Central Velocity Dispersion Research Articles

Discussing the first velocity dispersion profile of an ultra-diffuse galaxy in MOND

Using Jeans modeling, we calculated the velocity dispersion profile of the ultra-diffuse galaxy (UDG) Dragonfly 44 in MOND. For the nominal mass-to-light ratio from the literature and an isotropic profile, the agreement with the data is excellent near the center of the galaxy. However, in modified gravity, close to the cluster core, the gravitational environment should bring the galaxy back toward Newtonian behavior. The success of the isolated MOND prediction for the central velocity dispersion could then mean that the galaxy is at a great distance (≫5 Mpc) from the cluster core, as hinted by the fact that nearby UDGs share similar velocities with a dispersion well below that of the cluster itself. There is, however, a 2σ tension in the outer part of the UDG due to an increase in the observed dispersion profile with respect to the flat MOND prediction. This deviation could simply be a measurement error. Other possibilities could be, for a UDG far from the cluster, a higher-than-nominal baryonic mass with a tangentially anisotropic dispersion profile or it could even be a dark baryonic halo. If the UDG is closer to the cluster core, the deviation could be a sign that it is in the process of disruption.

The kinematics of star clusters undergoing gas expulsion in Newtonian and Milgromian dynamics

We study the kinematics of stars in clusters undergoing gas expulsion in standard Newtonian dynamics and also in Milgromian dynamics (MOND). Gas expulsion can explain the observed line-of-sight (LoS) velocity dispersion profile of NGC 2419 in Newtonian dynamics. For a given star formation efficiency (SFE), the shapes of the velocity dispersion profiles, which are normalised by the velocity dispersion at the projected half-mass radius, are almost indistinguishable for different SFE models in Newtonian dynamics. The velocity dispersion of a star cluster in the outer halo of a galaxy can indeed have a strong radial anisotropy in Newtonian dynamics after gas expulsion. MOND displays several different properties from Newtonian dynamics. In particular, the slope of the central velocity dispersion profile is less steep in MOND for the same SFE. Moreover, for a given SFE, more massive embedded cluster models result in more rapidly declining central velocity dispersion profiles for the final star clusters, while less massive embedded cluster models lead to flatter velocity dispersion profiles for the final products. The onset of the radial-orbit instability in post-gas-expulsion MOND models is discussed. SFEs as low as a few percent, typical of molecular clouds, lead to surviving ultra-diffuse objects. Gas expulsion alone is unlikely the physical mechanism for the observed velocity dispersion profile of NGC 2419 in MOND.

A Consistent Set of Empirical Scaling Relations for Spiral Galaxies: The (vmax, MoM)–(σ0, MBH, ϕ) Relations

Abstract Using the latest sample of 48 spiral galaxies having a directly measured supermassive black hole mass, M BH, we determine how the maximum disk rotational velocity, v max (and the implied dark matter halo mass, M DM), correlates with the (i) black hole mass, (ii) central velocity dispersion, σ 0, and (iii) spiral-arm pitch angle, ϕ. We find that M BH ∝ v max 10.62 ± 1.37 ∝ M DM 4.35 ± 0.66 , significantly steeper than previously reported, and with a total root mean square scatter (0.58 dex) similar to that about the M BH–σ 0 relation for spiral galaxies—in stark disagreement with claims that M BH does not correlate with disks. Moreover, this M BH–v max relation is consistent with the unification of the Tully–Fisher relation (involving the total stellar mass, M *,tot) and the steep M BH ∝ M * , tot 3.05 ± 0.53 relation observed in spiral galaxies. We also find that σ 0 ∝ v max 1.55 ± 0.25 ∝ M DM 0.63 ± 0.11 , consistent with past studies connecting stellar bulges (with σ 0 ≳ 100 km s−1), dark matter halos, and a nonconstant v max/σ 0 ratio. Finally, we report that tan ∣ ϕ ∣ ∝ ( − 1.18 ± 0.19 ) log v max ∝ ( − 0.48 ± 0.09 ) log M DM , providing a novel formulation between the geometry (i.e., the logarithmic spiral-arm pitch angle) and kinematics of spiral galaxy disks. While the v max–ϕ relation may facilitate distance estimations to face-on spiral galaxies through the Tully–Fisher relation and using ϕ as a proxy for v max, the M DM–ϕ relation provides a path for determining dark matter halo masses from imaging data alone. Furthermore, based on a spiral galaxy sample size that is double the size used previously, the self-consistent relations presented here provide dramatically revised constraints for theory and simulations.

