The NIR to UV continuum of radio loud vs. radio quiet quasars

Abstract

Starting from a sample of SDSS quasars appearing also in the 2MASS survey, we study the continuum properties of about 1000 objects observed in 8 bands, from NIR to UV. We construct the mean spectral energy distribution (SED) and compare and contrast the continua of radio loud (RLQ) and radio quiet (RQQ) objects. The SEDs of the two populations are significantly different in the sense that RLQs are redder, with power law spectral indices <alpha(RLQ)>=-0.55+/-0.04 and <alpha(RQQ)>=-0.31+/-0.01 in the spectral range between 10^14.5 and 10^15.35 Hz. This difference is discussed in terms of different extinctions, different disc temperatures, or slopes of the non-thermal component.

7 pages, 6 figures. To appear in MNRAS

References in corpus (3)

• The Radio-Loud Fraction of Quasars is a Strong Function of Redshift and Optical Luminosity
• Signals from the Noise: Image Stacking for Quasars in the FIRST Survey
• The BH mass of nearby QSOs: a comparison of the bulge luminosity and virial methods

Cited by in corpus (5)

• New Insights on the QSO Radio-Loud/Radio-Quiet Dichotomy: SDSS Spectra in the Context of the 4D Eigenvector1 Parameter Space
• Evidence for higher black hole spin in radio-loud quasars
• An Apparent Redshift Dependence of Quasar Continuum: Implication for Cosmic Dust Extinction?
• Polarization of broad line emission from AGNs with determined virial factors
• Probing the rapid formation of black holes and their galaxy hosts in QSOs