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Related papers: Evidence of Enhanced Ionization in Protostellar En…

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(abridged) We analyse the evolution of the fractional ionisation in a steady-state protoplanetary disc with a vertical temperature gradient and with gas-grain chemistry including surface reactions. The ionisation due to stellar X-rays,…

Astrophysics · Physics 2009-11-10 D. Semenov , D. Wiebe , Th. Henning

We present detailed gas-phase chemical models for the envelope of the low-mass star-forming region IRAS 16293-2422. By considering both time- and space-dependent chemistry, these models are used to study both the physical structure proposed…

Astrophysics · Physics 2009-11-10 S. D. Doty , F. L. Schoeier , E. F. van Dishoeck

Understanding the role of high-redshift protoclusters in cosmic reionization is essential to unveiling the early stages of structure formation. Using deep imaging and spectroscopy from the James Webb Space Telescope (JWST) JADES Deep Survey…

Astrophysics of Galaxies · Physics 2026-04-29 Qiong Li , Christopher J. Conselice , Duncan Austin , Tom Harvey , Nathan Adams , Vadim Rusakov , Lewi Westcott

We present a study of dense molecular gas kinematics in seventeen nearby protostellar systems using single-dish and interferometric molecular line observations. The non-axisymmetric envelopes around a sample of Class 0/I protostars were…

The paper considers the evolution of the supernova envelopes produced by Population III stars with masses of $M_*\sim 25-200 M_\odot$ located in non-rotating protogalaxies with masses of $M\sim 10^7 M_\odot$ at redshifts $z=12$, with…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-06 E. O. Vasiliev , E. I. Vorobyov , E. E. Matvienko , A. O. Razoumov , Yu. A. Shchekinov

We compute numerical simulations of spherical collapse triggered by a slow increase in external pressure. We compare isothermal models to models including cooling with a simple but self-consistent treatment of the coupling between gas,…

Astrophysics · Physics 2009-11-11 P. Lesaffre , A. Belloche , J. -P. Chieze , P. Andre

Even today in our Galaxy, stars form from gas cores in a variety of environments, which may affect the properties of resulting star and planetary systems. Here we study the role of pressure, parameterized via ambient clump mass surface…

Astrophysics of Galaxies · Physics 2015-06-23 Yichen Zhang , Jonathan C. Tan

The physical and chemical conditions in Class 0/I protostars are fundamental in unlocking the protostellar accretion process and its impact on planet formation. The aim is to determine which physical components are traced by different…

We present 1D radiative transfer modelling of the envelopes of a sample of 18 low-mass protostars and pre-stellar cores with the aim of setting up realistic physical models, for use in a chemical description of the sources. The density and…

Astrophysics · Physics 2009-11-07 Jes K. Jorgensen , Fredrik L. Schoeier , Ewine F. van Dishoeck

Abridged abstract: For stars to form, material must fall inwards from core scales through the envelope towards the central protostar. The velocity profile around protostars is poorly constrained. 6 Class 0 protostars and one Class I…

Astrophysics of Galaxies · Physics 2015-06-17 J. C. Mottram , E. F. van Dishoeck , M. Schmalzl , L. E. Kristensen , R. Visser , M. R. Hogerheijde , S. Bruderer

Class I protostars are a bridge between Class 0 protostars, and Class II protoplanetary disks. Recent studies show gaps and rings in the dust distribution of disks younger than 1 Myr, suggesting that planet formation may start already at…

Solar and Stellar Astrophysics · Physics 2022-03-14 S. Mercimek , C. Codella , L. Podio , E. Bianchi , L. Chahine , M. Bouvier , A. Lopez-Sepulcre , R. Neri , C. Ceccarelli

We present the first gas-grain astrochemical model of the NGC 2264 CMM3 protostellar core. The chemical evolution of the core is affected by changing its physical parameters such as the total density and the amount of gas-depletion onto…

Astrophysics of Galaxies · Physics 2017-03-21 Zainab Awad , Osama M. Shalabeia

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

The latest developments in astrochemistry have shown how some molecular species can be used as a tool to study the early stages of the solar-type star formation process. Among them, the more relevant species are the interstellar complex…

Solar and Stellar Astrophysics · Physics 2019-11-21 Eleonora Bianchi , Cecilia Ceccarelli , Claudio Codella , Juan Enrique-Romero , Cecile Favre , Bertrand Lefloch

Context: Intermediate mass protostars provide a bridge between low- and high-mass protostars. Furthermore, they are an important component of the UV interstellar radiation field. Despite their relevance, little is known about their…

NGC 1333 IRAS 4A and IRAS 4B sources are among the best studied Stage 0 low-mass protostars which are driving prominent bipolar outflows. Most studies have so far concentrated on the colder parts (T<30K) of these regions. The aim is to…

We discuss recent models of chemical evolution in the developing and collapsing protostellar envelopes associated with low-mass star formation. In particular, the effects of depletion of gas-phase molecules onto grain surfaces is…

Astrophysics · Physics 2007-05-23 Edwin A. Bergin

Ionization-recombination balance in dense interstellar and circumstellar environments is a key factor for a variety of important physical processes, such as chemical reactions, dust charging and coagulation, coupling of the gas with…

Solar and Stellar Astrophysics · Physics 2016-12-14 A. V. Ivlev , V. V. Akimkin , P. Caselli

Ions and electrons play an important role in various stages of the star formation process. By following the magnetic field of their environment and interacting with neutral species, they slow down the gravitational collapse of the…

Solar and Stellar Astrophysics · Physics 2018-05-02 D. Quénard , S. Bottinelli , E. Caux , V. Wakelam