Subrelativistic jets from black hole accretion vortices. I. The extreme-ultraviolet and X-ray emission from radio-quiet quasars

Authors
Citation
B. Punsly, Subrelativistic jets from black hole accretion vortices. I. The extreme-ultraviolet and X-ray emission from radio-quiet quasars, ASTROPHYS J, 527(2), 1999, pp. 609-623
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004-637X → ACNP
Volume
527
Issue
2
Year of publication
1999
Part
1
Pages
609 - 623
Database
ISI
SICI code
0004-637X(199912)527:2<609:SJFBHA>2.0.ZU;2-7
Abstract
This article and its companion describe a theory of quasars that differenti ates radio-loud quasars from radio-quiet quasars by the physical structures extant in the accretion vortices above the poles of a supermassive, rapidl y rotating black hole. Quasars are manifestly radio loud as a consequence o f large-scale magnetic flux threading these funnels and relativistic magnet ic winds of plasma that propagate outward (magnetic wind models of radio-lo ud quasars exist in the literature). Radio-quiet quasars are devoid of this large-scale magnetic flux, and radiation pressure in the funnel drives hyp ersonic, underexpanded, subrelativistic jets. These jets are relatively fee ble compared to the radiation-driven relativistic jets from the funnels of superluminous accretion disks that were popular in the theoretical literatu re of the 1980s. The primary emphases of this article are the near-field dy namics and the observational implications of the radiation-driven jets from these vortices conjectured to exist in radio-quiet quasars. The physical s tate of the ejecta is governed by the force of gravity, the initiating cont inuum radiation pressure, and the line-driving forces from ultraviolet accr etion disk radiation. These hypersonic jets form a bipolar broad absorption line region (BALR) with a small covering factor dictated by the collimatio n of the jets. Consequently, radio-quiet quasars have broad absorption line s in the UV region of their spectra if the line of sight passes through a j et. Radio-loud quasars do not have BALRs in this model. It is demonstrated in the companion article that absorbing columns with a range of outflow vel ocities from approximate to 0 km s(-1) to more than 35,000 km s(-1) result in these putative jets. In this article it is shown that the frictional and compressional heating in the turbulent boundary layer between the base of the jet and the funnel walls creates a hot corona above the innermost regio ns of the disk. The corona cools by Compton-scattering disk UV radiation, c reating the far-UV and soft X-ray excess that radio-quiet quasars have rela tive to radio-loud quasars as found in composite spectra of the Hubble Spac e Telescope (HST) and ROSAT archives, respectively. Furthermore, Compton co oling of the hot outer regions of the corona creates the flat spectral ener gy distribution of hard X-rays observed in radio-quiet quasars. By the geom etry of an X-ray source collaring the base of the jet, if the line of sight passes through the jet (a BAL quasar), X-ray emission is obscured. Thus, s oft X-ray emission is suppressed in BAL quasars relative to the rest of the radio-quiet population in the model as observed. Seyfert galaxies do not h ave disks that are luminous to drive winds from the vortex and hence do not have BALRs in the model consistent with IUE searches.