The dynamics of the globular cluster M22 (NGC 6656)

AbstractWe have used the Hubble Space Telescope (HST) observations to measure proper motion of the globular cluster NGC 6656 (M22) with respect to the background bulge stars and its internal velocity dispersion profile. Based on the proper motion of the clusters, its space velocity and orbit are also calculated. The central velocity dispersion in radial and tangential components of the internal motion of cluster stars is 16.99 km s−1. We derive the mass-to-light ratio M/LV∼3.3 ± 0.2 which is relatively higher than the previous works.

Substructure in black hole scaling diagrams and implications for the coevolution of black holes and galaxies

AbstractOur multi-component photometric decomposition of the largest galaxy sample to date with dynamically-measured black hole masses nearly doubles the number of such galaxies. We have discovered substantially modified scaling relations between the black hole mass and the host galaxy properties, including the spheroid (bulge) stellar mass, the total galaxy stellar mass, and the central stellar velocity dispersion. These refinements partly arose because we were able to explore the scaling relations for various sub-populations of galaxies built by different physical processes, as traced by the presence of a disk, early-type versus late-type galaxies, or a Sérsic versus core-Sérsic spheroid light profile. The new relations appear fundamentally linked with the evolutionary paths followed by galaxies, and they have ramifications for simulations and formation theories involving both quenching and accretion.

On the Connection between Spiral Arm Pitch Angle and Galaxy Properties

Abstract We measure the pitch angle (φ) of spiral arms in a sample of 79 galaxies to perform a systematic study of the dependence of φ on galaxy morphology, mass, and kinematics to investigate the physical origin of spiral arms. We find that φ decreases (arms are more tightly wound), albeit with significant scatter, in galaxies with earlier Hubble type, more prominent bulges, higher concentration, and larger total galaxy stellar mass ( ). For a given concentration, galaxies with larger stellar masses tend to have tighter spiral arms, and vice versa. We also find that φ obeys a tight inverse correlation with central stellar velocity dispersion for σ c ≳ 100 km s−1, whereas φ remains approximately constant for σ c ≲ 100 km s−1. We demonstrate that the φ–σ c and φ– relations are projections of a more fundamental three-dimensional relation, such that pitch angle is determined by σ c for massive galaxies but by for less massive galaxies. Contrary to previous studies, we find that φ correlates only loosely with the galaxy’s shear rate. For a given shear rate, spirals generated from N-body simulations exhibit much higher φ than observed, suggesting that galactic disks are dynamically cooler (Toomre’s Q ≈ 1.2). Instead, the measured pitch angles show a much stronger relation with morphology of the rotation curve of the central region, such that galaxies with centrally peaked rotation curves have tight arms, while those with slow-rising rotation curves have looser arms. These behaviors are qualitatively consistent with predictions of density wave theory.

Fundamental Plane of Elliptical Galaxies in f(R) Gravity: The Role of Luminosity

The global properties of elliptical galaxies are connected through the so-called fundamental plane of ellipticals, which is an empirical relation between their parameters: effective radius, central velocity dispersion and mean surface brightness within the effective radius. We investigated the relation between the parameters of the fundamental plane equation and the parameters of modified gravity potential f ( R ) . With that aim, we compared theoretical predictions for circular velocity in f ( R ) gravity with the corresponding values from a large sample of observed elliptical galaxies. Besides, we consistently reproduced the values of coefficients of the fundamental plane equation as deduced from observations, showing that the photometric quantities like mean surface brightness are related to gravitational parameters. We show that this type of modified gravity, especially its power-law version— R n , is able to reproduce the stellar dynamics in elliptical galaxies. In addition, it is shown that R n gravity fits the observations very well, without the need for a dark matter.

Is the IMF in ellipticals bottom-heavy? Clues from their chemical abundances

We tested the implementation of different IMFs in our model for the chemical evolution of ellipticals, with the aim of reproducing the observed relations of [Fe/H] and [Mg/Fe] abundances with galaxy mass in a sample of early-type galaxies selected from the SPIDER-SDSS catalog. Abundances in the catalog were derived from averaged spectra, obtained by stacking individual spectra according to central velocity dispersion, as a proxy of galaxy mass. We tested initial mass functions already used in a previous work, as well as two new models, based on low-mass tapered ("bimodal") IMFs, where the IMF becomes either (1) bottom-heavy in more massive galaxies, or (2) is time-dependent, switching from top-heavy to bottom-heavy in the course of galactic evolution. We found that observations could only be reproduced by models assuming either a constant, Salpeter IMF, or a time-dependent distribution, as other IMFs failed. We further tested the models by calculating their M/L ratios. We conclude that a constant, time-independent bottom-heavy IMF does not reproduce the data, especially the increase of the $[\alpha/Fe]$ ratio with galactic stellar mass, whereas a variable IMF, switching from top to bottom-heavy, can match observations. For the latter models, the IMF switch always occurs at the earliest possible considered time, i.e. $t_{\text{switch}}= 0.1$ Gyr.

