Detection of helicoidal motion in the optical jet of PKS 0521-365
Research output: Contribution to journal › Article › Scientific › peer-review
|Number of pages||5|
|Journal||Monthly Notices of the Royal Astronomical Society|
|Publication status||Published - Sep 2017|
|Publication type||A1 Journal article-refereed|
The jet activity of active galactic nuclei (AGNs), and its interaction with the interstellar medium, may play a pivotal role in the processes that regulate the growth and star formation of its host galaxy. Observational evidence that pinpoints the conditions of such interaction is paramount to unveil the physical processes involved. We report on the discovery of extended emission-line regions exhibiting an S-shaped morphology along the optical jet of the radioloud AGN PKS 0521-365 (z = 0.055), by using long-slit spectroscopic observations obtained with FOcal Reducer/low dispersion Spectrograph 2 on the Very Large Telescope. The velocity pattern derived from the [O II].3727 angstrom, H beta lambda 4861 angstrom and [O III] lambda lambda 4959, 5007 angstrom emission lines is well fitted by a sinusoidal function of the form: v(r) = alpha r(1/2)sin(beta r(1/2) + gamma), suggesting helicoidal motions along the jet up to distances of 20 kpc. We estimate a lower limit for the mass of the outflowing ionized gas along the jet of similar to 10(4)M(circle dot). Helical magnetic fields and jet precession have been proposed to explain helicoidal paths along the jet at pc scales; nevertheless, it is not clear yet whether these hypotheses may hold at kpc scales.
- ISM: jets and outflows, galaxies: active, galaxies: individual: (PKS 0521-365), POWERFUL RADIO GALAXIES, ACTIVE GALACTIC NUCLEI, BL LACERTAE OBJECTS, BRIGHTEST CLUSTER GALAXIES, SPACE-TELESCOPE SURVEY, HOST GALAXIES, ULTRAVIOLET MORPHOLOGY, OBSERVATIONAL EVIDENCE, CLOUD INTERACTIONS, ALMA OBSERVATIONS