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Register a new userA Precision Measurement of the Mass of the Black Hole in NGC 3258 from High-Resolution ALMA Observations of its Circumnuclear Disk
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We present $sim0.10^{primeprime}-$resolution Atacama Large Millimeter/submillimeter Array (ALMA) CO(2$-$1) imaging of the arcsecond-scale ($r approx 150$ pc) dusty molecular disk in the giant elliptical galaxy NGC 3258. The data provide unprecedented resolution of cold gas disk kinematics within the dynamical sphere of influence of a supermassive black hole, revealing a quasi-Keplerian central increase in projected rotation speed rising from 280 km s$^{-1}$ at the disks outer edge to $>400$ km s$^{-1}$ near the disk center. We construct dynamical models for the rotating disk and fit beam-smeared model CO line profiles directly to the ALMA data cube. Our models incorporate both flat disks and tilted-ring disks that provide a better fit of the mildly warped structure in NGC 3258. We show that the exceptional angular resolution of the ALMA data makes it possible to infer the host galaxys mass profile within $r=150$ pc solely from the ALMA CO kinematics, without relying on optical or near-infrared imaging data to determine the stellar mass profile. Our model therefore circumvents any uncertainty in the black hole mass that would result from the substantial dust extinction in the galaxys central region. The best model fit yields $M_mathrm{BH} = 2.249times10^9$ $M_odot$ with a statistical model-fitting uncertainty of just 0.18%, and systematic uncertainties of 0.62% from various aspects of the model construction and 12% from uncertainty in the distance to NGC 3258. This observation demonstrates the full potential of ALMA for carrying out highly precise measurements of $M_mathrm{BH}$ in early-type galaxies containing circumnuclear gas disks
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We present Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 3 observations of CO(2-1) emission from the circumnuclear disk in the E/S0 galaxy NGC 1332 at 0.044 resolution. The disk exhibits regular rotational kinematics and central high-velocity emission (+/-500 km/s) consistent with the presence of a compact central mass. We construct models for a thin, dynamically cold disk in the gravitational potential of the host galaxy and black hole, and fit the beam-smeared model line profiles directly to the ALMA data cube. Model fits successfully reproduce the disk kinematics out to r=200 pc. Fitting models just to spatial pixels within projected r=50 pc of the nucleus (two times larger than the black holes gravitational radius of influence), we find M_BH=6.64(-0.63,+0.65)*10^8 solar masses. This observation demonstrates ALMAs powerful capability to determine the masses of supermassive black holes by resolving gas kinematics on small angular scales in galaxy nuclei.
We estimate the mass of the intermediate-mass black hole at the heart of the dwarf elliptical galaxy NGC 404 using Atacama Large Millimeter/submillimeter Array (ALMA) observations of the molecular interstellar medium at an unprecedented linear resolution of ~0.5 pc, in combination with existing stellar kinematic information. These ALMA observations reveal a central disc/torus of molecular gas clearly rotating around the black hole. This disc is surrounded by a morphologically and kinematically complex flocculent distribution of molecular clouds, that we resolve in detail. Continuum emission is detected from the central parts of NGC 404, likely arising from the Rayleigh-Jeans tail of emission from dust around the nucleus, and potentially from dusty massive star-forming clumps at discrete locations in the disc. Several dynamical measurements of the black hole mass in this system have been made in the past, but they do not agree. We show here that both the observed molecular gas and stellar kinematics independently require a ~5x10$^5$ Msun black hole once we include the contribution of the molecular gas to the potential. Our best estimate comes from the high-resolution molecular gas kinematics, suggesting the black hole mass of this system is 5.5$^{+4.1}_{-3.8}times$10$^5$ Msun (at the 99% confidence level), in good agreement with our revised stellar kinematic measurement and broadly consistent with extrapolations from the black hole mass - velocity dispersion and black hole mass - bulge mass relations. This highlights the need to accurately determine the mass and distribution of each dynamically important component around intermediate-mass black holes when attempting to estimate their masses.