Calibrated, cosmological hydrodynamical simulations with variable IMFs – II. Correlations between the IMF and global galaxy properties

The manner in which the stellar initial mass function (IMF) scales with global galaxy properties is under debate. We use two hydrodynamical, cosmological simulations to predict possible trends for two self-consistent variable IMF prescriptions that respectively become locally bottom-heavy or top-heavy in high-pressure environments. Both simulations have been calibrated to reproduce the observed correlation between central stellar velocity dispersion and the excess mass-to-light ratio (MLE) relative to a Salpeter IMF by increasing the mass fraction of, respectively, dwarf stars or stellar remnants. We find trends of MLE with galaxy age, metallicity and [Mg/Fe] that agree qualitatively with observations. Predictions for correlations with luminosity, half-light radius, and black hole mass are presented. The significance of many of these correlations depends sensitively on galaxy selection criteria such as age, luminosity, and morphology. For an IMF with a varying high-mass end, some of these correlations are stronger than the correlation with the birth ISM pressure (the property that governs the form of the IMF), because in this case the MLE has a strong age dependence. Galaxies with large MLE tend to have overmassive central black holes. This indicates that the abnormally high MLE observed in the centres of some high-mass galaxies does not imply that overmassive BHs are merely the result of incorrect IMF assumptions, nor that excess M/L ratios are solely the result of overmassive BHs. Satellite galaxies tend to scatter toward high MLE due to tidal stripping, which may have significant implications for the inferred stellar masses of ultracompact dwarf galaxies.

The SAMI Galaxy Survey: Data Release Two with absorption-line physics value-added products

We present the second major release of data from the SAMI Galaxy Survey. Data Release Two includes data for 1559 galaxies, about 50% of the full survey. Galaxies included have a redshift range 0.004 < z < 0.113 and a large stellar mass range 7.5 < log (M_star/M_sun) < 11.6. The core data for each galaxy consist of two primary spectral cubes covering the blue and red optical wavelength ranges. For each primary cube we also provide three spatially binned spectral cubes and a set of standardised aperture spectra. For each core data product we provide a set of value-added data products. This includes all emission line value-added products from Data Release One, expanded to the larger sample. In addition we include stellar kinematic and stellar population value-added products derived from absorption line measurements. The data are provided online through Australian Astronomical Optics' Data Central. We illustrate the potential of this release by presenting the distribution of ~350,000 stellar velocity dispersion measurements from individual spaxels as a function of R/R_e, divided in four galaxy mass bins. In the highest stellar mass bin (log (M_star/M_sun)>11), the velocity dispersion strongly increases towards the centre, whereas below log (M_star/M_sun)<10 we find no evidence for a clear increase in the central velocity dispersion. This suggests a transition mass around log (M_star/M_sun) ~10 for galaxies with or without a dispersion-dominated bulge.

The Dearth of Differences between Central and Satellite Galaxies. II. Comparison of Observations with L-GALAXIES and EAGLE in Star Formation Quenching

Abstract As we demonstrated in Paper I, the quenched fractions of central and satellite galaxies as a function of halo mass are extremely similar, as long as one controls for stellar mass. The same holds for the quenched fractions as a function of central velocity dispersion, which is tightly correlated with black hole mass, as long as one controls for both stellar and halo masses. Here we use mock galaxy catalogs constructed from the latest semi-analytic model, L-GALAXIES, and the state-of-the-art hydrodynamical simulation, EAGLE, to investigate whether these models can reproduce the trends seen in the data. We also check how the group finder used to identify centrals and satellites impacts our results. We find that L-GALAXIES fails to reproduce the trends. The predicted quenched fraction of central galaxies increases sharply with halo mass around and with black hole mass around ∼106.5 M ⊙, while the predicted quenched fraction of satellites increases with both halo and black hole masses gradually. By contrast, centrals and satellites in EAGLE follow almost the same trend as seen in the data. We discuss the implications of our results for how feedback processes regulate galaxy quenching.

