EAS Publications Series
Volume 10, 2003JENAM 2002, Galactic & Stellar Dynamics
|Page(s)||211 - 211|
|Published online||22 December 2003|
C. Boily, P. Patsis, S. Portegies Zwart, R. Spurzem and C. Theis (eds)
EAS Publications Series, 10 (2003) 211
Spectroscopic study of low luminosity BL Lac type objects
CAAUL, Observatório Astronómico
de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal
2 ESO, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany
We have examined the spectroscopic properties of a sample of 19 optically bright, low luminosity core-dominated radio sources; this sample was expected to contain a high fraction of objects observed at small angles to the line-of-sight (blazar-like objects). Our study focuses on the properties - stellar populations and optical emission-line spectra - of such nuclei. Stellar population synthesis shows that their nuclear populations are composed, in a general way, of old stars of solar metallicity or lower; the dust content is weak. After subtraction of the stellar contribution, we are left with a set of nuclear emission-line spectra; their analysis shows that most of the objects harbour a Low Ionisation Nuclear Emission Region (or LINER), whose contribution was highly diluted by the host galaxy starlight. Such a low ionisation spectrum is in agreement with the black hole mass values and sub-Eddington accretion rates published for some BL Lacs; also, the stellar populations derived in this study are in agreement with those usually found in LINERs. Our findings give strength to a unifying picture involving low luminosity blazar-like objects and FR I radio-galaxies (which usually display LINER-type spectra).
© EAS, EDP Sciences, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.