The Black Hole Mass of NGC 4151: Comparison of Reverberation Mapping and Stellar Dynamical Measurements

We present a stellar dynamical estimate of the black hole (BH) mass in the Seyfert 1 galaxy, NGC 4151. We analyze ground-based spectroscopy as well as imaging data from the ground and space, and we construct 3-integral axisymmetric models in order to constrain the BH mass and mass-to-light ratio. The dynamical models depend on the assumed inclination of the kinematic symmetry axis of the stellar bulge. In the case where the bulge is assumed to be viewed edge-on, the kinematical data give only an upper limit to the mass of the BH of ∼ 4 × 107 M⊙ (1 ). If the bulge kinematic axis is assumed to have the same inclination as the symmetry axis of the large-scale galaxy disk (i.e., 23◦ relative to the line of sight), a best-fit dynamical mass between 4 − 5 × 107 M⊙ is obtained. However, because of the poor quality of the fit when the bulge is assumed to be inclined (as determined by the noisiness of the 2 surface and its minimum value), and because we lack spectroscopic data that clearly resolves the BH sphere of influence, we consider our measurements to be tentative estimates of the dynamical BH mass. With this preliminary result, NGC 4151 is now among the small sample of galaxies in which the BH mass has been constrained from two independent techniques, and the mass values we find for both bulge inclinations are in reasonable agreement with the recent estimate from reverberation mapping (4.57+0.57 −0.47 × 107 M⊙) published by Bentz et al

Supermassive Black Holes in Active Galactic Nuclei. I. The Consistency of Black Hole Masses in Quiescent and Active Galaxies

We report the first results of a program to measure accurate stellar velocity dispersions in the bulges of the host galaxies of active galactic nuclei (AGNs) for which accurate black hole (BH) masses have been determined via reverberation mapping. We find good agreement between BH masses obtained from reverberation mapping, and from the M(BH) - sigma relation as defined by quiescent galaxies, indicating a common relationship between active and quiescent black holes and their large-scale environments.Comment: Submitted to ApJ

A high-resolution infrared spectroscopic investigation of the halogen atom-HCN entrance channel complexes solvated in superfluid helium droplets

Rotationally resolved infrared spectra are reported for the X-HCN (X = Cl, Br, I) binary complexes solvated in helium nanodroplets. These results are directly compared with that obtained previously for the corresponding X-HF complexes [J. M. Merritt, J. K\"upper, and R. E. Miller, PCCP, 7, 67 (2005)]. For bromine and iodine atoms complexed with HCN, two linear structures are observed and assigned to the $^{2}\Sigma_{1/2}$ and $^{2}\Pi_{3/2}$ ground electronic states of the nitrogen and hydrogen bound geometries, respectively. Experiments for HCN + chlorine atoms give rise to only a single band which is attributed to the nitrogen bound isomer. That the hydrogen bound isomer is not stabilized is rationalized in terms of a lowering of the isomerization barrier by spin-orbit coupling. Theoretical calculations with and without spin-orbit coupling have also been performed and are compared with our experimental results. The possibility of stabilizing high-energy structures containing multiple radicals is discussed, motivated by preliminary spectroscopic evidence for the di-radical Br-HCCCN-Br complex. Spectra for the corresponding molecular halogen HCN-X$_{2}$ complexes are also presented.Comment: 20 pages, 15 figures, 6 tables, RevTe

