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Signatures of "evaporative" winds from exo-planets on short (hot) orbits around their host star have been observed in a number of systems. In this paper we present global AMR simulations that track the launching of the winds, their…

Earth and Planetary Astrophysics · Physics 2017-01-18 Jonathan Carroll-Nellenback , Adam Frank , Baowei Liu , Alice C. Quillen , Eric G. Blackman , Ian Dobbs-Dixon

We have computed new stellar evolution models that include the effects of rotation and magnetic torques under different hypothesis. The goal is to test if a single star can sustain in the envelope the rotational velocities needed for the…

Solar and Stellar Astrophysics · Physics 2015-06-18 G. Garcia-Segura , E. Villaver , N. Langer , S. -C. Yoon , A. Manchado

To understand how the circumstellar environments of post-AGB stars develop into planetary nebulae, we initiate a systematic study of 2D axisymmetric hydrodynamic simulations of protoplanetary nebula (pPN) with a modified ZEUS code. The aim…

Solar and Stellar Astrophysics · Physics 2019-10-08 Igor Novikov , Michael Smith

(Abridged) We report results of three dimensional MHD simulations of global accretion disks threaded with weak vertical magnetic fields. We perform the simulations in the spherical coordinates with different temperature profiles and…

Earth and Planetary Astrophysics · Physics 2015-06-17 Takeru K. Suzuki , Shu-ichiro Inutsuka

Protoplanetary disks (PPDs) accrete onto their central T Tauri star via magnetic stresses. When the effect of ambipolar diffusion (AD) is included, and in the presence of a vertical magnetic field, the disk remains laminar between 1-5 au,…

Earth and Planetary Astrophysics · Physics 2017-06-28 Oliver Gressel

Some basic structures in planetary nebulae are modeled as self-organized magnetohydrodynamic (MHD) plasma configurations with radial flow. These configurations are described by time self-similar dynamics, where space and time dependences of…

Astrophysics · Physics 2012-10-18 K. H. Tsui

Describing the large-scale field topology of protoplanetary disks faces significant difficulties and uncertainties. The transport of the large-scale field inside the disk plays an important role in understanding its evolution. We aim to…

Solar and Stellar Astrophysics · Physics 2025-11-26 D. Steiner , L. Gehrig , M. Güdel

Stars and gaseous planets are magnetised objects but the influence of magnetic fields on their tidal responses and dissipation rates has not been well explored. We present the first exploratory nonlinear magnetohydrodynamic (MHD)…

Solar and Stellar Astrophysics · Physics 2024-11-26 Aurélie Astoul , Adrian J. Barker

We explore the poloidal structure of two-dimensional (2D) MHD winds in relation to their potential association with the X-ray warm absorbers (WAs) and the highly-ionized ultra-fast outflows (UFOs) in AGN, in a single unifying approach. We…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Keigo Fukumura , Francesco Tombesi , Demosthenes Kazanas , Chris Shrader , Ehud Behar , Ioannis Contopoulos

The geometrical shapes and the physical properties of stellar wind -- interstellar medium interaction regions form an important stage for studying stellar winds and their embedded magnetic fields as well as cosmic ray modulation. Our goal…

Solar and Stellar Astrophysics · Physics 2015-01-22 Dieter H. Nickeler , Thomas Wiegelmann , Marian Karlicky , Michaela Kraus

We present new analytical solutions for the evolution of protoplanetary discs (PPDs) where magnetohydrodynamic (MHD) wind-driven processes dominate. Our study uses a 1D model which incorporates equations detailing angular momentum…

Astrophysics of Galaxies · Physics 2024-01-19 Mohsen Shadmehri , Fazeleh Khajenabi

Global evolution and dispersal of protoplanetary disks (PPDs) is governed by disk angular momentum transport and mass-loss processes. Recent numerical studies suggest that angular momentum transport in the inner region of PPDs is largely…

Earth and Planetary Astrophysics · Physics 2016-03-09 Xue-Ning Bai , Jiani Ye , Jeremy Goodman , Feng Yuan

Modeling the outflow of planetary atmospheres is important for understanding the evolution of exoplanet systems and for interpreting their observations. Modern theoretical models of exoplanet atmospheres become increasingly detailed and…

Earth and Planetary Astrophysics · Physics 2021-06-30 P. B. Isakova , Ya. N. Pavlyuchenkov , E. S. Kalinicheva , V. I. Shematovich

Numerical simulations of outflows formed during the collapse of 100 M_sun cloud cores are presented. We derive a generalised criterion from MHD wind theory to analyse the launching mechanism of these outflows. The criterion is successfully…

Solar and Stellar Astrophysics · Physics 2015-05-30 D. Seifried , R. E. Pudritz , R. Banerjee , D. Duffin , R. S. Klessen

Recent high-resolution observations have shown stellar winds to harbour complexities which strongly deviate from spherical symmetry, generally assumed as standard wind model. One such morphology is the archimedean spiral, generally believed…

Solar and Stellar Astrophysics · Physics 2015-07-15 Ward Homan , Leen Decin , Alex de Koter , Allard Jan van Marle , Robin Lombaert , Wouter Vlemmings

Fast line-driven stellar winds play an important role in the evolution of planetary nebulae. We provide global hot star wind models of central stars of planetary nebulae. The models predict wind structure including the mass-loss rates,…

Solar and Stellar Astrophysics · Physics 2020-04-08 J. Krticka , J. Kubat , I. Krtickova

Star formation is ubiquitously associated with the ejection of accretion-powered outflows that carve bipolar cavities through the infalling envelope. This feedback is expected to be important for regulating the efficiency of star formation…

Astrophysics of Galaxies · Physics 2023-04-26 Jan E. Staff , Kei E. I. Tanaka , Jon P. Ramsey , Yichen Zhang , Jonathan C. Tan

Asymmetric shapes and evidence for binary central stars suggest a common-envelope origin for many bipolar planetary nebulae. The bipolar components of the nebulae are observed to expand faster than the rest and the more slowly expanding…

Solar and Stellar Astrophysics · Physics 2022-04-20 P. A. Ondratschek , F. K. Roepke , F. R. N. Schneider , C. Fendt , C. Sand , S. T. Ohlmann , R. Pakmor , V. Springel

We present the first "combined stellar structure and atmosphere models" (CoStar) for massive stars, which consistently treat the entire mass loosing star from the center out to the asymptotic wind velocity. The models use up-to-date input…

Astrophysics · Physics 2007-05-23 D. Schaerer , A. de Koter , W. Schmutz , A. Maeder

During the main phase of evolution of a protoplanetary disk, accretion regulates the inner-disk properties, such as the temperature and mass distribution, and in turn, the physical conditions associated with planet formation. The driving…