Shapley Supercluster Survey: mapping the filamentary network connecting the clusters

We have mapped the structure and connectivity of the Shapley supercluster core and its surroundings as traced by its member galaxies. To achieve this, we have carried out a new redshift survey of galaxies across a 21 square degree region (17×17 Mpc2) of the Shapley supercluster containing 11 rich clusters, all lying at z ~ 0.048. This survey aims to provide full spectroscopic coverage of galaxies for the Shapley Supercluster Survey (ShaSS), a multiwavelength survey based on high-quality optical ugri and near-infrared K-band imaging acquired with the 2.6-m VST and 4.1-m VISTA telescopes. Targets were selected from the VST images as having i < 18.0 and WISE/W1 < 15.5 mag, and the observations were carried out with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope. We present here redshift measurements for 4027 galaxies, of which 957 belong to the Shapley Supercluster. Including existing measurements, there are now reliable redshifts for 95 per cent of galaxies within the survey's magnitude limits over the 21 deg2 region. This has enabled us to: (i) obtain a detailed map of the galaxy number density across the whole region; (ii) identify new groups and cluster substructures; (iii) establish the existence of a stream of galaxies connecting A3559 to the supercluster core.We provide updated central redshifts and velocity dispersions of the 11 clusters, confirming that they all lie within 1300 km s-1 of the central cluster Abell 3558. These 11 systems are all inter-connected and lie within a coherent sheet of galaxies that fills the entire survey region without gaps. Clear velocity caustics extend right to the survey boundary, indicating that the entire structure is gravitationally bound and in the process of collapse.

A Test of MONDian Gravity in ∼300 Pressure-supported Elliptical Galaxies from the MaNGA Survey

Abstract Pressure-supported systems modeled under Modified Newtonian dynamics (MOND)ian extended gravity are expected to show an outer flattening in their velocity dispersion profiles. A characteristic scaling between the amplitude of the asymptotic velocity dispersion and the radius at which the flattening occurs is also expected. By comprehensively analyzing the dynamical behavior of ∼300 extremely low-rotating elliptical galaxies from the Mapping Nearby Galaxies at APO (MaNGA) survey, we show this type of pressure-supported system to be consistent with MONDian expectations, for a range of central velocity dispersion values of 60 km s−1 &lt; σ central &lt; 280 km s−1 and asymptotic velocity dispersion values of . We find that a universal velocity dispersion profile accurately describes the studied systems; the predicted kinematics of extended gravity are verified for all well-observed galaxies.

The central velocity dispersion of the Milky Way bulge

Context. Current spectroscopic and photometric surveys are providing a comprehensive view of the Milky Way bulge stellar population properties with unprecedented accuracy. This in turn allows us to explore the correlation between kinematics and stellar density distribution, crucial to constrain the models of Galactic bulge formation. Aims. The Giraffe Inner Bulge Survey (GIBS) revealed the presence of a velocity dispersion peak in the central few degrees of the Galaxy by consistently measuring high velocity dispersion in the three central most fields. Due to the suboptimal distribution of these fields, all being at negative latitudes and close to each other, the shape and extension of the sigma peak is poorly constrained. In this study we address this by adding new observations distributed more uniformly and in particular including fields at positive latitudes that were missing in GIBS. Methods. Observations with Multi Unit Spectroscopic Explorer (MUSE) were collected in four fields at (l, b) = (0°, +2°), (0°, −2°), (+1°, −1°), and (−1°, +2°). Individual stellar spectra were extracted for a number of stars comprised between ~500 and ~1200, depending on the seeing and the exposure time. Velocity measurements are done by cross-correlating observed stellar spectra in the CaT region with a synthetic template, and velocity errors are obtained through Monte Carlo simulations, cross-correlating synthetic spectra with a range of different metallicities and different noise characteristics. Results. We measure the central velocity dispersion peak within a projected distance from the Galactic center of ~280 pc, reaching σVGC ~ 140 km s−1 at b = −1°. This is in agreement with the results obtained previously by GIBS at negative longitude. The central sigma peak is symmetric with respect to the Galactic plane, with a longitude extension at least as narrow as predicted by GIBS. As a result of the Monte Carlo simulations we present analytical equations for the radial velocity measurement error as a function of metallicity and signal-to-noise ratio for giant and dwarf stars.