The mass of the black hole in 3C 273

In this paper we apply the reverberation method to determine the mass of the black hole in 3C273 from the Ly a and C iv emission lines using archival IUE observations. Following the standard assumptions of the method, we find a maximum-likelihood estimate of the mass of 6.59 10^9 Mo, with a 1 sigma confidence interval 5.69-8.27 10^9 Mo. This estimate is more than one order of magnitude larger than that obtained in a previous study using Balmer lines. We reanalyze the optical data and show that the method applied to the Ha, Hb, and Hg Balmer lines produce mass estimates lower by a factor 2.5, but already much larger than the previous estimate derived from the same lines. The finding of such a high mass in a face-on object is a strong indication that the gas motion is not confined to the accretion disk. The new mass estimate makes 3C273 accreting with an accretion rate about six times lower than the Eddington rate. We discuss the implications of our result for the broad-line-region size and black-hole mass vs luminosity relationships for the set of objects for which reverberation black-hole masses have been obtained. We find that, while objects with super-Eddington luminosities might theoretically be possible, their existence is not necessarily implied by this sample.Comment: Accepted for publication in A&A. 10 pages, 9 figure

The optical emission line spectrum of Mark 110

We analyse in detail the rich emission line spectrum of Mark 110 to determine the physical conditions in the nucleus of this object, a peculiar NLS1 without any detectable Fe II emission associated with the broad line region and with a $\lambda5007/H\beta$ line ratio unusually large for a NLS1. We use 24 spectra obtained with the Marcario Low Resolution Spectrograph attached at the prime focus of the 9.2 m Hobby-Eberly telescope at the McDonald observatory. We fitted the spectrum by identifying all the emission lines (about 220) detected in the wavelength range 4200-6900 \AA (at rest). The narrow emission lines are probably produced in a region with a density gradient in the range 10$^{3}-10^{6}$ cm$^{-3}$ with a rather high column density (5$\times10^{21}$ cm$^{-2}$). In addition to a narrow line system, three major broad line systems with different line velocity and width are required. We confirm the absence of broad Fe II emission lines. We speculate that Mark 110 is in fact a BLS1 with relatively "narrow" broad lines but with a BH mass large enough compared to its luminosity to have a lower than Eddington luminosity.Comment: 13 pages, 5 figures, accepted by A&

Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. II. A Homogeneous Analysis of a Large Reverberation-Mapping Database

We present improved black hole masses for 35 active galactic nuclei (AGNs) based on a complete and consistent reanalysis of broad emission-line reverberation-mapping data. From objects with multiple line measurements, we find that the highest precision measure of the virial product is obtained by using the cross-correlation function centroid (as opposed to the cross-correlation function peak) for the time delay and the line dispersion (as opposed to full width half maximum) for the line width and by measuring the line width in the variable part of the spectrum. Accurate line-width measurement depends critically on avoiding contaminating features, in particular the narrow components of the emission lines. We find that the precision (or random component of the error) of reverberation-based black hole mass measurements is typically around 30%, comparable to the precision attained in measurement of black hole masses in quiescent galaxies by gas or stellar dynamical methods. Based on results presented in a companion paper by Onken et al., we provide a zero-point calibration for the reverberation-based black hole mass scale by using the relationship between black hole mass and host-galaxy bulge velocity dispersion. The scatter around this relationship implies that the typical systematic uncertainties in reverberation-based black hole masses are smaller than a factor of three. We present a preliminary version of a mass-luminosity relationship that is much better defined than any previous attempt. Scatter about the mass-luminosity relationship for these AGNs appears to be real and could be correlated with either Eddington ratio or object inclination.Comment: 61 pages, including 8 Tables and 16 Figures. Accepted for publication in The Astrophysical Journa

The Black Hole Mass of NGC 4151: Comparison of Reverberation Mapping and Stellar Dynamical Measurements

