Evidence for a population of beamed radio intermediate quasars

Abstract

Whether radio intermediate quasars possess relativistic jets as radio-loud quasars is an important issue in the understanding of the origin of radio emission in quasars. In this letter, using the two-epoch radio data obtained during Faint Image of Radio Sky at Twenty centimeter sky (FIRST) and NOAO VLA Sky Survey (NVSS), we identify 89 radio variable sources in the Sloan Digital Sky Survey. Among them, more than half are radio intermediate quasars (RL=f2cm/f2500A<250). For all objects with available multiple band radio observations, the radio spectra are either flat or inverted. The brightness temperature inferred from the variability is larger than the synchrotron-self Compton limit for a stationary source in 87 objects, indicating of relativistic beaming. Considering the sample selection and viewing angle effect, we conclude that relativistic jets probably exist in a substantianl fraction of radio intermediate quasars.

arXiv comment15 pages, 4 figures, 1 table, Accepted to the Astrophysical Journal

References in corpus (18)

• Composite Quasar Spectra From the Sloan Digital Sky Survey
• Optical and Radio Properties of Extragalactic Sources Observed by the FIRST and SDSS Surveys
• Black Hole Mass and Eddington Ratio as Drivers for the Observable Properties of Radio-Loud and Radio-Quiet QSOs
• The FIRST Bright Quasar Survey. II. 60 Nights and 1200 Spectra Later
• The VLBA Calibrator Survey - VCS1
• The Sloan Digital Sky Survey Quasar Catalog III. Third Data Release
• Aborted jets and the X-ray emission of radio-quiet AGNs
• The Nature of Radio-Intermediate Quasars: What is Radio-Loud and what is Radio-Quiet?
• VLBA Imaging of Central Engines in Radio Quiet Quasars
• Radio Variability of Radio Quiet and Radio Loud Quasars
• The FIRST Bright QSO Survey
• Is there a Dichotomy in the Radio Loudness Distribution of Quasars?
• Polar Outflows in Six Broad Absorption Line Quasars
• The central engines of radio-quiet quasars
• Double Lobed Radio Quasars from the Sloan Digital Sky Survey
• An Attempt to Probe the Radio Jet Collimation Regions in NGC 4278, NGC 4374 (M84), and NGC 6166
• A relativistic jet in the radio-quiet quasar PG1407+263
• EVN+MERLIN Observations of Radio-Intermediate Quasars: Evidence for Boosted Radio-Weak Quasars

Cited by in corpus (19)

• A Population of Radio-loud Narrow Line Seyfert 1 Galaxies with Blazar-like Properties?
• A narrow line Seyfert 1--blazar composite nucleus in 2MASX J0324+3410
• New Insights on the QSO Radio-Loud/Radio-Quiet Dichotomy: SDSS Spectra in the Context of the 4D Eigenvector1 Parameter Space
• The Radio Properties of Radio-Loud Narrow-Line Seyfert 1 Galaxies on Parsec Scales
• The Radio Properties of Type 2 Quasars
• Investigating kpc-scale radio emission properties of narrow-line Seyfert 1 galaxies
• Constraining the quasar radio-loud fraction at $z\sim 6$ with deep radio observations
• A large sample of Kohonen-selected SDSS quasars with weak emission lines: selection effects and statistical properties
• Intra-Night Optical monitoring of three γ-ray detected Narrow-line Seyfert 1 galaxies
• The central engines of two unusual radio-intermediate/quiet active galactic nuclei: III Zw 2 and PG 1407+265
• G515, Revisited. I. Stellar Populations And Evidence Of Nuclear Activity In A Luminous "E+A" Galaxy
• Gamma-ray Emitting Narrow-Line Seyfert 1 Galaxies: Past, Present, and Future
• Discovery of $\gamma$-ray emission from the radio-intermediate quasar III Zw 2: violent jet activity with intraday $\gamma$-ray variability
• Broad-band spectral energy distribution of 3000 Angstroem break quasars from the Sloan Digital Sky Survey
• Optical variability of radio-intermediate quasars
• The X-ray Spectrum and Spectral Energy Distribution of FIRST J155633.8+351758: a LoBAL Quasar with a Probable Polar Outflow
• On Possibility of Detection of Variable Sources Using the Data of "Cold" Surveys Carried Out on RATAN-600
• Possible gamma-ray emission of radio intermediate AGN III Zw 2 and its implication on the evolution of jets in AGNs
• X-ray galaxies selected from HyperLEDA database