Stellar Mass Profiles of Quiescent Galaxies in Different Environments at z ∼ 0

We present the stellar mass profiles of 147 isolated quiescent galaxies in very low-density environments (i.e., void regions) in the local Universe ($0.01<z<0.06$) from the Sloan Digital Sky Survey. These galaxies have stellar masses between $ 9.8\lesssim \log(M_{\ast}/M_{\odot})\lesssim11.2$ and they represent $\sim15\%$ of the whole galaxy population in the void regions down to $M_{r} = -19$. We do not find any isolated quiescent galaxies with $\log(M_{\ast}/M_{\odot})\gtrsim11.2$. We compare the stellar mass profiles of these isolated quiescent galaxies with the profiles of stellar mass-matched samples of the quiescent galaxies in group and cluster environments. We find that, at fixed mass, quiescent galaxies in voids have similar central ($1$ kpc) mass densities ($\Sigma_1$) and central velocity dispersions ($\sigma_1$) compared to their counterparts in groups and clusters. We show that quiescent galaxies in voids have at most $10-25\%$ smaller half-mass (and half-light) sizes compared to quiescent galaxies in groups and clusters. We conclude that for the intermediate stellar mass range of $10^{10}-10^{11}M_{\odot}$ in the local Universe, environmental mechanisms have no significant additional effect on the mass profiles of the quiescent galaxies.

Calibrated, cosmological hydrodynamical simulations with variable IMFs I: Method and effect on global galaxy scaling relations

The recently inferred variations in the stellar initial mass function (IMF) among local high-mass early-type galaxies may require a reinterpretation of observations of galaxy populations and may have important consequences for the predictions of models of galaxy formation and evolution. We present a new pair of cosmological, hydrodynamical simulations based on the EAGLE model that self-consistently adopt an IMF that respectively becomes bottom- or top-heavy in high-pressure environments for individual star-forming gas particles. In such models, the excess stellar mass-to-light ($M/L$) ratio with respect to a reference IMF is increased due to an overabundance of low-mass dwarf stars or stellar remnants, respectively. Crucially, both pressure-dependent IMFs have been calibrated to reproduce the observed trends of increasing excess $M/L$ with central stellar velocity dispersion ($\sigma_e$) in early-type galaxies, while maintaining agreement with the observables used to calibrate the EAGLE model, namely the galaxy luminosity function, half-light radii of late-type galaxies, and black hole masses. We find that while the $M/L$ excess is a good measure of the IMF for low-mass slope variations, it depends strongly on the age of the stellar population for high-mass slope variations. The normalization of the [Mg/Fe]$-\sigma_e$ relation is decreased (increased) for bottom- (top-)heavy IMF variations, while the slope is not strongly affected. Bottom-heavy variations have little impact on galaxy metallicities, half-light radii of early-type galaxies, or star formation rates, while top-heavy variations significantly increase these quantities for high-mass galaxies, leading to tension with observations.

The Strong Rotation of M5 (NGC 5904) as Seen from the MIKiS Survey of Galactic Globular Clusters

In the context of the ESO-VLT Multi-Instrument Kinematic Survey (MIKiS) of Galactic globular clusters, we present the line-of-sight rotation curve and velocity dispersion profile of M5 (NGC 5904), as determined from the radial velocity of more than 800 individual stars observed out to 700" (~ 5 half-mass radii) from the center. We find one of the cleanest and most coherent rotation patterns ever observed for globular clusters, with a very stable rotation axis (having constant position angle of 145^o at all surveyed radii) and a well-defined rotation curve. The density distribution turns out to be flattened in the direction perpendicular to the rotation axis, with a maximum ellipticity of 0.15. The rotation velocity peak (~3 km/s in projection) is observed at ~0.6 half-mass radii, and its ratio with respect to the central velocity dispersion (~0.3-0.4 at 4 projected half-mass radii) indicates that ordered motions play a significant dynamical role. This result strengthens the growing empirical evidence of the kinematic complexity of Galactic globular clusters and motivates the need of fundamental investigations of the role of angular momentum in collisional stellar dynamics.

