中文
相关论文

相关论文: Magnetic pressure support and accretion disk spect…

200 篇论文

The global development of magnetohydrodynamic turbulence in an accretion disk is studied within a simplified disk model that omits vertical stratification. Starting with a weak vertical seed field, a saturated state is obtained after a few…

天体物理学 · 物理学 2009-10-30 Philip J. Armitage

Studying accretion phenomena is a window into understanding most heavenly bodies, from the birth of stars to Active galactic nuclei(AGN). We would adopt the effect of the radiation pressure which reduces accretion rates M on the accretion…

星系天体物理 · 物理学 2023-01-03 Hongsu Kim , Uicheol Jang , Yu Yi

We present a linear analysis of the vertical structure and growth of the magnetorotational instability in stratified, weakly ionised accretion discs, such as protostellar and quiescent dwarf novae systems. The method includes the effects of…

天体物理学 · 物理学 2009-11-10 Raquel Salmeron , Mark Wardle

According to the standard thin disc theory, it is predicted that the radiation-pressure-dominated inner region of a thin disc is thermally unstable, while observations suggest that it is common for a thin disc of more than 0.01 Eddington…

高能天体物理现象 · 物理学 2023-09-25 Yu Zhao , Xiao-Hong Yang , Li Xue , Shuang-Liang Li

The status of our current understanding of angular momentum transport in accretion disks is reviewed. The last decade has seen a dramatic increase both in the recognition of key physical processes and in our ability to carry through direct…

天体物理学 · 物理学 2008-11-26 Steven A. Balbus

Protoplanetary disks are believed to accrete onto their central T Tauri star because of magnetic stresses. Recently published shearing box simulations indicate that Ohmic resistivity, ambipolar diffusion and the Hall effect all play…

地球与行星天体物理 · 物理学 2015-06-23 Oliver Gressel , Neal J. Turner , Richard P. Nelson , Colin P. McNally

I discuss the results of simplified three dimensional magnetohydrodynamic simulations of the boundary layer between a disc and a non-rotating, unmagnetized star. Strong magnetic fields, possibly approaching equipartition with the thermal…

天体物理学 · 物理学 2007-05-23 Philip J. Armitage

We present relativistic, radiation magnetohydrodynamic simulations of supercritical neutron star accretion columns in Cartesian geometry, including temperature-dependent, polarization-averaged Rosseland mean opacities accounting for…

高能天体物理现象 · 物理学 2023-07-26 Xin Sheng , Lizhong Zhang , Omer Blaes , Yan-Fei Jiang

Magnetic fields in accretion disks play a dominant role during the star formation process but have hitherto been observationally poorly constrained. Field strengths have been inferred on T Tauri stars themselves and possibly in the…

Magnetic fields are important for accretion disc structure. Magnetic fields in a disc system may be transported with the accreted matter. They can be associated with either the central body and/or jet, and be fossil or dynamo excited in…

高能天体物理现象 · 物理学 2016-03-23 David Moss , Dmitri Sokoloff , Valery Suleimanov

This study investigates the thermal stability of thin accretion disks in high-energy astrophysical systems, incorporating the effects of magnetic fields, winds, and coronae. We analyze how these factors influence disk stability, focusing on…

高能天体物理现象 · 物理学 2025-01-28 Arezoo Tajmohamadi , Shahram Abbassi

Strongly magnetized accretion discs around black holes have attractive features that may explain enigmatic aspects of X-ray binary behaviour. The structure and evolution of these discs are governed by a dynamo-like mechanism, which channels…

高能天体物理现象 · 物理学 2016-02-03 Greg Salvesen , Jacob B. Simon , Philip J. Armitage , Mitchell C. Begelman

abridged: We use XSCORT, together with the hydrodynamic accretion disc wind simulation from Proga & Kallman (2004), to calculate the impact that the accretion disk wind has on the X-ray spectrum from a 1E8 solar mass black hole Active…

天体物理学 · 物理学 2011-02-11 N. J. Schurch , C. Done , D. Proga

A protostellar disk is threaded by a static magnetic field that is perpendicular to the disk-surface. The magnetic field acts to brake the protostellar disk and cause the disk material to move towards the protostar. General analytic…

太阳与恒星天体物理 · 物理学 2026-02-19 Kurt Liffman

This paper presents a series of stratified shearing-box simulations of collisionless accretion disks in the recently developed framework of kinetic magnetohydrodynamics (MHD), which can handle finite non-gyrotropy of a pressure tensor.…

高能天体物理现象 · 物理学 2017-06-28 Kota Hirabayashi , Masahiro Hoshino

Polarisation measurements by the Event Horizon Telescope from M87$^{\ast}$ and Sgr A$^\ast$ suggest that there is a dynamically strong, ordered magnetic field, typical of what is expected of a magnetically arrested accretion disk (MAD). In…

高能天体物理现象 · 物理学 2024-07-29 León Salas , Gibwa Musoke , Koushik Chatterjee , Sera Markoff , Oliver Porth , Matthew Liska , Bart Ripperda

Spiral density waves are known to exist in many astrophysical disks, potentially affecting disk structure and evolution. We conduct a numerical study of the effects produced by a density wave, evolving into a shock, on the characteristics…

地球与行星天体物理 · 物理学 2018-02-28 Lev Arzamasskiy , Roman R. Rafikov

The conventional accretion disk lore is that magnetized turbulence is the principal angular momentum transport process that drives accretion. However, when dynamically important large-scale magnetic fields thread an accretion disk, they can…

Despite extensive study, the mechanisms by which Be star disks acquire high densities and angular momentum while displaying variability on many time scales are still far from clear. In this paper, we discuss how magnetic torquing may help…

天体物理学 · 物理学 2009-11-07 J. P. Cassinelli , J. C. Brown , M. Maheswaran , N. A. Miller , D. C. Telfer

We carried out global three-dimensional resistive magnetohydrodynamic simulations of galactic gaseous disks to investigate how the galactic magnetic fields are amplified and maintained. We adopt a steady axisymmetric gravitational potential…

天体物理学 · 物理学 2009-11-11 Hiromitsu Nishikori , Mami Machida , Ryoji Matsumoto