Title: The UV excess of quasars - Luminosity dependence
Abstract: view Abstract Citations (15) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The UV Excess of Quasars: Luminosity Dependence Wandel, Amri Abstract The transition from the near-infrared power law to the blue bump in quasar spectra is studied by analyzing the complete sample published by Neugebauer et al. (1987). It is found that the flattening of the continuum spectrum toward the UV increases with continuum luminosity; the spectral slope between 4200 A and 7500 A (in the quasar's rest frame) is strongly correlated with luminosity and redshift. Only part of this correlation can be attributed to contamination by starlight of the host galaxy. This result is modeled in terms of an accretion disk spectrum combined with a nonthermal power law. In order to fit the data, the Eddington ratio must be in the range L(opt)/L(E) approximately 0.003-0.03(epsilon/0.1) exp -1 (epsilon being the efficiency). This parameter range also yields inner disk temperatures of (30,000-200,000 K), in accordance with the temperatures inferred from the UV excess of quasars observed with the IUE. Publication: The Astrophysical Journal Pub Date: May 1987 DOI: 10.1086/184891 Bibcode: 1987ApJ...316L..55W Keywords: Galactic Nuclei; Luminous Intensity; Quasars; Radiation Spectra; Ultraviolet Radiation; Balmer Series; Black Body Radiation; Infrared Radiation; Astrophysics; QUASARS; ULTRAVIOLET: SPECTRA full text sources ADS | data products MAST (1)