The Dearth of Difference between Central and Satellite Galaxies. I. Perspectives on Star Formation Quenching and AGN Activities

Abstract We investigate the quenching properties of central and satellite galaxies, utilizing the halo masses and central–satellite identifications from the Sloan Digital Sky Survey galaxy group catalog of Yang et al. We find that the quenched fractions of centrals and satellites of similar stellar masses have similar dependence on host halo mass. The similarity of the two populations is also found in terms of specific star formation rate and 4000 Å break. The quenched fractions of centrals and satellites of similar masses show similar dependencies on bulge-to-total light ratio, central velocity dispersion, and halo-centric distance in halos of given halo masses. The prevalence of optical/radio-loud active galactic nuclei is found to be similar for centrals and satellites at given stellar masses. All these findings strongly suggest that centrals and satellites of similar masses experience similar quenching processes in their host halos. We discuss implications of our results for the understanding of galaxy quenching.

Spatially Resolved Stellar Kinematics from LEGA-C: Increased Rotational Support in z ∼ 0.8 Quiescent Galaxies

Abstract We present stellar rotation curves and velocity dispersion profiles for 104 quiescent galaxies at z = 0.6–1 from the Large Early Galaxy Astrophysics Census (LEGA-C) spectroscopic survey. Rotation is typically probed across 10–20 kpc, or to an average of 2.7R e . Combined with central stellar velocity dispersions (σ 0) this provides the first determination of the dynamical state of a sample selected by a lack of star formation activity at large lookback time. The most massive galaxies (M ⋆ &gt; 2 × 1011 M ⊙) generally show no or little rotation measured at 5 kpc ( ∣ V 5 ∣ / σ 0 &lt; 0.2 in eight of ten cases), while ∼64% of less massive galaxies show significant rotation. This is reminiscent of local fast- and slow-rotating ellipticals and implies that low- and high-redshift quiescent galaxies have qualitatively similar dynamical structures. We compare ∣ V 5 ∣ / σ 0 distributions at z ∼ 0.8 and the present day by re-binning and smoothing the kinematic maps of 91 low-redshift quiescent galaxies from the Calar Alto Legacy Integral Field Area (CALIFA) survey and find evidence for a decrease in rotational support since z ∼ 1. This result is especially strong when galaxies are compared at fixed velocity dispersion; if velocity dispersion does not evolve for individual galaxies then the rotational velocity at 5 kpc was an average of 94 ± 22% higher in z ∼ 0.8 quiescent galaxies than today. Considering that the number of quiescent galaxies grows with time and that new additions to the population descend from rotationally supported star-forming galaxies, our results imply that quiescent galaxies must lose angular momentum between z ∼ 1 and the present, presumably through dissipationless merging, and/or that the mechanism that transforms star-forming galaxies also reduces their rotational support.

A quartet of black holes and a missing duo: probing the low end of the MBH–σ relation with the adaptive optics assisted integral-field spectroscopy

We present mass estimates of supermassive black holes in six nearby fast rotating early-type galaxies (NGC4339, NGC4434, NGC4474, NGC4551, NGC4578 and NGC4762) with effective stellar velocity dispersion around 100 km/s. We use near-infrared laser-guide adaptive optics observations with the GEMINI/NIFS to derive stellar kinematics in the galactic nuclei, and SAURON observations from the ATLAS3D Survey for large-scale kinematics. We build axisymmetric Jeans anisotropic models and axisymmetric Schwarzschild dynamical models. Both modelling approaches recover consistent orbital anisotropies and black hole masses within 1-2sigma confidence level, except for one galaxy for which the difference is just above the 3sigma level. Two black holes (NGC4339 and NGC4434) are amongst the largest outliers from the current black hole mass - velocity dispersion relation, with masses of $(4.3^{+4.8}_{-2.3})\times10^7$ and $(7.0^{+2.0}_{-2.8})\times10^7$ M$_\odot$, respectively ($3\sigma$ confidence level). The black holes in NGC4578 and NGC4762 lie on the scaling relation with masses of $(1.9^{+0.6}_{-1.4})\times10^7$ and $(2.3^{+0.9}_{-0.6})\times10^7$ M$_\odot$, respectively (3sigma confidence level). For two galaxies (NGC4474 and NGC4551) we are able to place upper limits on their black holes masses ($<7\times10^6$ and $<5\times10^6$ M$_\odot$, respectively, $3\sigma$ confidence level). The kinematics for these galaxies clearly indicate central velocity dispersion drops within a radius of 35 pc and 80 pc, respectively. These drops cannot be associated with cold stellar structures and our data do not have the resolution to exclude black holes with masses an order of magnitude smaller than the predictions. Parametrizing the orbital distribution in spherical coordinates, the vicinity of the black holes is characterized by isotropic or mildly tangential anisotropy.