We present a stellar dynamical estimate of the black hole (BH) mass in the Seyfert 1 galaxy, NGC 4151. We analyze ground-based spectroscopy as well as imaging data from the ground and space, and we construct 3-integral axisymmetric models in order to constrain the BH mass and mass-to-light ratio. The dynamical models depend on the assumed inclination of the kinematic symmetry axis of the stellar bulge. In the case where the bulge is assumed to be viewed edge-on, the kinematical data give only an upper limit to the mass of the BH of ~4e7 M_sun (1 sigma). If the bulge kinematic axis is assumed to have the same inclination as the symmetry axis of the large-scale galaxy disk (i.e., 23 degrees relative to the line of sight), a best-fit dynamical mass between 4-5e7 M_sun is obtained. However, because of the poor quality of the fit when the bulge is assumed to be inclined (as determined by the noisiness of the chi^2 surface and its minimum value), and because we lack spectroscopic data that clearly resolves the BH sphere of influence, we consider our measurements to be tentative estimates of the dynamical BH mass. With this preliminary result, NGC 4151 is now among the small sample of galaxies in which the BH mass has been constrained from two independent techniques, and the mass values we find for both bulge inclinations are in reasonable agreement with the recent estimate from reverberation mapping (4.57[+0.57/-0.47]e7 M_sun) published by Bentz et al.Comment: 20 pages, including 11 low-res figures. Accepted for publication in ApJ. High resolution version available upon reques

Supermassive Black Holes in Active Galactic Nuclei. II. Calibration of the M-sigma Relationship for AGNs

We calibrate reverberation-based black hole masses in active galactic nuclei (AGNs) by using the correlation between black hole mass, M, and bulge/spheroid stellar velocity dispersion, sigma. We use new measurements of sigma for 6 AGNs and published velocity dispersions for 10 others, in conjunction with improved reverberation mapping results, to determine the scaling factor required to bring reverberation-based black hole masses into agreement with the quiescent galaxy M-sigma relationship. The scatter in the AGN black hole masses is found to be less than a factor of 3. The current observational uncertainties preclude use of the scaling factor to discriminate between broad-line region models.Comment: 16 pages, including 3 figures. Accepted for publication in Ap

DEVELOPMENT OF CORROSION-RESISTANT ALLOYS FOR USE AS CONTAINER MATERIALS FOR DECLADDING SOLUTIONS OR AS WELDING ALLOYS

Twenty-four experimental alloys were developed and evaluated as container materials or welding alloys for use with Sulfex and Niflex decladding solutions. Niflex solutions which were more corrosive than Sulfex solutions to most of the experimental alloys, produced severe localized attack on weldments made on vacuum-melted Hastelloy F with the experimental alloys. However, several of the alloys, when self-welded, were not selectively attacked. Some of these showed a substantial improvement in resistance to the decladding solutions. The most promising alloys were based on either 45 wt.% nickel--22 wt.% chromium or 50 wt.% nickel--25 wt.% chromium, with at least 6 wt.% molybdenum, and 1 wt.% titanium, 0.6 wt.% manganese, 0.4 wt. % silicon, 0.02 wt.% carbon, and the balance, iron. The alloy most resistant to both solutions contained 6 wt.% molybdenum and 1 wt.% copper in the 50 wt.% nickel--25 wt.% chromium base. Its corrosion rate of 22 mils per month in Niflex, with no selective attack, was significantly lower than the 105 mils per month recorded for Hastelloy F. Even lower rates would be expected under the less stringent conditions of actual process operation. Indications are that more resistance might be obtained by increasing the chromium and nickel contents. (auth

Supermassive Black Hole Mass Regulated by Host Galaxy Morphology

We investigated the relationship between supermassive black hole (SMBH) mass and host starburst luminosity in Seyfert galaxies and Palomar-Green QSOs, focusing on the host galaxy morphology. Host starburst luminosity was derived from the 11.3 micron polycyclic aromatic hydrocarbon luminosity. We found that the SMBH masses of elliptical-dominated host galaxies are more massive than those of disk-dominated host galaxies statistically. We also found that the SMBH masses of disk-dominated host galaxies seem to be suppressed even under increasing starburst luminosity. These findings imply that final SMBH mass is strongly regulated by host galaxy morphology. This can be understood by considering the radiation drag model as the SMBH growth mechanism, taking into account the radiation efficiency of the host galaxy.Comment: 6 pages, 1 figure; accepted for publication in MNRA