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Related papers: Clouds, Clumps, Cores & Comets - a Cosmic Chemical…

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We couple a simplified model for the galactic chemical evolution, with software that models the condensation of dust in protoplanetary disks and software that models the interior structure of planets in order to estimate the effects that…

Earth and Planetary Astrophysics · Physics 2025-07-16 Jason H. Steffen , Cody Shakespeare , Robert Royer , David Rice , Allona Vazan

Astrochemistry is a well-established multidisciplinary field devoted to study molecules in space. While most astrochemists are oriented to observe molecules in the gas phase and reproduce their abundances by modeling the physical conditions…

Astrophysics of Galaxies · Physics 2025-12-10 Guillermo M. Muñoz Caro , Héctor Carrascosa de Lucas , Rafael Martín-Doménech

Electron temperatures, densities, ionic and elemental abundances of helium, nitrogen, oxygen, argon, sulfur and neon were derived for a sample of bulge planetary nebulae, representative of its intermediate mass population. Using these…

Astrophysics · Physics 2009-11-13 Roberto D. D. Costa , Andre V. Escudero , Walter J. Maciel

The supernova explosion increases cosmic ray and x-ray fluxes in the surrounding interstellar medium. Cosmic ray particles and x-ray radiation penetrate nearby molecular clouds and affect the chemical and thermal evolution of the gas. Here…

Astrophysics of Galaxies · Physics 2019-12-25 A. V. Nesterenok

I describe the scenario of molecular cloud (MC) evolution that has emerged over the past decade or so. MCs can start out as cold atomic clouds formed by compressive motions in the warm neutral medium (WNM) of galaxies. Such motions can be…

Astrophysics of Galaxies · Physics 2010-09-22 Enrique Vazquez-Semadeni

In this paper we review recent progress in our understanding of the chemical evolution of protoplanetary disks. Current observational constraints and theoretical modeling on the chemical composition of gas and dust in these systems are…

Astrophysics of Galaxies · Physics 2015-05-28 Dmitry A. Semenov

Questions regarding how primordial or pristine the comets of the solar system are have been an ongoing controversy. In this review, we describe comets' physical evolution from dust and ice grains in the solar nebula to the contemporary…

Earth and Planetary Astrophysics · Physics 2022-07-27 Jürgen Blum , Dorothea Bischoff , Bastian Gundlach

Low-energy cosmic rays are a fundamental source of ionization for molecular clouds, influencing their chemical, thermal and dynamical evolution. The purpose of this work is to explore the possibility that a low-energy component of…

Solar and Stellar Astrophysics · Physics 2015-05-13 Marco Padovani , Daniele Galli , Alfred E. Glassgold

We have compared the intensity distribution of molecular line emission with that of dust continuum emission, and modeled molecular line profiles in three different preprotostellar cores in order to test how dynamical evolution is related to…

Astrophysics · Physics 2007-05-23 Jeong-Eun Lee , Neal J. Evans , Yancy L. Shirley , Ken'ichi Tatematsu

We present our recently developed 3-dimensional chemodynamical code for galaxy evolution. This code follows the evolution of different galactic components like stars, dark matter and different components of the interstellar medium (ISM),…

Astrophysics · Physics 2009-11-07 P. Berczik , G. Hensler , Ch. Theis , R. Spurzem

Linear analysis of the formation of protostellar cores in planar magnetic interstellar clouds shows that molecular clouds exhibit a preferred length scale for collapse that depends on the mass-to-flux ratio and neutral-ion collision time…

Solar and Stellar Astrophysics · Physics 2015-06-11 Nicole D. Bailey , Shantanu Basu

The physical conditions in molecular clouds control the nature and rate of star formation, with consequences for planet formation and galaxy evolution. The focus of this review is on the conditions that characterize regions of star…

Astrophysics · Physics 2009-10-31 Neal J. Evans

The rapid advances in observations of the different populations of exoplanets, the characterization of their host stars and the links to the properties of their planetary systems, the detailed studies of protoplanetary disks, and the…

Earth and Planetary Astrophysics · Physics 2018-12-05 Ralph E. Pudritz , Alex J. Cridland , Matthew Alessi

In this series of lectures I discuss the basic principles and the modelling of the chemical evolution of galaxies. In particular, I present models for the chemical evolution of the Milky Way galaxy and compare them with the available…

Astrophysics · Physics 2007-05-23 F. Matteucci

Clouds also form in atmospheres of planets that orbit other stars than our Sun, in so-called extrasolar planets or exoplanets. Exoplanet atmospheres can be chemically extremely rich. Exoplanet clouds are therefor made of a mix of materials…

Earth and Planetary Astrophysics · Physics 2019-06-12 Christiane Helling

In this paper, we investigate the extent to which observations of molecular clouds can correctly identify and measure star-forming clumps. We produced a synthetic column density map and a synthetic spectral-line data cube from the simulated…

Astrophysics of Galaxies · Physics 2012-08-23 Rachel L. Ward , James Wadsley , Alison Sills , Nicolas Petitclerc

We demonstrate that the observationally inferred rapid onset of star formation after parental molecular clouds have assembled can be achieved by flow-driven cloud formation of atomic gas, using our previous three-dimensional numerical…

Astrophysics · Physics 2009-11-13 Fabian Heitsch , Lee Hartmann

Aims. We study the effect of large scale dynamics on the molecular composition of the dense interstellar medium during the transition between diffuse to dense clouds. Methods. We followed the formation of dense clouds (on sub-parsec scales)…

Astrophysics of Galaxies · Physics 2018-04-11 M. Ruaud , V. Wakelam , P. Gratier , I. A. Bonnell

Dense core collisions, previously regarded as minor in star formation, are proposed to play a significant role in structure formation around protostellar envelopes and binary formation. Using archival data of nearby star-forming regions, we…

Astrophysics of Galaxies · Physics 2024-02-20 Yuta Yano , Fumitaka Nakamura , Shinichi W. Kinoshita

Standard models for the chemical evolution of the Galaxy are reviewed with particular emphasis on the history of the abundance gradients in the disk. The effects on the disk structure and metallicity of gas accretion are discussed, showing…

Astrophysics · Physics 2007-05-23 M. Tosi