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Related papers: Modeling Observational Signatures of Disk-Driven O…

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We use a multi-dimensional Monte Carlo code to compute X-ray spectra for a variety of active galactic nucleus (AGN) disk-wind outflow geometries. We focus on the formation of blue-shifted absorption features in the Fe K band and show that…

Astrophysics · Physics 2009-11-13 S. A. Sim , K. S. Long , L. Miller , T. J. Turner

In the subset of luminous, early-type stars with strong, large-scale magnetic fields and moderate to rapid rotation, material from the star's radiatively driven stellar wind outflow becomes trapped by closed magnetic loops, forming a…

Solar and Stellar Astrophysics · Physics 2017-12-27 Stanley P. Owocki , Steven R. Cranmer

The winds of ionized gas driven by Active Galactic Nuclei (AGN) can be studied through absorption lines in their X-ray spectra. A recurring feature of these outflows is their broad ionization distribution, including essentially all…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Jonathan Stern , Ehud Behar , Ari Laor , Alexei Baskin , Tomer Holczer

The aim of this paper is to investigate the properties of accretion disks threaded by a weak vertical magnetic field, with a particular focus on the interplay between MHD turbulence driven by the magnetorotational instability (MRI) and…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Sebastien Fromang , Henrik N. Latter , Geoffroy Lesur , Gordon I. Ogilvie

Accretion disk winds are commonly observed in active galactic nuclei (AGN). The winds may be associated with the changing spectral properties of such sources, yet such connections have not been studied in detail so far. This paper presents…

Astrophysics of Galaxies · Physics 2025-04-29 Hagai Netzer

Galactic outflows, driven by active galactic nuclei (AGN), play a crucial role in galaxy formation and in the self-regulated growth of supermassive black holes (BHs). AGN feedback couples to and affects gas, rather than stars, and in many,…

Astrophysics of Galaxies · Physics 2018-04-10 Tilman Hartwig , Marta Volonteri , Gohar Dashyan

We describe an efficient method of calculating the radiation pressure due to spectral lines, including all the terms in the velocity gradient tensor. We apply this method to calculate the two-dimensional, time-dependent structure of winds…

Astrophysics · Physics 2009-10-31 D. Proga , J. M. Stone , J. E. Drew

Protoplanetary disks are the sites of vigorous hydrodynamic processes, such as accretion and outflows, and ultimately establish the conditions for the formation of planets. The properties of disk outflows are often inferred through analysis…

Solar and Stellar Astrophysics · Physics 2024-03-18 Ahmad Nemer , ChangHoon Hahn , Jiaxuan Li , Peter Melchior , Jeremy Goodman

We demonstrate that magnetically-collimated protostellar winds will sweep ambient material into thin, radiative, momentum-conserving shells whose features reproduce those commonly observed in bipolar molecular outflows. We find the typical…

Astrophysics · Physics 2009-10-31 Christopher D. Matzner , Christopher F. McKee

We present 3D adaptive mesh refinement MHD simulations of an isolated galaxy cluster that include injection of kinetic, thermal, and magnetic energy via a central active galactic nucleus (AGN) in order to study and evaluate the role that…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 P. M. Sutter , H. -Y. Yang , P. M. Ricker , G. Foreman , D. Pugmire

We review the main results from line-driven (LD) models of winds from accretion disks in cataclysmic variables (CVs). We consider LD disk wind models in the hydrodynamic (HD) and magnetohydrodynamic (MHD limits. We discuss the basic…

Astrophysics · Physics 2007-05-23 Daniel Proga

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

Radiation pressure on spectral lines is a promising mechanism for powering disc winds from accreting white dwarfs (AWDs) and active galactic nuclei (AGN). However, in radiation-hydrodynamic simulations, overionization reduces line opacity…

Winds arising from galaxies, star clusters, and active galactic nuclei are crucial players in star and galaxy formation, but it has proven remarkably difficult to use observations of them to determine physical properties of interest,…

Astrophysics of Galaxies · Physics 2017-08-30 Mark R. Krumholz , Todd A. Thompson , Eve C. Ostriker , Crystal L. Martin

UltraFast Outflows (UFO) are observed in some active galactic nuclei (AGN), with blueshifted and highly ionised Fe-K absorption features. AGN typically have a UV bright accretion flow, so UV line driving is an obvious candidate for…

High Energy Astrophysical Phenomena · Physics 2020-11-25 Misaki Mizumoto , Mariko Nomura , Chris Done , Ken Ohsuga , Hirokazu Odaka

A physically consistent approach is considered for defining an external magnetic field as needed in computational fluid dynamics problems involving magnetohydrodynamics (MHD). The approach results in simple analytical formulae that can be…

Fluid Dynamics · Physics 2009-11-25 E. V. Votyakov , S. C. Kassinos , X. Albets-Chico

We perform an analytic investigation of the stability of line-driven disk winds, independent of hydrodynamic simulations. Our motive is to determine whether or not line-driven disk winds can account for the wide/broad UV resonance…

Astrophysics · Physics 2011-05-12 Nicolas A. Pereyra , Stanley P. Owocki , D. John Hillier , David A. Turnshek

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

In this chapter, we summarize recent progress on the properties of accretion disks when the accretion rate exceeds the so-called Eddington limit based on multi-dimensional radiation magnetohydrodynamic simulations. We first summarize the…

High Energy Astrophysical Phenomena · Physics 2024-09-02 Yan-Fei Jiang , Lixin Dai

Observations and simulations show that outflows in active galactic nuclei (AGN) contain gas in different phases. To understand their true impact on galaxy evolution, we advocate consistent and unbiased investigation of these multiphase…

Astrophysics of Galaxies · Physics 2018-03-01 Claudia Cicone , Marcella Brusa , Cristina Ramos Almeida , Giovanni Cresci , Bernd Husemann , Vincenzo Mainieri