. Relano , U. Lisenfeld , K. C. Hou , I. De Looze , J. M. Vilchez , R. C. Kennicutt

In protoplanetary discs, the coagulation of dust grains into large aggregates still remains poorly understood. Grain porosity appears to be a promising solution to allow the grains to survive and form planetesimals. Furthermore, dust…

地球与行星天体物理 · 物理学 2023-01-06 Stéphane Michoulier , Jean-François Gonzalez

We model the effect of grain size distribution in a galaxy on the evolution of CO and H$_2$ abundances. The formation and dissociation of CO and H$_2$ in typical dense clouds are modelled in a manner consistent with the grain size…

星系天体物理 · 物理学 2023-05-10 Hiroyuki Hirashita

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…

星系天体物理 · 物理学 2020-04-08 Hiroyuki Hirashita , Thiem Hoang
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