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We present models of photometric evolution of galaxies in which the effects of a dusty interstellar medium have been included with particular care. A chemical evolution code follows the star formation rate, the gas fraction and the…

Astrophysics · Physics 2007-05-23 Laura Silva , Gian Luigi Granato , Alessandro Bressan , Luigi Danese

Formation of interstellar clouds as a consequence of thermal instability is studied using two-dimensional two-fluid magnetohydrodynamic simulations. We consider the situation of converging, supersonic flows of warm neutral medium in the…

Astrophysics of Galaxies · Physics 2015-05-14 Tsuyoshi Inoue , Shu-ichiro Inutsuka

The desorption of molecular species from ice mantles back into the gas phase in molecular clouds results from a variety of very poorly understood processes. We have investigated three mechanisms; desorption resulting from H_2 formation on…

Astrophysics · Physics 2009-11-13 J. F. Roberts , J. M. C. Rawlings , S. Viti , D. A. Williams

We apply gravity-based and density-based methods to identify clouds in numerical simulations of the star-forming, three-phase interstellar medium (ISM), and compare their properties and their global correlation with the star formation rate…

Astrophysics of Galaxies · Physics 2020-07-29 S. Alwin Mao , Eve C. Ostriker , Chang-Goo Kim

Experimental results on the formation of molecular hydrogen on amorphous silicate surfaces are presented and analyzed using a rate equation model. The energy barriers for the relevant diffusion and desorption processes are obtained. They…

Molecular outflows contributing to the matter cycle of star forming galaxies are now observed in small and large systems at low and high redshift. Their physical origin is still unclear. In most theoretical studies only warm ionised/neutral…

Astrophysics of Galaxies · Physics 2021-05-28 Philipp Girichidis , Thorsten Naab , Stefanie Walch , Thomas Berlok

We perform linear analysis of thermal instability in a contracting large cloud filled with warm HI gas and investigate the effect of metallicity and radiation flux. When the cloud reaches critical density n_f, the cloud fragments into cool,…

Astrophysics · Physics 2009-10-31 Motomichi Tashiro , Ryoichi Nishi

Investigating the chemical complexity of the interstellar medium (ISM) is key for understanding its physical nature and evolution. In this work, we study parsec-scale interstellar dust clouds in the neutral ISM of the Milky Way using two…

Astrophysics of Galaxies · Physics 2026-04-29 T. Ramburuth-Hurt , A. De Cia , J. -K. Krogager , C. Ledoux , A. J. Fox

In the Galactic fountain scenario, supernovae and/or stellar winds propel material into the Galactic halo. As the material cools, it condenses into clouds. By using FLASH three-dimensional magnetohydrodynamic simulations, we model and study…

Astrophysics of Galaxies · Physics 2014-11-20 Kyujin Kwak , Robin L. Shelton , Elizabeth A. Raley

Molecular hydrogen has an important role in the early stages of star formation as well as in the production of many other molecules that have been detected in the interstellar medium. In this review we show that it is now possible to study…

Cosmic dust grains are one of the fundamental ingredients of the interstellar medium (ISM). In spite of their small contribution to the total mass budget, dust grains play a significant role in the physical and chemical evolution of…

Astrophysics of Galaxies · Physics 2022-02-09 Angelos Nersesian , Maarten Baes , Suzanne C. Madden

Knowledge of the molecular component of the ISM is fundamental to understand star formation. The H2 component appears to dominate the gas mass in the inner parts of galaxies, while the HI component dominates in the outer parts. Observation…

Astrophysics · Physics 2009-10-31 F. Combes

Volume density is a key physical quantity controlling the evolution of the interstellar medium (ISM) and star formation, but it cannot be accessed directly by observations of molecular clouds. We aim at estimating the volume density…

Astrophysics of Galaxies · Physics 2025-05-15 Jan H. Orkisz , Jouni Kainulainen

The early stages of star formation are closely related to the ambient conditions in the interstellar medium. Important questions such as dust abundance, size distribution, temperature distribution, fraction of molecular gas, fraction of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 F. P. Israel

We investigate the sources and amount of dust in early galaxies. We discuss dust nucleation in stellar atmospheres using published extended atmosphere models, stellar evolution tracks and nucleation conditions and conclude that the (TPAGB)…

Astrophysics · Physics 2009-11-07 H L. Morgan , M G. Edmunds

The formation of molecular clouds out of HI gas is the first step toward star formation. Its metallicity dependence plays a key role to determine star formation through the cosmic history. Previous theoretical studies with detailed chemical…

Astrophysics of Galaxies · Physics 2023-08-29 Masato I. N. Kobayashi , Kazunari Iwasaki , Kengo Tomida , Tsuyoshi Inoue , Kazuyuki Omukai , Kazuki Tokuda

We have developed a complete model of the hydrogen molecule as part of the spectral simulation code Cloudy. Our goal is to apply this to spectra of high-redshift star-forming regions where H2 absorption is seen, but where few other details…

Astrophysics · Physics 2009-11-13 Gargi Shaw , G. J. Ferland , R. Srianand , N. P. Abel

Many theoretical and laboratory studies predict H2 to be formed in highly excited ro-vibrational states. The consequent relaxation of excited levels via a cascade of infrared transitions might be observable in emission from suitable…

Astrophysics of Galaxies · Physics 2015-05-20 Farahjabeen Islam , Cesare Cecchi-Pestellini , Serena Viti , Silvia Casu

Comets are remnants of the icy planetesimals that formed beyond the ice line in the Solar Nebula. Growing from micrometre-sized dust and ice particles to km-sized objects is, however, difficult because of growth barriers and time scale…

Earth and Planetary Astrophysics · Physics 2016-03-02 S. Lorek , B. Gundlach , P. Lacerda , J. Blum

Interstellar dust links the formation of the first stars to the rocky planet we inhabit by playing a pivotal role in the cooling and fragmentation of molecular clouds, and catalyzing the formation of water and organic molecules. Despite its…

Astrophysics of Galaxies · Physics 2024-10-21 Danial Langeroodi , Jens Hjorth , Andrea Ferrara , Christa Gall