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.