Host galaxies and black hole masses of low and high luminosity radio loud active nuclei

Renato Falomo; Nicoletta Carangelo; Aldo Treves

doi:10.1046/j.1365-8711.2003.06690.x

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Host galaxies and black hole masses of low and high luminosity radio loud active nuclei

Renato Falomo·Nicoletta Carangelo·Aldo Treves

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Abstract

We investigate the host galaxy luminosities of BL Lac Objects (BLLs) and Radio Loud Quasars (RLQs) at z<0.5 imaged with the Hubble Space Telescope (HST). From a homogeneous treatment of the data we construct the host galaxy luminosity functions (HGLFs) and find that RLQ hosts are ~0.5 mag brighter than those of BLL: _BLL= -23.5. For both classes the HGLFs exhibit a remarkably different distribution with respect to that of normal (inactive) ellipticals, with clear preference for more luminous galaxies to show nuclear activity. We make use of the black hole mass -- bulge luminosity (M[BH] -L[bulge]) relation, derived for nearby inactive ellipticals, to estimate the central black hole mass in our sample of radio loud active galaxies. In spite of a ~2 order of magnitude difference of intrinsic nuclear luminosity BLL and RLQ have BH of similar mass _BLL= 5.6x10^{8}, <M[BH]/M[sun]_RLQ = 1.0 10^{9}). This implies that the two types of objects are radiating at very different rates with respect to their Eddington luminosity.

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Renato Falomo, Nicoletta Carangelo, Aldo Treves. 2003-04-10. Host galaxies and black hole masses of low and high luminosity radio loud active nuclei. https://doi.org/10.1046/j.1365-8711.2003.06690.x

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