The two-stage origin of bright rings in extended radio lobes

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

8

Hydrodynamics, Galaxies: Jets, Radio Continuum: Galaxies

Scientific paper

A few strong radio sources show unusual large-intensity features (up to 100- or 200-kpc scale) within their extended lobes. These appear in the plane of the sky as nearly circular rings, but physically they are actually spherical shells. Two such sources, HerA (3C348) and 3C310, are analysed in terms of their similarly uniform kinematics. Such objects do not easily fit into the Fanaroff-Riley scheme for jet and lobe sources. We model these sources by a two-stage account of their dynamics. Long ago, acoustic waves (or weak shocks) were excited again and again to form sphere after sphere in the pre-existing thermal galactic wind. They all arose at one spot along the jet axis at the edge of the galaxy, to drift with the wind, expanding uniformly at the speed of sound in the near-isothermal gas. The wind flows out supersonically at about Mach 5. In a much later second stage, a new and much faster flow of relativistic plasma is energized by the active nucleus deep within the galaxy. That plasma jet swiftly forms the radio lobe and infuses it with radio electrons. The new plasma fills in locally the low-pressure portions of each drifting acoustic shell. The shells then appear as a procession of radio rings, with modest intensity contrast and an understandable polarization. Both of these radio ring sources appear to have optically double active nuclei. Perhaps periodic tidal forces determine the density modulations during the older outflow that gave rise to the several drifting shells.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The two-stage origin of bright rings in extended radio lobes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The two-stage origin of bright rings in extended radio lobes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The two-stage origin of bright rings in extended radio lobes will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1126380

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.