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The evolution of star-forming regions and their thermal balance are strongly influenced by their chemical composition, that, in turn, is determined by the physico-chemical processes that govern the transition between the gas phase and the…

The discovery of a low-mass star with such low metallicity as < 4.5x10^{-5} Z_sun reveals the critical role of dust in the formation of extremely metal-poor stars. In this paper we explore the effect of the growth of dust grains through…

Solar and Stellar Astrophysics · Physics 2015-06-11 Takaya Nozawa , Takashi Kozasa , Ken'ichi Nomoto

Context. While radiative cooling of interstellar grains is a well-known process, little detail is known about the cooling of grains with an icy mantle that contains volatile adsorbed molecules. Aims. We explore basic details for the cooling…

Astrophysics of Galaxies · Physics 2020-02-05 Juris Kalvans , Juris Roberts Kalnin

Molecular oxygen has been the subject of many observational searches as chemical models predicted it to be a reservoir of oxygen. Although it has been detected in two regions of the interstellar medium, its rarity is a challenge for…

Astrophysics of Galaxies · Physics 2019-06-04 V. Wakelam , M. Ruaud , P. Gratier , I. A. Bonnell

The molecular evolution that occurs in collapsing prestellar cores is investigated. To model the dynamics, we adopt the Larson-Penston (L-P) solution and analogues with slower rates of collapse. For the chemistry, we utilize the new…

Astrophysics · Physics 2009-11-07 Yuri Aikawa , Nagayoshi Ohashi , Eric Herbst

Advanced telescopes, such as ALMA and JWST, are likely to show that the chemical universe may be even more complex than currently observed, requiring astrochemical modelers to improve their models to account for the impact of new data.…

Astrophysics of Galaxies · Physics 2017-08-07 E M Penteado , C Walsh , H M Cuppen

We investigate the cosmological evolution of interstellar dust with a semi-analytical galaxy formation model ($\nu^2$GC), focusing on the evolution of grain size distribution. The model predicts the statistical properties of dust mass and…

Astrophysics of Galaxies · Physics 2022-10-13 Ryu Makiya , Hiroyuki Hirashita

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

In the earliest phases of star-forming clouds, stable molecular species, such as CO, are important coolants in the gas phase. Depletion of these molecules on dust surfaces affects the thermal balance of molecular clouds and with that their…

Astrophysics of Galaxies · Physics 2016-01-27 S. Hocuk , S. Cazaux , M. Spaans , P. Caselli

The quantity of NH3 produced on grain surfaces in the prestellar core is thought to be one of the determining factors regarding the chemical complexity achievable at later stages of stellar birth. In order to investigate how this quantity…

Astrophysics of Galaxies · Physics 2020-12-09 Azrael A. von Procházka , T. J. Millar

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 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.…

Solar and Stellar Astrophysics · Physics 2016-12-07 M. S. Murga , S. A. Khoperskov , D. S. Wiebe

The evaporation of molecules from dust grains is crucial to understand some key aspects of the star- and the planet-formation processes. During the warm-up phase the presence of young protostellar objects induces molecules to evaporate from…

Astrophysics of Galaxies · Physics 2020-11-25 T. Grassi , S. Bovino , P. Caselli , G. Bovolenta , S. Vogt-Geisse , B. Ercolano

We investigate molecular evolution in a star-forming core that is initially a hydrostatic starless core and collapses to form a low-mass protostar. The results of a one-dimensional radiation-hydrodynamics calculation are adopted as a…

Astrophysics · Physics 2009-11-13 Yuri Aikawa , Valentine Wakelam , Robin T. Garrod , Eric Herbst

In this analysis we illustrate how the relatively new emission mechanism known as spinning dust can be used to characterize dust grains in the interstellar medium. We demonstrate this by using spinning dust emission observations to…

The effect of grain size on the flow stress of FCC polycrystals is analyzed by means of a multiscale strategy based on computational homogenization of the polycrystal aggregate. The mechanical behavior of each crystal is given by a…

Materials Science · Physics 2018-02-09 S. Haouala , J. Segurado , J. LLorca

Interstellar ices are largely composed of frozen water. It is important to derive fundamental parameters for H$_2$O ice such as absorption and scattering opacities for which accurate complex refractive indexes are needed. The primary goal…

Instrumentation and Methods for Astrophysics · Physics 2023-12-20 W. R. M. Rocha , M. G. Rachid , M. K. McClure , J. He , H. Linnartz

Interstellar dust spans a wide range in size distribution, ranging from ultrasmall grains of a few Angstroms to micrometer-size grains. While the presence of nanometer-size dust grains in the Galactic interstellar medium was speculated six…

Astrophysics of Galaxies · Physics 2018-11-14 Yanxia Xie , Luis C. Ho , Aigen Li , Jinyi Shangguan

The thermal structure of a protoplanetary disc is regulated by the opacity that dust grains provide. However, previous works have often considered simplified prescriptions for the dust opacity in hydrodynamical disc simulations, e.g. by…

Earth and Planetary Astrophysics · Physics 2020-08-19 Sofia Savvidou , Bertram Bitsch , Michiel Lambrechts

Context. The largest grains (0.5-1 micron) in the interstellar size distribution are efficient in scattering near- and mid-infrared radiation. These wavelengths are therefore particularly well suited to probe the still uncertain high-end of…

Astrophysics of Galaxies · Physics 2015-06-17 M. Andersen , J. Steinacker , W-F. Thi , L. Pagani , A. Bacmann , R. Paladini
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