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Related papers: Time evolution of simple molecules during proto-st…

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We present an analysis of Giant Molecular Clouds (GMCs) within hydrodynamic simulations of isolated, low-mass (M* ~ 10^9 M_sol) disc galaxies. We study the evolution of molecular abundances and the implications for CO emission and the X_CO…

Astrophysics of Galaxies · Physics 2016-07-27 Alexander J. Richings , Joop Schaye

We explore the conditions prevailing in primordial planets in the framework of the HGD cosmologies as discussed by Gibson and Schild. The initial stages of condensation of planet-mass H-4He gas clouds in trillion-planet clumps is set at…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 N. Chandra Wickramasinghe , Jamie H. Wallis , Carl H. Gibson , Rudolph E. Schild

Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc. are thought to be intimately related to the nature and evolution of pregalactic structure. In particular…

Astrophysics · Physics 2007-05-23 Tom Abel , Greg L. Bryan , Michael L. Norman

Hot cores and their precursors contain an integrated record of the physics of the collapse process in the chemistry of the ices deposited during that collapse. In this paper, we present results from a new model of the chemistry near high…

Astrophysics · Physics 2009-11-10 S. Viti , M. P. Collings , J. W. Dever , M. R. S. McCoustra , D. A. Williams

We derive the Hydrodynamics for a system of N active, spherical, underdamped particles, interacting through conservative forces. At the microscopic level, we represent the evolution of the particles in terms of the Kramers equation for the…

Statistical Mechanics · Physics 2022-03-15 Umberto Marini Bettolo Marconi , Andrea Puglisi , Lorenzo Caprini

An attempt is made here to revisit structure formation in a proto-stellar cloud during the early phase of evolution. Molecular cloud subjected to a set of various initial conditions in terms of initial temperature and amplitude of azimuthal…

Solar and Stellar Astrophysics · Physics 2015-06-16 Rafil Riaz , Suhail Zaki Farooqui , Siegfried Vanaverbeke

We present semi-analytic dynamical models for giant molecular clouds evolving under the influence of HII regions launched by newborn star clusters. In contrast to previous work, we neither assume that clouds are in virial or energetic…

Astrophysics · Physics 2008-11-26 Mark R. Krumholz , Christopher D. Matzner , Christopher F. McKee

Molecular hydrogen (H$_2$) formation and dissociation are key processes that drive the gas lifecycle in galaxies. Using the SImulating the LifeCycle of Molecular Clouds (SILCC) zoom-in simulation suite, we explore the utility of future…

A numerical hydrodynamical model for the evolution of spherically symmetric collapsing clouds, designed for the calculation of the thermal structure of these objects in both the prestellar and protostellar stages of their evolution, is…

Astrophysics of Galaxies · Physics 2015-06-23 Ya. N. Pavlyuchenkov , A. G. Zhilkin , E. I. Vorobyov , A. M. Fateeva

Planets and their atmospheres are built from gas and solid material in protoplanetary disks. Recent results suggest that solid material like pebbles may contribute significantly to building up planetary atmospheres. In order to link…

Earth and Planetary Astrophysics · Physics 2022-12-14 Christian Eistrup , Thomas Henning

It is now well known that a primordial chemistry, involving light elements produced during the nucleosynthesis period, might develop during the hydrogen post-recombination era. In particular, molecular ions and primordial molecules such as…

Astrophysics · Physics 2011-01-20 D. Puy , M. Signore

In this article we extend the study performed in our previous article on the collapse of primordial objects. We here analyze the behavior of the physical parameters for clouds ranging from $10^7M_\odot$ to $10^{15}M_\odot$. We studied the…

Astrophysics · Physics 2009-10-30 S. R. Oliveira , O. D. Miranda , J. C. N. de Araujo , R. Opher

Observations that resolve nearby galaxies into individual regions across multiple phases of the gas-star formation-feedback ``matter cycle'' have provided a sharp new view of molecular clouds, star formation efficiencies, timescales for…

Astrophysics of Galaxies · Physics 2024-04-01 Eva Schinnerer , Adam K. Leroy

We present a unified model for molecular core formation and evolution, based on numerical simulations of converging, supersonic flows. Our model applies to star formation in GMCs dominated by large-scale turbulence, and contains four main…

Solar and Stellar Astrophysics · Physics 2009-06-25 Hao Gong , Eve C. Ostriker

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

Cool, evolved stars are the main source of chemical enrichment of the interstellar medium (ISM), and understanding their mass loss and structure offers a unique opportunity to study the cycle of matter in the Universe. Pulsation,…

The majority of hydrogen in the interstellar medium (ISM) is in atomic form. The transition from atoms to molecules and, in particular, the formation of the H$_2$ molecule, is a key step in cosmic structure formation en route to stars.…

Astrophysics of Galaxies · Physics 2018-10-31 Pei Zuo , Di Li , J. E. G. Peek , Qiang Chang , Xia Zhang , Nicholas chapman , Paul F. Goldsmith , Zhi-Yu Zhang

This paper presents the first results from a model for chemical evolution that can be applied to N-body cosmological simulations and quantitatively compared to measured stellar abundances from large astronomical surveys. This model…

Astrophysics of Galaxies · Physics 2015-09-29 Brian D. Crosby , Brian W. O'Shea , Timothy C. Beers , Jason Tumlinson

We investigate the formation and evolution of giant molecular clouds (GMCs) in a Milky-Way-like disk galaxy with a flat rotation curve. We perform a series of 3D adaptive mesh refinement (AMR) numerical simulations that follow both the…

Astrophysics · Physics 2009-07-22 Elizabeth J. Tasker , Jonathan C. Tan

The development of models for matter infall from a collapsing molecular cloud is an essential part of numerical studies on the formation and evolution of protoplanetary disks. In this article, the widely used Nakamoto and Nakagawa (1994)…

Earth and Planetary Astrophysics · Physics 2026-02-25 E. R. Redkin , E. I. Vorobyov