English
Related papers

Related papers: Effect of grain size distribution and size-depende…

200 papers

We consider the depletion of elements from the interstellar gas onto a population of very small dust grains. Adopting a grain model in which of order 4% of the cosmic C abundance is in grains with radii <= 10 Angstroms, we find that the…

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

We investigate the condition for the formation of micron-sized grains in dense cores of molecular clouds. This is motivated by the detection of the mid-infrared emission from deep inside a number of dense cores, the so-called `coreshine,'…

Astrophysics of Galaxies · Physics 2015-06-16 Hiroyuki Hirashita , Zhi-Yun Li

We propose an updated dust evolution model that focuses on the grain size distribution in a galaxy. We treat the galaxy as a one-zone object and include five main processes (stellar dust production, dust destruction in supernova shocks,…

Astrophysics of Galaxies · Physics 2022-11-30 Hiroyuki Hirashita

Context. Time dependent gas-grain chemistry can help us understand the layered structure of species deposited onto the surface of grains during the lifetime of a protoplanetary disk. The history of trapping important quantities of carbon-…

Solar and Stellar Astrophysics · Physics 2016-11-25 Germán Chaparro Molano , Inga Kamp

Under cold conditions in dense cores, gas-phase molecules and atoms are depleted from the gas-phase to the surface of interstellar grains. Considering the time scales and physical conditions within these cores, a portion of these molecules…

Astrophysics of Galaxies · Physics 2021-08-11 V. Wakelam , E. Dartois , M. Chabot , S. Spezzano , D. Navarro-Almaida , J. -C. Loison , A. Fuente

Icy grains in the interstellar medium and star-formation regions consist of a variety of materials. Such composite grains interact differently with cosmic-ray (CR) particles compared to simple single-material grains. We aim to calculate the…

Astrophysics of Galaxies · Physics 2022-09-21 Juris Kalvans , Juris Roberts Kalnin

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

In regions where stars form, variations in density and temperature can cause gas to freeze-out onto dust grains forming ice mantles, which influences the chemical composition of a cloud. The aim of this paper is to understand in detail the…

Solar and Stellar Astrophysics · Physics 2017-11-08 S. Cazaux , R. Martin-Domenech , Y. J. Chen , G. M. Munoz Caro , C. Gonzalez Diaz

In this paper we present results obtained with the new grain code in Cloudy which underline the strong effect of photo-electric heating by grains in photo-ionized regions. We study the effect that the distribution of grain sizes has on the…

Astrophysics · Physics 2007-05-23 P. A. M. van Hoof , J. C. Weingartner , P. G. Martin , K. Volk , G. J. Ferland

We investigated the effect of time-dependent ice growth on dust grains on the opacity and hence on the dust temperature in a collapsing molecular cloud core, with the aim of quantifying the effect of the dust temperature variations on ice…

Astrophysics of Galaxies · Physics 2024-10-16 O. Sipilä , P. Caselli , M. Juvela

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…

Astrophysics of Galaxies · Physics 2020-04-08 M. Relano , U. Lisenfeld , K. C. Hou , I. De Looze , J. M. Vilchez , R. C. Kennicutt

The temperatures of interstellar dust grains are analyzed using stochastic simulations, taking into account the grain composition and size and the discreteness of the photon flux. [...] The distribution of grain temperatures is calculated…

Astrophysics · Physics 2007-09-21 Kobi Horn , Hagai B. Perets , Ofer Biham

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

Context. We investigate the grain opacity k_gr in the atmosphere of protoplanets. This is important for the planetary mass-radius relation since k_gr affects the H/He envelope mass of low-mass planets and the critical core mass of giant…

Earth and Planetary Astrophysics · Physics 2014-12-10 C. Mordasini

We examine the ability of stellar X-rays to desorb molecules from grains in outer protoplanetary disks. In particular, we consider the possibility of spot heating by X-rays and examine its effectiveness, compared to whole grain heating by…

Astrophysics · Physics 2009-11-07 Joan Najita , Edwin A. Bergin , Joel N. Ullom

To explain grain growth and destruction in warm media, ice mantle formation and sublimation in cold media, and gas line emission spectroscopy, astrochemical models must mimic the gas--solid abundance ratio. Ice-sublimation mechanisms…

Astrophysics of Galaxies · Physics 2024-04-04 F. Kruczkiewicz , F. Dulieu , A. V. Ivlev , P. Caselli , B. M. Giuliano , C. Ceccarelli , P. Theulé

Observed reddening in the circum-galactic medium (CGM) indicates a significant abundance of small grains, of which the origin is still to be clarified. We examine a possible path of small-grain production through shattering of pre-existing…

Astrophysics of Galaxies · Physics 2021-05-26 Hiroyuki Hirashita , Ting-Wen Lan

The mobility of lighter species on the surface of interstellar dust grains plays a crucial role in forming simple through complex molecules. Carbon monoxide is one of the most abundant molecules, its surface diffusion on the grain surface…

Astrophysics of Galaxies · Physics 2022-03-30 Kinsuk Acharyya

We determine the non-equilibrium grain size distribution during the crystallization of a solid in $d$ dimensions at fixed thermodynamic conditions, for the random nucleation and growth model, and in absence of grain coalescence. Two…

Materials Science · Physics 2013-10-25 Kimberly S. Lokovic , Ralf B. Bergmann , Andreas Bill

Stochastic heating of small grains is often mentioned as a primary cause of large infrared (IR) fluxes from star-forming galaxies, e.g. at 24\mu m. If the mechanism does work at a galaxy-wide scale, it should show up at smaller scales as…

Astrophysics of Galaxies · Physics 2015-06-03 Ya. N. Pavlyuchenkov , D. S. Wiebe , V. V. Akimkin , M. S. Khramtsova , Th. Henning