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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

University of Nevada, Las Vegas

2018

Physics & Astronomy Faculty Research

Quasars: General

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Time-Dependent Radiation-Driven Winds, Sergei Dyda, Daniel Proga Oct 2018

Time-Dependent Radiation-Driven Winds, Sergei Dyda, Daniel Proga

Physics & Astronomy Faculty Research

We study temporal variability of radiation-driven winds using one-dimensional, time-dependent simulations and an extension of the classic theory of line-driven winds developed by Castor Abbott & Klein. We drive the wind with a sinusoidally varying radiation field and find that after a relaxation time, determined by the propagation time for waves to move out of the acceleration zone of the wind, the solution settles into a periodic state. Winds driven at frequencies much higher than the dynamical frequency behave like stationary winds with time averaged radiation flux, whereas winds driven at much lower frequencies oscillate between the high and low …


Effects Of Radiation Field Geometry On Line Driven Disc Winds, Sergei Dyda, Daniel Proga Sep 2018

Effects Of Radiation Field Geometry On Line Driven Disc Winds, Sergei Dyda, Daniel Proga

Physics & Astronomy Faculty Research

We study line driven winds for models with different radial intensity profiles: standard Shakura–Sunyaev radiating thin discs, uniform intensity discs, and truncated discs where driving radiation is cut-off at some radius. We find that global outflow properties depend primarily on the total system luminosity but truncated discs can launch outflows with ∼2 times higher mass flux and ∼50 per cent faster outflow velocity than non-truncated discs with the same total radiation flux. Streamlines interior to the truncation radius are largely unaffected and carry the same momentum flux as non-truncated models whereas those far outside the truncation radius effectively carry no …