Name of the Speaker(s): Maria Marcha
Institution: University of Lisbon
Title of the communication: In Search of Transitional Objects
Preliminary abstract (12 lines max.):
Recent years have seen great productivity in the elaboration of
unified models for Active Galactic Nuclei (AGN). However, there are still
several unanswered questions concerning the relationships between the
different types of AGN. In particular, the ones that concern us here are
those related to the lower luminosity radio-loud objects, often referred
to as Fanaroff \& Riley I galaxies (FR I). Among these fall the BL Lac
objects, an enigmatic type of flat radio spectrum AGN whose peculiar
properties include the generally featureless optical continuum and a
usually high and variable polarisation. Several studies have suggested
that BL Lacs are beamed versions of FR I galaxies. But do all FR I's
hold BL Lac nuclei? Although the present unification schemes establish
broad relationships bewteen different classes of AGN, it is important to
investigate the still existing gaps. One way of doing this is to look
for objects with observational properties that lie somewhere in between
classes. Such is the aim of this communication.