Tampere University of Technology

TUTCRIS Research Portal

Detection of helicoidal motion in the optical jet of PKS 0521-365

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Pages (from-to)L107-L111
Number of pages5
JournalMonthly Notices of the Royal Astronomical Society
Volume470
Issue number1
DOIs
Publication statusPublished - Sep 2017
Publication typeA1 Journal article-refereed

Abstract

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.

Keywords

  • 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

Publication forum classification

Field of science, Statistics Finland