Astronomy and Astrophysics – Astronomy
Scientific paper
Dec 1987
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1987phdt........47e&link_type=abstract
Thesis (Ph.D.) -- California Institute of Technology, 1987. Advisor(s): Schmidt, Maarten (advisor); Moffet, Alan Theodore (advis
Astronomy and Astrophysics
Astronomy
Astronomy
Scientific paper
The broadband radio-infrared-optical-ultraviolet properties of active galactic nuclei are used to investigate the nature of the central engine and the surrounding environment. Optically selected quasars (which have [...] = [...]) and Seyfert 1 galaxies ([...] = [...]) tend to have relatively flat infrared spectra and low reddenings, while most Seyfert 2 galaxies ([...] = [...]) and other dusty objects have steep infrared spectra and larger reddenings. The infrared spectra of most luminous radio-quiet active galaxies turn over near [...]80 [...]. It appears that the infrared spectra of most quasars and luminous Seyfert 1 galaxies are dominated by unreprocessed radiation from a synchrotron self-absorbed source of order a light day across, about the size of the hypothesized accretion disk. Seyfert 2 galaxies and other reddened objects have infrared spectra which appear to be dominated by thermal emission from warm ([...]50 K) dust, probably in the disk of the underlying galaxy. A broad emission feature, centered near 5 [...], is present in many luminous quasars and Seyfert 1 galaxies.Highly polarized objects ("blazars") can be strongly variable at far-infrared wavelengths over time scales of months. There is no conclusive evidence for far-infrared variations in normal (low-polarization) quasars or Seyfert galaxies, although low-level flickering (at the [...]30% peak-to-peak level) cannot be ruled out.Seyfert galaxies tend to have steep radio spectra ([...]). The radio spectra of Seyfert 1 galaxies often flatten out near 2 cm. There is no significant difference in the mean radio luminosities of Seyfert 1 and 2 galaxies. There are of order 10[...] Seyfert galaxies/Gpc[...], most of which have 6 cm luminosities between 10[...] and 10[...] ergs/s and 60 [...] luminosities between 10[...] and 10[...] ergs/s. The Seyfert 2 galaxy radio luminosity function cuts off sharply below 10[...] ergs/s.
No associations
LandOfFree
Broadband properties of active galactic nuclei 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 Broadband properties of active galactic nuclei, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Broadband properties of active galactic nuclei will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-905947