Astronomy and Astrophysics – Astronomy
Scientific paper
May 1997
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997aas...190.3911s&link_type=abstract
American Astronomical Society, 190th AAS Meeting, #39.11; Bulletin of the American Astronomical Society, Vol. 29, p.830
Astronomy and Astrophysics
Astronomy
Scientific paper
HST observations of some QSOs show a strong, abrupt increase in polarization at rest wavelength about 750 Angstroms (Impey et al. 1995, Ap.J. 440, 80; Koratkar et al. 1995, Ap.J. 450, 501). The polarization rises from 1 to 2% at longer wavelengths to values as high as 20% at the shortest observed wavelengths. The closeness of the polarization rise to the H I Lyman edge suggests a connection, but the displacement to shorter wavelengths, and the shape of the polarization rise require explanation. We have computed the polarized spectrum of a thermally emitting accretion disk around a supermassive black hole, including the effects of the relativistic transfer function (Laor et al. 1990, MNRAS 242, 560). We achieve a good fit to the observed polarization rise in a model in which the locally emitted radiation at the disk surface is assumed to have a sharp increase in polarized flux at the Lyman edge in the rest frame of the gas. Relativistic effects cause the observed polarization to rise fairly sharply at a wavelength substantially less than 912 Angstroms. The blueshift depends on the radius at which the bulk of the polarized Lyman continuum is emitted, which in turn depends on the angular momentum of the black hole. A dimensionless angular momentum a = 0.5 agrees with the observed polarization feature in PG 1630+377. An intermediate value of black hole angular momentum might result from successive accretion events involving material orbiting in different planes. This material is based in part upon work supported by the Texas Advanced Research Program under Grant No. 003658-015.
Husfeld Dirk
Shields Gregory A.
Wobus Lance
No associations
LandOfFree
Lyman Continuum Polarization in QSOs: Evidence for a Moderately Rotating Black Hole? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Lyman Continuum Polarization in QSOs: Evidence for a Moderately Rotating Black Hole?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lyman Continuum Polarization in QSOs: Evidence for a Moderately Rotating Black Hole? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-831431