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Related papers: Variable accretion in the embedded phase of stella…

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(Abridged) Physical processes such as accretion shocks are thought to be common in the protostellar phase, where the envelope component is still present, and they can release molecules from the dust to the gas phase, altering the original…

We present high-resolution zoom-in simulations of molecular clouds exposed to an interstellar radiation field and cosmic ray ionisation rate up to 1000 times stronger than that of the solar neighbourhood. We detail the evolution of the…

We report on the results of an optical spectroscopic survey designed to confirm the youth and determine the spectral types among a sample of young stellar object (YSO) candidates in the Serpens Molecular Cloud. We observed 150 infrared…

We have studied numerically the evolution of protostellar disks around intermediate and upper mass T Tauri stars (0.25 M_sun < M_st < 3.0 M_sun) that have formed self-consistently from the collapse of molecular cloud cores. In the T Tauri…

Astrophysics · Physics 2009-11-13 E. I. Vorobyov , Shantanu Basu

We investigate the response of an accretion disk to the presence of a perturbing protoplanet embedded in the disk through time dependent hydrodynamical simulations. The disk is treated as a two-dimensional viscous fluid and the planet is…

Astrophysics · Physics 2009-11-11 Wilhelm Kley , Gerben Dirksen

We compare eighteen binary systems with precisely determined radii and masses from 23 to 1.1 M_sol, and stellar evolution models produced with our newly revised code TYCHO. ``Overshooting'' and rotational mixing were suppressed in order to…

Astrophysics · Physics 2009-11-06 P. A. Young , E. E. Mamajek , David Arnett , James Liebert

One dimensional, convective, vertical structure models and one dimensional, time dependent, radial diffusion models are combined to create a self-consistent picture in which FU~Orionis outbursts occur in young stellar objects (YSOs) as the…

Astrophysics · Physics 2009-10-22 K. R. Bell , D. N. C. Lin

More and more observations indicate that young star clusters could retain imprints of their formation process. In particular, the degree of substructuring and rotation are possibly the direct result of the collapse of the parent molecular…

Astrophysics of Galaxies · Physics 2020-06-17 Alessandro Ballone , Michela Mapelli , Ugo N. Di Carlo , Stefano Torniamenti , Mario Spera , Sara Rastello

Context: Protoplanetary discs are known to form around nascent stars from their parent molecular cloud as a result of angular momentum conservation. As they progressively evolve and dissipate, they also form planets. While a lot of modeling…

Solar and Stellar Astrophysics · Physics 2024-03-26 J. Mauxion , G. Lesur , S. Maret

We have surveyed 84 Class 0, Class I, and flat-spectrum protostars in mid-infrared [Si II], [Fe II] and [S I] line emission, and 11 of these in far-infrared [O I] emission. We use the results to derive their mass outflow rates. Thereby we…

Complex turbulent motions are ubiquitously observed in many astrophysical systems. Their origin, however, is still poorly understood. When cosmic structures form, they grow in mass via accretion from the surrounding environment. We propose…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Ralf S. Klessen , Patrick Hennebelle

We model gas inflow patterns onto circumstellar disks and the evolution of the pseudodisk using three-dimensional resistive MHD simulations. Starting from a prestellar core without turbulence and with a misalignment between the initial…

Solar and Stellar Astrophysics · Physics 2026-02-10 Masahiro N. Machida , Shingo Hirano , Shantanu Basu

Variability is a defining characteristic of young low-mass stars that are still accreting material from their primordial protoplanetary disk. Here we present the largest \textit{HST} variability study of Classical T Tauri stars (CTTS) to…

Solar and Stellar Astrophysics · Physics 2019-04-10 Connor Robinson , Catherine Espaillat

Aims. To understand the roles of infall and protostellar evolution on the envelopes of massive young stellar objects (YSOs). Methods. The chemical evolution of gas and dust is traced, including infall and realistic source evolution. The…

Astrophysics · Physics 2009-11-11 S. D. Doty , E. F. van Dishoeck , J. C. Tan

A clear understanding of the chemical processing of matter, as it is transferred from a molecular cloud to a planetary system, depends heavily on knowledge of the physical conditions endured by gas and dust as these accrete onto a disk and…

Astrophysics · Physics 2007-05-23 David W. Koerner

Accretion onto Classical T Tauri stars is thought to take place through the action of magnetospheric processes, with gas in the inner disk being channeled onto the star's surface by the stellar magnetic field lines. Young stars are known to…

Solar and Stellar Astrophysics · Physics 2017-04-05 Connor Robinson , James Owen , Catherine Espaillat , Fred Adams

In this article, we proceed to study convection as a possible factor of episodic accretion in protoplanetary disks. Within the model presented in Article~I, the accretion history is analyzed at different rates and areas of matter inflow…

Solar and Stellar Astrophysics · Physics 2020-09-17 L. A. Maksimova , Ya. N. Pavlyuchenkov , A. V. Tutukov

We present radiation hydrodynamics simulations of the collapse of massive pre-stellar cores. We treat frequency dependent radiative feedback from stellar evolution and accretion luminosity at a numerical resolution down to 1.27 AU. In the…

Solar and Stellar Astrophysics · Physics 2011-05-12 Rolf Kuiper , Hubert Klahr , Henrik Beuther , Thomas Henning

We model the vertical structure of magnetized accretion disks subject to viscous and resistive heating, and irradiation by the central star. We apply our formalism to the radial structure of magnetized accretion disks threaded by a poloidal…

Astrophysics of Galaxies · Physics 2016-01-27 S. Lizano , C. Tapia , Y. Boehler , P. D'Alessio