600 research outputs found

    ALMA Observations of Circumnuclear Disks in Early Type Galaxies: 12CO(2-1) and Continuum Properties

    Full text link
    We present results from an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 2 program to map CO(2-1) emission in nearby early-type galaxies (ETGs) that host circumnuclear gas disks. We obtained 0.3\sim0.3''-resolution Band 6 observations of seven ETGs selected on the basis of dust disks in Hubble Space Telescope images. We detect CO emission in five at high signal-to-noise ratio with the remaining two only faintly detected. All CO emission is coincident with the dust and is in dynamically cold rotation. Four ETGs show evidence of rapid central rotation; these are prime candidates for higher-resolution ALMA observations to measure the black hole masses. In this paper we focus on the molecular gas and continuum properties. Total gas masses and H2_2 column densities for our five CO-bright galaxies are on average 108\sim10^8 MM_\odot and 1022.5\sim10^{22.5} cm2^{-2} over the \simkpc-scale disks, and analysis suggests that these disks are stabilized against gravitational fragmentation. The continuum emission of all seven galaxies is dominated by a central, unresolved source, and in five we also detect a spatially extended component. The \sim230 GHz nuclear continua are modeled as power laws ranging from Sνν0.4S_\nu \sim \nu^{-0.4} to ν1.6\nu^{1.6} within the observed frequency band. The extended continuum profiles of the two radio-bright (and CO-faint) galaxies are roughly aligned with their radio jet and suggests resolved synchrotron jets. The extended continua of the CO-bright disks are coincident with optically thick dust absorption and have spectral slopes that are consistent with thermal dust emission.Comment: 20 pages, 10 figures; accepted for publication in Ap

    Anatomy of the binary black hole recoil: A multipolar analysis

    Get PDF
    We present a multipolar analysis of the gravitational recoil computed in recent numerical simulations of binary black hole (BH) coalescence, for both unequal masses and non-zero, non-precessing spins. We show that multipole moments up to and including l=4 are sufficient to accurately reproduce the final recoil velocity (within ~2%) and that only a few dominant modes contribute significantly to it (within ~5%). We describe how the relative amplitudes, and more importantly, the relative phases, of these few modes control the way in which the recoil builds up throughout the inspiral, merger, and ringdown phases. We also find that the numerical results can be reproduced by an ``effective Newtonian'' formula for the multipole moments obtained by replacing the radial separation in the Newtonian formulae with an effective radius computed from the numerical data. Beyond the merger, the numerical results are reproduced by a superposition of three Kerr quasi-normal modes (QNMs). Analytic formulae, obtained by expressing the multipole moments in terms of the fundamental QNMs of a Kerr BH, are able to explain the onset and amount of ``anti-kick'' for each of the simulations. Lastly, we apply this multipolar analysis to help explain the remarkable difference between the amplitudes of planar and non-planar kicks for equal-mass spinning black holes.Comment: 28 pages, 20 figures, submitted to PRD; v2: minor revisions from referee repor

    Hip Anatomy and Ontogeny of Lower Limb Musculature in Three Species of Nonhuman Primates

    Get PDF
    The hip region is examined to determine what aspects of musculoskeletal anatomy are precociously developed in primate species with highly specialized modes of locomotion. Muscles of the hind limb were removed and weighed in each specimen, and the hip joint of selected specimens was studied in stained serial sections. No perinatal differences among species are evident, but in adults, the hip joint of Galago moholi (a leaping specialist) appears to have proportionally thick articular cartilage (relative to the subchondral plate) compared to two species of cheirogaleids. Muscle mass distribution in the hind limbs confirms previous observations that the quadriceps femoris muscle is especially large in Galago (in percent mass of the entire hind limb), while the hip region is smaller compared to the more quadrupedal cheirogaleids. Across age groups, the species with the least specialized locomotion as adults, Cheirogaleus medius, shows little or no change in proximal to distal percentage distribution of muscle mass. Galago has a larger percentage mass gain in the thigh. We suggest that muscle mass gain to specific limb segments may be a critical milestone for primates with extremely specialized modes of locomotion

    A Precision Measurement of the Mass of the Black Hole in NGC 3258 from High-Resolution ALMA Observations of its Circumnuclear Disk

    Get PDF
    We present 0.10\sim0.10^{\prime\prime}-resolution Atacama Large Millimeter/submillimeter Array (ALMA) CO(2-1) imaging of the arcsecond-scale (r150r \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 s1^{-1} at the disk's outer edge to >400>400 km s1^{-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 galaxy's mass profile within r=150r=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 galaxy's central region. The best model fit yields MBH=2.249×109M_\mathrm{BH} = 2.249\times10^9 MM_\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 MBHM_\mathrm{BH} in early-type galaxies containing circumnuclear gas disksComment: Accepted for publication in ApJ. 32 pages, 22 figure

    MEASUREMENT OF THE BLACK HOLE MASS IN NGC 1332 FROM ALMA OBSERVATIONS AT 0.044 ARCSECOND RESOLUTION

    Get PDF
    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 hole's gravitational radius of influence), we find M =(6.64 ) × 10 M . This observation demonstrates ALMA's powerful capability to determine the masses of supermassive black holes by resolving gas kinematics on small angular scales in galaxy nuclei. -1 +0.65 8 BH -0.63

    Catalysis of proline isomerization and molecular chaperone activity in a tug-of-war

    Get PDF
    Catalysis of cis/trans isomerization of prolines is important for the activity and misfolding of intrinsically disordered proteins. Catalysis is achieved by peptidylprolyl isomerases, a superfamily of molecular chaperones. Here, we provide atomic insight into a tug-of-war between cis/trans isomerization and molecular chaperone activity. Catalysis of proline isomerization by cyclophilin A lowers the energy barrier for \u3b1-synuclein misfolding, while isomerase-binding to a separate, disease-associated protein region opposes aggregation. We further show that cis/trans isomerization outpowers the holding activity of cyclophilin A. Removal of the proline isomerization barrier through posttranslational truncation of \u3b1-synuclein reverses the action of the proline isomerase and turns it into a potent molecular chaperone that inhibits protein misfolding. The data reveal a conserved mechanism of dual functionality in cis/trans isomerases and define its molecular determinants acting on intrinsically disordered proteins

    Introducing discrete frequency infrared technology for high-throughput biofluid screening

    Get PDF
    Accurate early diagnosis is critical to patient survival, management and quality of life. Biofluids are key to early diagnosis due to their ease of collection and intimate involvement in human function. Large-scale mid-IR imaging of dried fluid deposits offers a high-throughput molecular analysis paradigm for the biomedical laboratory. The exciting advent of tuneable quantum cascade lasers allows for the collection of discrete frequency infrared data enabling clinically relevant timescales. By scanning targeted frequencies spectral quality, reproducibility and diagnostic potential can be maintained while significantly reducing acquisition time and processing requirements, sampling 16 serum spots with 0.6, 5.1 and 15% relative standard deviation (RSD) for 199, 14 and 9 discrete frequencies respectively. We use this reproducible methodology to show proof of concept rapid diagnostics; 40 unique dried liquid biopsies from brain, breast, lung and skin cancer patients were classified in 2.4 cumulative seconds against 10 non-cancer controls with accuracies of up to 90%
    corecore