NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-03-21 T08:57:17 PDT
Help | Comment | NED Home

For refcode 1996AJ....111...53O:
Retrieve 339 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
1996AJ....111...53O OPTICAL SPECTROSCOPY OF RADIO GALAXIES IN ABELL CLUSTERS II. BL LACS AND FR I UNIFICATION FRAZER N. OWEN AND MICHAEL J. LEDLOW National Radio Astronomy Observatory4, Socorro, New Mexico 87801 Electronic mail: fowen@aoc.nrao.edu, mledlow@nmsu.edu WILLIAM C. KEEL Department of Physics and Astronomy. University of Alabama, Tuscaloosa, Alabama 35487 Electronic mail: kecl@bildad.astr.ua.edu Received 1995 July 29; revised 1995 October 10 ABSTRACT As part of our optical spectroscopic study of radio galaxies in Abell clusters, we report a search for BL Lac phenomena in our sample. As an indicator of possible nonthermal activity in the nuclei of our radio galaxies, we report D(4000), a measure of the 4000 A break, for 190 objects. None of the objects in our sample are found which meet the tions for BL Lac objects both for D(4000) and for weakness of emission lines. We do find 15 objects which have diluted 4000 A breaks [D(4000)<= 1.8], and these are discussed individually. At least four of them appear to have weak nonthermal activity which may be related to the BL Lac phenomena. These results appear to be in conflict with the simplest BL Lac/FR I unification model. Several ways out of this dilemma are discussed. Perhaps the most likely change in this model is the inclusion of FR II radio galaxies as part of the parent population of BL Lac objects. ========================================================================
Retrieve 339 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home