Refereed journal article or data article (A1)

MOJAVE. XVII. Jet Kinematics and Parent Population Properties of Relativistically Beamed Radio-loud Blazars




List of AuthorsLister ML, Homan DC, Hovatta T, Kellermann KI, Kiehlmann S, Kovalev YY, Max-Moerbeck W, Pushkarev AB, Readhead ACS, Ros E, Savolainen T

PublisherIOP PUBLISHING LTD

Publication year2019

JournalAstrophysical Journal

Journal name in sourceASTROPHYSICAL JOURNAL

Journal acronymASTROPHYS J

Article numberARTN 43

Volume number874

Issue number1

Number of pages19

ISSN0004-637X

eISSN0004-637X

DOIhttp://dx.doi.org/10.3847/1538-4357/ab08ee


Abstract
We present results from a parsec-scale jet kinematics study of 409 bright radio-loud active galactic nuclei (AGNs) based on 15 GHz Very Long Baseline Array (VLBA) data obtained between 1994 August 31 and 2016 December 26 as part of the 2 cm VLBA survey and Monitoring Of Jets in Active galactic nuclei with VLBA Experiments (MOJAVE) programs. We tracked 1744 individual bright features in 382 jets over at least 5 epochs. A majority (59%) of the best-sampled jet features showed evidence of accelerated motion at the >3 sigma level. Although most features within a jet typically have speeds within similar to 40% of a characteristic median value, we identified 55 features in 42 jets that had unusually slow pattern speeds, nearly all of which lie within 4 pc (100 pc deprojected) of the core feature. Our results, combined with other speeds from the literature, indicate a strong correlation between apparent jet speed and synchrotron peak frequency, with the highest jet speeds being found only in low-peaked AGNs. Using Monte Carlo simulations, we find best-fit parent population parameters for a complete sample of 174 quasars above 1.5 Jy at 15 GHz. Acceptable fits are found with a jet population that has a simple unbeamed power-law luminosity function incorporating pure luminosity evolution and a power-law Lorentz factor distribution ranging from 1.25 to 50 with slope -1.4 +/- 0.2. The parent jets of the brightest radio quasars have a space density of 261 +/- 19 Gpc(-3) and unbeamed 15 GHz luminosities above similar to 10(24.5) W Hz(-1), consistent with FR II class radio galaxies.


Last updated on 2021-24-06 at 08:27