854 research outputs found

    Prompt Electromagnetic Transients from Binary Black Hole Mergers

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    Binary black hole (BBH) mergers provide a prime source for current and future interferometric GW observatories. Massive BBH mergers may often take place in plasma-rich environments, leading to the exciting possibility of a concurrent electromagnetic (EM) signal observable by traditional astronomical facilities. However, many critical questions about the generation of such counterparts remain unanswered. We explore mechanisms that may drive EM counterparts with magnetohydrodynamic simulations treating a range of scenarios involving equal-mass black-hole binaries immersed in an initially homogeneous fluid with uniform, orbitally aligned magnetic fields. We find that the time development of Poynting luminosity, which may drive jet-like emissions, is relatively insensitive to aspects of the initial configuration. In particular, over a significant range of initial values, the central magnetic field strength is effectively regulated by the gas flow to yield a Poynting luminosity of 10451046ρ13M82ergs110^{45}-10^{46} \rho_{-13} M_8^2 \, {\rm erg}\,{\rm s}^{-1}, with BBH mass scaled to M8M/(108M)M_8 \equiv M/(10^8 M_{\odot}) and ambient density ρ13ρ/(1013gcm3)\rho_{-13} \equiv \rho/(10^{-13} \, {\rm g} \, {\rm cm}^{-3}). We also calculate the direct plasma synchrotron emissions processed through geodesic ray-tracing. Despite lensing effects and dynamics, we find the observed synchrotron flux varies little leading up to merger.Comment: 22 pages, 21 figures; additional reference + clarifying text added to match published versio

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

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    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

    Quantum cascade laser-based mid-infrared spectrochemical imaging of tissue and biofluids

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    Mid-infrared spectroscopic imaging is a rapidly emerging technique in biomedical research and clinical diagnostics that takes advantage of the unique molecular fingerprint of cells, tissue and biofluids to provide a rich biochemical image without the need for staining. Spectroscopic analysis allows for the objective classification of biological material at a molecular level.1 This “label free” molecular imaging technique has been applied to histology, cytology, surgical pathology, microbiology and stem cell research, and can be used to detect subtle changes to the genome, proteome and metabolome.2,3,4 The new wealth of biochemical information made available by this technique has the distinct potential to improve cancer patient outcome through the identification of earlier stages of disease, drug resistance, new disease states and high-risk populations.4 However, despite the maturity of this science, instrumentation that provide increased sample throughput, improved image quality, a small footprint, low maintenance and require minimal spectral expertise are essential for clinical translation

    Anatomy of the binary black hole recoil: A multipolar analysis

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    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

    Patients’ Perceptions of Pharmacist Intervention Through Pre-Screened Medication Therapy Management Service

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    Background: The continued challenge of time commitment in a community pharmacy setting is reported by pharmacists as the single largest setback in providing quality patient care. Additionally, when efforts are made by pharmacists to intervene on a patient’s therapy through medication therapy management (MTM), patient “no shows” further challenge an already busy community pharmacy world. Many studies show the value of a pharmacist-patient relationship. However, continued barriers prevent the value of this relationship to take full effect. While numerous methods of comprehensive medication review take place, the issue of establishing a model that best suits the needs of community pharmacy patients still exists. Statement of the Problem: To assess patients’ perceptions of pharmacist intervention through a pre-screened medication therapy management service at prescription pick-up. Description of Methodology: This study utilized a nonprobability convenience sampling of MTM participants at a local community pharmacy pickup for research. A questionnaire was designed to assess patients’ perceptions prior to and after the pharmacist intervention. All adult patients willing to participate in MTM services were included. After the MTM intervention, participants were encouraged to complete the questionnaire at home and mail it back to the pharmacy. The questionnaires were then collected from the pharmacy for review and data was analyzed with SPSS software. Results: Reported increased patient satisfaction and knowledge by survey following the MTM intervention. Unfortunately, the results were insignificant and the study did not achieve ideal power. Conclusions: The descriptive statistical results enumerated in this study do not reveal any applicable trends relating to the use of MTM services at-large. Despite these findings, however, all patients who commented on the intervention provided positive feedback. Further research is encouraged to appropriately assess the value of pharmacist-delivered MTM at prescription pick-up

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

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    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

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    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

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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 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
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