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Evidence for Radiative Acceleration in Quasars

Published online by Cambridge University Press:  12 April 2016

Nahum Arav*
Affiliation:
Theoretical Astrophysics, Caltech 130–33, Pasadena, California 91125, USA

Abstract

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I give an overview of a promising signature for radiative acceleration in quasars “the ghost of Lyα,” which is seen in the spectra of a few broad absorption line (BAL) QSOs. The ghost appears as an absorption hump in the C IV λ1549 BAL and is centered around 5,900 km s−1 to the blue of the corresponding broad emission line (BEL). This velocity separation is the same as the velocity separation between the N V λ1240 and Lyα lines. Thus, when the N V BAL and the C IV BAL are plotted as a function of velocity (where zero velocity corresponds to the peaks of these BELs), the hump in the C IV BAL appears at the same velocity as the Lyα BEL and qualitatively resembles it. The best examples and model fits are shown and the radiative dynamics explained.

Type
Part 12. Outflows from YSO and AGN
Copyright
Copyright © Astronomical Society of the Pacific 1997

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