6533b858fe1ef96bd12b5b59
RESEARCH PRODUCT
Absolute kinematics of radio-source components in the complete S5 polar cap sample: IV. Proper motions of the radio cores over a decade and spectral properties
Ivan Marti-vidalF. J. AbellanJ. M. MarcaideMiguel A. Pérez-torresJ. C. GuiradoEduardo RosEduardo Rossubject
AstrofísicaActive galactic nucleusAstrometriaAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysicsKinematics01 natural sciencesStability (probability)Radio continuum: generalBinary black hole0103 physical sciencesVery-long-baseline interferometry010306 general physicsInstrumentation and Methods for Astrophysics (astro-ph.IM)010303 astronomy & astrophysicsAstrophysics::Galaxy AstrophysicsPhysicsJet (fluid)general [Radio continuum]general [BL Lacertae objects]Astrophysics::Instrumentation and Methods for AstrophysicsAstronomy and Astrophysicsgeneral [Quasars]BL Lacertae objects: generalAstrometryAstrometryAstrophysics - Astrophysics of GalaxiesQuasars: generalGravitational lensSpace and Planetary ScienceAstrophysics of Galaxies (astro-ph.GA)Techniques: interferometricinterferometric [Techniques]Astrophysics - Instrumentation and Methods for Astrophysicsdescription
We have carried out a high-precision astrometric analysis of two very-long-baseline-interferometry (VLBI) epochs of observation of the 13 extragalactic radio sources in the complete S5 polar cap sample. The VLBI epochs span a time baseline of ten years and enable us to achieve precisions in the proper motions of the source cores up to a few micro-arcseconds per year. The observations were performed at 14.4 GHz and 43.1 GHz, and enable us to estimate the frequency core-shifts in a subset of sources, for which the spectral-index distributions can be computed. We study the source-position stability by analysing the changes in the relative positions of fiducial source points (the jet cores) over a decade. We find motions of 0.1-0.9 mas among close-by sources between the two epochs, which imply drifts in the jet cores of approximately a few tens of μas per year. These results have implications for the standard Active Galactic Nucleus (AGN) jet model (where the core locations are supposed to be stable in time). For one of our sources, 0615+820, the morphological and spectral properties in year 2010, as well as the relative astrometry between years 2000 and 2010, suggest the possibility of either a strong parsec-scale interaction of the AGN jet with the ISM, a gravitational lens with ~1 mas diameter, or a resolved massive binary black hole. © ESO, 2016.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-07-18 |