We present Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 5 and Cycle 6 observations of CO(2$-$1) and CO(3$-$2) emission at 0.2$-$0.3 resolution in two radio-bright, brightest group/cluster early-type galaxies, NGC 315 and NGC 4261. The data resolve CO emission that extends within their black hole (BH) spheres of influence ($r_mathrm{g}$), tracing regular Keplerian rotation down to just tens of parsecs from the BHs. The projected molecular gas speeds in the highly inclined ($i>60^circ$) disks rises at least 500 km s$^{-1}$ near their galaxy centers. We fit dynamical models of thin-disk rotation directly to the ALMA data cubes, and account for the extended stellar mass distributions by constructing galaxy surface brightness profiles corrected for a range of plausible dust extinction values. The best-fit models yield $(M_mathrm{BH}/10^9,M_odot)=2.08pm0.01(mathrm{stat})^{+0.32}_{-0.14}(mathrm{sys})$ for NGC 315 and $(M_mathrm{BH}/10^9,M_odot)=1.67pm0.10(mathrm{stat})^{+0.39}_{-0.24}(mathrm{sys})$ for NGC 4261, the latter of which is larger than previous estimates by a factor of $sim$3. The BH masses are broadly consistent with the relations between BH masses and host galaxy properties. These are among the first ALMA observations to map dynamically cold gas kinematics well within the BH-dominated regions of radio galaxies, resolving the respective $r_mathrm{g}$ by factors of $sim$5$-$10. The observations demonstrate ALMAs ability to precisely measure BH masses in active galaxies, which will enable more confident probes of accretion physics for the most massive galaxies.
We present a supermassive black hole (SMBH) mass measurement in the Seyfert 1 galaxy NGC7469 using Atacama Large Millimeter/submillimeter Array (ALMA) observations of the atomic-${rm [CI]}$(1-0) and molecular-$^{12}$CO(1-0) emission lines at the spatial resolution of $approx0.3$ (or $approx$ 100 pc). These emissions reveal that NGC7469 hosts a circumnuclear gas disc (CND) with a ring-like structure and a two-arm/bi-symmetric spiral pattern within it, surrounded by a starbursting ring. The CND has a relatively low $sigma/Vapprox0.35$ ($rsim0.5$) and $sim0.19$ ($r>0.5$), suggesting that the gas is dynamically settled and suitable for dynamically deriving the mass of its central source. As is expected from X-ray dominated region (XDR) effects that dramatically increase an atomic carbon abundance by dissociating CO molecules, we suggest that the atomic [CI](1-0) emission is a better probe of SMBH masses than CO emission in AGNs. Our dynamical model using the ${rm [CI]}$(1-0) kinematics yields a $M_{rm BH}=1.78^{+2.69}_{-1.10}times10^7$M$_odot$ and $M/L_{rm F547M}=2.25^{+0.40}_{-0.43}$ (M$_odot$/L$_odot$). The model using the CO(1-0) kinematics also gives a consistent $M_{rm BH}$ with a larger uncertainty, up to an order of magnitude, i.e. $M_{rm BH}=1.60^{+11.52}_{-1.45}times10^7$M$_odot$. This newly dynamical $M_{rm BH}$ is $approx$ 2 times higher than the mass determined from the reverberation mapped (RM) method using emissions arising in the unresolved broad-line region (BLR). Given this new $M_{rm BH}$, we are able to constrain the specific RM dimensionless scaling factor of $f=7.2^{+4.2}_{-3.4}$ for the AGN BLR in NGC7469. The gas within the unresolved BLR thus has a Keplerian virial velocity component and the inclination of $iapprox11.0^circ$$_{-2.5}^{+2.2}$, confirming its face-on orientation in a Seyfert 1 AGN by assuming a geometrically thin BLR model.
The mass of a supermassive black hole ($M_mathrm{BH}$) is a fundamental property that can be obtained through observational methods. Constraining $M_mathrm{BH}$ through multiple methods for an individual galaxy is important for verifying the accuracy of different techniques, and for investigating the assumptions inherent in each method. NGC 4151 is one of those rare galaxies for which multiple methods can be used: stellar and gas dynamical modeling because of its proximity ($D=15.8pm0.4$ Mpc from Cepheids), and reverberation mapping because of its active accretion. In this work, we re-analyzed $H-$band integral field spectroscopy of the nucleus of NGC 4151 from Gemini NIFS, improving the analysis at several key steps. We then constructed a wide range of axisymmetric dynamical models with the new orbit-superposition code Forstand. One of our primary goals is to quantify the systematic uncertainties in $M_mathrm{BH}$ arising from different combinations of the deprojected density profile, inclination, intrinsic flattening, and mass-to-light ratio. As a consequence of uncertainties on the stellar luminosity profile arising from the presence of the AGN, our constraints on mbh are rather weak. Models with a steep central cusp are consistent with no black hole; however, in models with more moderate cusps, the black hole mass lies within the range of $0.25times10^7,M_odot lesssim M_mathrm{BH} lesssim 3times10^7,M_odot$. This measurement is somewhat smaller than the earlier analysis presented by Onken et al., but agrees with previous $M_mathrm{BH}$ values from gas dynamical modeling and reverberation mapping. Future dynamical modeling of reverberation data, as well as IFU observations with JWST, will aid in further constraining $M_mathrm{BH}$ in NGC 4151.
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