The Extreme Ultraviolet Deficit and Magnetically Arrested Accretion in Radio Loud Quasars

Abstract

The Hubble Space Telescope composite quasar spectra presented in Telfer et al. show a significant deficit of emission in the extreme ultraviolet (EUV) for the radio loud component of the quasar population (RLQs), compared to the radio quiet component of the quasar population (RQQs). The composite quasar continuum emission between 1100 Å\, and $\sim$580 Å\, is generally considered to be associated with the innermost regions of the accretion flow onto the central black hole. The deficit between 1100 Å\, and 580 Å\, in RLQs has a straightforward interpretation as a missing or a suppressed innermost region of local energy dissipation in the accretion flow. It is proposed that this can be the result of islands of large scale magnetic flux in RLQs that are located close to the central black hole that remove energy from the accretion flow as Poynting flux (sometimes called magnetically arrested accretion). These magnetic islands are natural sites for launching relativistic jets. Based on the Telfer et al. data and the numerical simulations of accretion flows in Penna et al., the magnetic islands are concentrated between the event horizon and an outer boundary of $<2.8M$ (in geometrized units) for rapidly rotating black holes and $<5.5M$ for modestly rotating black holes.

To appear in ApJ Letters

References in corpus (2)

• Magnetically Arrested Disks and Origin of Poynting Jets: Numerical Study
• HST-COS Observations of AGN. II. Extended Survey of Ultraviolet Composite Spectra from 159 Active Galactic Nuclei

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• The Relativistic Jet-Accretion Flow-Wind Connection in Mrk\,231
• The Extreme Ultraviolet Variability of Quasars
• Estimating the Jet Power of Mrk\,231 During the 2017-2018 Flare
• Constraining X-ray emission of magnetically arrested disk (MAD) by radio-loud AGNs with extreme ultraviolet (EUV) deficit