| Type |
Journal Article |
| Names |
Sarka Wykes, Huib T. Intema, Martin J. Hardcastle, Abraham Achterberg, Thomas W. Jones, Helmut Jerjen, Emanuela Orrú, Alex Lazarian, Timothy W. Shimwell, Michael W. Wise, Philipp P. Kronberg |
| Publication |
Monthly Notices of the Royal Astronomical Society |
| Volume |
442 |
| Issue |
4 |
| Pages |
2867-2882 |
| Journal Abbreviation |
Monthly Notices of the Royal Astronomical Society |
| Date |
August 1, 2014 |
| DOI |
10.1093/mnras/stu1033 |
| ISSN |
0035-8711 |
| Short Title |
Filaments in the southern giant lobe of Centaurus A |
| URL |
http://adsabs.org/2014MNRAS.442.2867W |
| Library Catalog |
adslabs.org |
| Abstract |
We present results from imaging of the radio filaments in the southern
giant lobe of Centaurus A using data from Giant Metrewave Radio
Telescope observations at 325 and 235 MHz, and outcomes from filament
modelling. The observations reveal a rich filamentary structure, largely
matching the morphology at 1.4 GHz. We find no clear connection of the
filaments to the jet. We seek to constrain the nature and origin of the
vertex and vortex filaments associated with the lobe and their role in
high-energy particle acceleration. We deduce that these filaments are at
most mildly overpressured with respect to the global lobe plasma showing
no evidence of large-scale efficient Fermi I-type particle acceleration,
and persist for ˜2-3 Myr. We demonstrate that the dwarf galaxy KK
196 (AM 1318-444) cannot account for the features, and that surface
plasma instabilities, the internal sausage mode and radiative
instabilities are highly unlikely. An internal tearing instability and
the kink mode are allowed within the observational and growth time
constraints and could develop in parallel on different physical scales.
We interpret the origin of the vertex and vortex filaments in terms of
weak shocks from transonic magnetohydrodynamical turbulence or from a
moderately recent jet activity of the parent AGN, or an interplay of
both. |
| Tags |
Instabilities, TECHNIQUES: IMAGE PROCESSING, galaxies: individual (Centaurus A), galaxies: jets, radio continuum: galaxies, turbulence |