Letter to the Editor

Superluminal non-ballistic jet swing in the quasar NRAO 150 revealed by mm-VLBI^*

¹ Instituto de Astrofísica de Andalucía (CSIC), Apartado 3004, 18080 Granada, Spain e-mail: iagudo@iaa.es
² Max-Planck-Institut für Radioastronomie, Auf dem Hügel, 69, 53121, Bonn, Germany
³ Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215, USA
⁴ National and Kapodestrian University of Athens, Dept. of Astrophysics, Astronomy and Mechanics, 157 83 Athens, Greece
⁵ University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL, UK
⁶ Institut de RadioAstronomie Millimétrique, 300 rue de la Piscine, 38406 Saint Martin d'Hères, France
⁷ Instituto de Astrofísica de Canarias, C/Vía Láctea s/n, 38200, La Laguna, Tenerife, Spain

Received: 8 August 2007
Accepted: 24 October 2007

Abstract

Context.NRAO 150, a compact and bright radio to mm source showing core/jet structure, has been recently identified as a quasar at redshift through a near-IR spectral observation.

Aims.To study the jet kinematics on the smallest accessible scales and to compute the first estimates of its basic physical properties.

Methods.We have analysed the ultra-high-resolution images from a new monitoring program at 86 GHz and 43 GHz with the Global mm VLBI Array and the VLBA, respectively. An additional archival calibration VLBA data set, covering the period from 1997 to 2007, has been used.

Results.Our data show an extreme projected counter-clockwise jet position angle swing at an angular rate of up to ≈11° yr within the inner 3 pc of the jet, which is associated with a non-ballistic superluminal motion of the jet within this region.

Conclusions.The results suggest that the magnetic field could play an important role in the dynamics of the jet in NRAO 150, which is supported by the large values of the magnetic field strength obtained from our first estimates. The extreme characteristics of the jet swing make NRAO 150 a prime source to study the jet wobbling phenomenon.