Ionization Driven Fragmentation of Gas Outflows Responsible for FeLoBALs in Quasars - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




Ionization Driven Fragmentation of Gas Outflows Responsible for FeLoBALs in Quasars - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We show that time variations in the UV ionizing continuum of quasars, onscales of $\sim$1 year, affect the dynamic structure of the plasmas responsiblefor low ionization broad absorption lines. Variations of the ionizing continuumproduce non-equilibrium photoionization conditions over a significant fractionof the absorbing clouds and supersonically moving ionization fronts. When theflux drops the contraction of the ionized region drives a supersonic coolingfront towards the radiation source and a rarefaction wave in the oppositedirection. The pressure imbalance is compensated by an increased speed of thecool gas relative to the front. When the flux recovers the cool gas isre-ionized and re-heated by a supersonic ionization front traveling away fromthe radiation source and a forward shock is created. The reheated cloudsequilibrate to a temperature of $\sim 10^4$ K and are observed to havedifferent radial velocities than the main cloud. Such fragmentation seemsconsistent with the multicomponent structure of troughs seen in some objects.The velocity differences measured among various components in the quasars QSO2359-1241 and SDSS J0318-0600 can be reproduced by our model if strongmagnetic fields $\sim$10 mG are present within the clouds.



Author: Manuel A. Bautista, Jay P. Dunn

Source: https://arxiv.org/







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