Back to Volume
Paper: The Co-existence of BL Lacs and Broad Lines
Volume: 159, BL Lac Phenomenon
Page: 20
Authors: Marchã, M.
Abstract: Historically, BL Lac objects are flat radio spectrum sources that do not show strong emission features in their spectrum. This feature, along with other radio properties, contributed to the suggestion that BL Lacs are really the cores of low luminosity radio galaxies (FRI type) but which are viewed along the direction of the radio jet emission. Such 'unification' of BL Lac objects and FRI galaxies has by now established itself as the existing scheme for low luminosity radio sources. However, recent observations have not only shown that the prototype of BL Lacs has broad emission lines, but also that as we select weaker radio sources, the separation between objects with broad and narrow emission lines becomes less clear. By studying a new sample of low luminosity, flat radio sources, we investigate whether the host galaxies and close environments are a determinant factor in this behaviour.
Back to Volume