We make a case for the existence for ultra-massive black holes (UMBHs) in the Universe, but argue that there exists a likely upper limit to black hole masses of the order of M ∼ 1010M⊙. We show that there are three strong lines of argument that predicate the existence of UMBHs: (i) expected as a natural extension of the observed black hole mass bulge luminosity relation, when extrapolated to th...

Virial black-hole mass estimates are presented for 12698 quasars in the redshift interval 0.1 ≤ z ≤ 2.1, based on modelling of spectra from the Sloan Digital Sky Survey (SDSS) first data release . The black-hole masses of the SDSS quasars are found to lie between ≃ 10 M⊙ and an upper limit of ≃ 3 × 10 9 M⊙, entirely consistent with the largest black-hole masses found to date in the local Univer...

The recently suggested interpretation [1] of the universal hadronic freeze-out temperature T f (≃ 170 Mev) – found for all high energy scattering processes that produce hadrons: e + e − , pp, p¯ p, πp, etc. and N N ′ (heavy-ion collisions) – as a Unruh temperature triggers here the search for the gravitational black-hole that in its near-horizon approximation better simulates this hadronic phen...

New virial black-hole mass estimates are presented for a sample of 72 AGN covering three decades in optical luminosity. Using a model in which the AGN broad-line region (BLR) has a flattened geometry, we investigate the M bh − L bulge relation for a combined 90-object sample, consisting of the AGN plus a sample of 18 nearby inactive elliptical galaxies with dynamical black-hole mass measurement...

The hole drilling method is one of the most used semi-destructive techniques for residual stress analysis of mechanical parts. In the presence of non-uniform residual stresses, the stress field can be determined from the measured relaxed strains using several methods, but the most used is the so called integral method. This method is characterized by some simplifications that lead to approximat...

We investigate the relationship between black hole mass and host galaxy properties for active galaxies with the lowest black hole masses currently known in galaxy nuclei. Hubble Space Telescope imaging confirms that the host galaxies have correspondingly low luminosity; they are ∼ 1 mag below L. In terms of morphology, ∼ 60% of the sample are disk-dominated, and all of these are consistent with...

New black-hole mass estimates are presented for a sample of 72 AGN covering three decades in optical luminosity. Using a sub-sample of Seyfert galaxies, which have blackhole mass estimates from both reverberation mapping and stellar velocity dispersions, we investigate the geometry of the AGN broad-line region (BLR). It is demonstrated that a model in which the orbits of the line-emitting mater...