8 research outputs found
The radio luminosity, black hole mass and Eddington ratio for quasars from the Sloan Digital Sky Survey
We investigate the \mbh- \sigma_* relation for radio-loud quasars with
redshift in Data Release 3 of the Sloan Digital Sky Survey (SDSS). The
sample consists of 3772 quasars with better model of H and \oiii lines
and available radio luminosity, including 306 radio-loud quasars, 3466
radio-quiet quasars with measured radio luminosity or upper-limit of radio
luminosity (181 radio-quiet quasars with measured radio luminosity). The virial
supermassive black hole mass (\mbh) is calculated from the broad \hb line, the
host stellar velocity dispersion () is traced by the core \oiii
gaseous velocity dispersion, and the radio luminosity and the radio loudness
are derived from the FIRST catalog. Our results are follows: (1) For
radio-quiet quasars, we confirm that there is no obvious deviation from the
\mbh- \sigma_* relation defined in inactive galaxies when \mbh uncertainties
and luminosity bias are concerned. (2) We find that radio-loud quasars deviate
much from the \mbh- \sigma_* relation respect to that for radio-quiet
quasars. This deviation is only partly due to the possible cosmology evolution
of the \mbh- \sigma_* relation and the luminosity bias. (3) The radio
luminosity is proportional to
\mbh^{1.28^{+0.23}_{-0.16}}(\lb/\ledd)^{1.29^{+0.31}_{-0.24}} for radio-quiet
quasars and \mbh^{3.10^{+0.60}_{-0.70}}(\lb/\ledd)^{4.18^{+1.40}_{-1.10}} for
radio-loud quasars. The weaker correlation of the radio luminosity dependence
upon the mass and the Eddington ratio for radio-loud quasars shows that other
physical effects would account for their radio luminosities, such as the black
hole spin.Comment: 15 pages, 8 figures, 2 tables, accepted for publication in ChJA
Supermassive Black Holes in Galactic Nuclei: Past, Present and Future Research
This review discusses the current status of supermassive black hole research,
as seen from a purely observational standpoint. Since the early '90s, rapid
technological advances, most notably the launch of the Hubble Space Telescope,
the commissioning of the VLBA and improvements in near-infrared speckle imaging
techniques, have not only given us incontrovertible proof of the existence of
supermassive black holes, but have unveiled fundamental connections between the
mass of the central singularity and the global properties of the host galaxy.
It is thanks to these observations that we are now, for the first time, in a
position to understand the origin, evolution and cosmic relevance of these
fascinating objects.Comment: Invited Review, 114 pages. Because of space requirements, this
version contains low resolution figures. The full resolution version can be
downloaded from http://www.physics.rutgers.edu/~lff/publications.htm
Hot gas flows on global and nuclear galactic scales
Since its discovery as an X-ray source with the Einstein Observatory, the hot
X-ray emitting interstellar medium of early-type galaxies has been studied
intensively, with observations of improving quality, and with extensive
modeling by means of numerical simulations. The main features of the hot gas
evolution are outlined here, focussing on the mass and energy input rates, the
relationship between the hot gas flow and the main properties characterizing
its host galaxy, the flow behavior on the nuclear and global galactic scales,
and the sensitivity of the flow to the shape of the stellar mass distribution
and the mean rotation velocity of the stars.Comment: 22 pages. Abbreviated version of chapter 2 of the book "Hot
Interstellar Matter in Elliptical Galaxies", Springer 201