Nuclear Structure, Obscuration and Host Galaxies of the Youngest Radio Galaxies

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

One of the most enduring and difficult mysteries concerning radio galaxies is the conditions which trigger the onset of the active phase. We have investigated these mysteries by observing with HST three nearby (z < 0.1) compact symmetric objects, radio sources whose physical sizes ( 100-1000 pc) and lobe advance speeds indicate that their active phase and ejection of radio lobes began 103-10^4 years ago. Our target objects, 4C 31.04, 1946+708 and 1146+596 (=NGC 3894), were chosen for HST observations both on the basis of proximity as well as detected HI line emission. All three objects are well fit by ``nuker" models typical of nearby ellipticals. They also appear to be in moderately rich environments, with each having a companion within 20-70 kpc projected distance. However, the galaxies are much dustier (by a full order of magnitude) than typical bright, L* ellipticals. The dust features we see include nuclear disks or tori in all three, with apparent geometries consistent with a perpendicular orientation to the radio axis. One galaxy, 4C 31.04, exhibits bright nuclear regions well aligned with the radio axis, while another, 1146+596, shows a significant near-IR excess along its dust disk. We discuss the physical conditions in the dust disk and nucleus, and the possible association of the nuclear obscuration with the radio lobes and the onset of activity in these objects. The lack of observed isophotal anomalies in these objects has important implications for the scenario proposed by Wilson & Colbert, whereby radio-loud AGN are triggered by major mergers of two (possibly active) spiral galaxies: in particular, any such mergers must have happened at least ~ 108 years ago (the crossing time for the product galaxies).

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

Nuclear Structure, Obscuration and Host Galaxies of the Youngest Radio Galaxies 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 Nuclear Structure, Obscuration and Host Galaxies of the Youngest Radio Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nuclear Structure, Obscuration and Host Galaxies of the Youngest Radio Galaxies will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1727832

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