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We use numerical hydrodynamics simulations to study line driven winds launched from an accreting alpha-disc. Building on previous work where the driving radiation field is static, we compute a time-dependent radiation flux from the local,…

High Energy Astrophysical Phenomena · Physics 2023-01-25 Anthony Kirilov , Sergei Dyda , Christopher S. Reynolds

We present an analysis of wind absorption in the C II ${\lambda}1335$ doublet towards 40 classical T Tauri stars with archival far-ultraviolet (FUV) spectra obtained by the Hubble Space Telescope. Absorption features produced by fast or…

Solar and Stellar Astrophysics · Physics 2021-11-24 Ziyan Xu , Gregory J. Herczeg , Christopher M. Johns-Krull , Kevin France

Line-driven winds from hot stars and accretion disks are thought to adopt a unique, critical solution which corresponds to maximum mass loss rate and a particular velocity law. We show that in the presence of negative velocity gradients,…

Astrophysics · Physics 2009-10-31 Achim Feldmeier , Isaac Shlosman

Recent interpretations of narrow, variable absorption lines detected in some Type Ia supernovae suggest that their progenitors are surrounded by dense, circumstellar material. Similar variations detected in the symbiotic recurrent nova…

High Energy Astrophysical Phenomena · Physics 2016-02-03 Richard A. Booth , Shazrene Mohamed , Philipp Podsiadlowski

The Chandra and XMM-Newton X-ray telescopes have led to numerous advances in the study and understanding of astrophysical X-ray sources. Particularly important has been the much increased spectral resolution of modern X-ray instrumentation.…

Solar and Stellar Astrophysics · Physics 2016-07-27 Richard Ignace

Winds are commonly observed in luminous active galactic nuclei (AGNs). A plausible model of those winds is magnetohydrodynamic (MHD) disc winds. In the case of disc winds from a thin accretion disc, isothermal or adiabatic assumption is…

High Energy Astrophysical Phenomena · Physics 2022-06-22 Weixiao Wang , De-Fu Bu , Feng Yuan

Observations of nearby molecular clouds detect "shells", which are likely caused by winds from young main sequence stars. However, the progenitors of these observed features are not well characterized and the mass-loss rates inferred from…

Astrophysics of Galaxies · Physics 2015-10-07 S. S. R. Offner , H. G. Arce

Fast, massive winds are ubiquitously observed in the UV and X-ray spectra of Active Galactic Nuclei (AGN) and other accreting sources. Theoretical and observational evidences suggest they are launched at accretion disc scales, carrying…

High Energy Astrophysical Phenomena · Physics 2024-10-23 Alfredo Luminari , Enrico Piconcelli , Francesco Tombesi , Fabrizio Nicastro , Fabrizio Fiore

We discuss the development of the new radiative transfer code Wind3D. It solves the non-LTE radiative transport problem in moving stellar atmosphere models in three geometric dimensions. The code accepts arbitrary 3D velocity fields in…

Astrophysics · Physics 2007-07-26 A. Lobel , R. Blomme

The standard, or fast, solutions of m-CAK line-driven wind theory cannot account for slowly outflowing disks like the ones that surround Be stars. It has been previously shown that there exists another family of solutions --- the…

Solar and Stellar Astrophysics · Physics 2015-06-23 J. Silaj , M. Cure , C. E. Jones

We present detailed semi-empiric models for rotational modulations observed in ultraviolet wind lines of B0.5 supergiant HD 64760. We model the Rotational Modulation Regions (RMRs) with advanced 3-D radiative transfer calculations in the…

Astrophysics · Physics 2008-09-30 A. Lobel

We present the results of time-dependent hydrodynamic calculations of line- driven winds from accretion disks in AGN. To calculate the radiation force, we take into account radiation from the disk and the central engine. The gas temperature…

Astrophysics · Physics 2009-09-25 D. Proga , J. M. Stone , T. R. Kallman

Small-scale clumping in the winds of hot, massive stars is conventionally included in spectral analyses by assuming optically thin clumps, a void inter-clump medium, and a smooth velocity field. To reconcile investigations of different…

Solar and Stellar Astrophysics · Physics 2015-05-14 J. O. Sundqvist , J. Puls , A. Feldmeier

A number of X-ray binaries exhibit clear evidence for the presence of disk winds in the high/soft state. A promising driving mechanism for these outflows is mass loss driven by the thermal expansion of X-ray heated material in the outer…

High Energy Astrophysical Phenomena · Physics 2017-02-15 Nick Higginbottom , Daniel Proga , Christian Knigge , Knox S. Long

A number of strong infrared forbidden lines have been observed in several evolved Wolf-Rayet star winds, and these are important for deriving metal abundances and testing stellar evolution models. In addition, because these optically thin…

Astrophysics · Physics 2009-11-11 Richard Ignace , Adam Brimeyer

The broad emission lines (BELs) in active galactic nuclei (AGN) respond to ionizing continuum variations. The time and velocity dependence of their response depends on the structure of the broad-line region: its geometry, kinematics and…

Astrophysics of Galaxies · Physics 2017-07-26 S. W. Mangham , C. Knigge , J. H. Matthews , K. S. Long , S. A. Sim , N. Higginbottom

Emission in forbidden lines of oxygen, neon, and other species are commonly used to trace winds from protoplanetary disks. Using Cloudy, we calculate such emission for parametrized wind models of the magnetothermal type, following Bai et…

Solar and Stellar Astrophysics · Physics 2023-11-06 Ahmad Nemer , Jeremy Goodman

Magnetically and thermally driven disk winds have gained popularity in the light of the current paradigm of low viscosities in protoplanetary disks that nevertheless present large accretion rates even in the presence of inner cavities. The…

Earth and Planetary Astrophysics · Physics 2022-03-14 Peter J. Rodenkirch , Cornelis P. Dullemond

The high opacity of He I 10830 makes it an exceptionally sensitive probe of the inner wind geometry of accreting T Tauri stars. In this line blueshifted absorption below the continuum results from simple scattering of stellar photons, a…

Astrophysics · Physics 2008-11-26 John Kwan , Suzan Edwards , William Fischer

Compression of the stellar winds from rapidly rotating hot stars is described by the wind compression model. However, it was also shown that rapid rotation leads to rotational distortion of the stellar surface, resulting in the appearance…

Solar and Stellar Astrophysics · Physics 2014-10-22 Zuzana Cariková , Augustin Skopal