351,403 research outputs found

    Technique for analyzing human respiratory process

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    Electronic system /MIRACLE 2/ places frequency and gas flow rate of the respiratory process within a common frame of reference to render them comparable and compatible with ''real clock time.'' Numerous measurements are accomplished accurately on a strict one-minute half-minute, breath-by-breath, or other period basis

    Charge-dependent Azimuthal Correlations in Relativistic Heavy-ion Collisions and Electromagnetic Effects

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    We propose a scenario where the pattern of the recently observed charge-dependent azimuthal correlations can be understood qualitatively. This is based on the cluster picture and the assumption that the charged hadrons that flow outward from the surface of the overlapping region of the colliding nuclei move primarily parallel to the reaction plane. We also point out the there is a strong electric field induced by the transient magnetic field during the parton production in the initial phase of the relativistic heavy-ion collision and discuss its possible relevance to the scenario.Comment: Revised version to be published in Phys. Rev.

    X-shaped radio galaxies as observational evidence for the interaction of supermassive binary black holes and accretion disk at pc scale

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    A supermassive black hole binary may form during galaxy mergering. we investigate the interaction of the supermassive binary black holes (SMBBHs) and an accretion disk and show that the detected X-shaped structure in some FRII radio galaxies may be due to the interaction-realignment of inclined binary and accretion disk occurred within the pc scale of the galaxy center. We compare in detail the model and observations and show that the configuration is consistent very well with the observations of X-shaped radio sources. X-shaped radio feature form only in FRII radio sources due to the strong interaction between the binary and a standard disk, while the absence of X-shaped FRI radio galaxies is due to that the interaction between the binary and the radiatively inefficient accretion flow in FRI radio sources is negligible. It is suggested that the binary would keep misaligned with the outer disk for most of the life time of FRII radio galaxies and the orientation of jet in most FRII radio galaxies distributes randomly, while the jets in most FRI radio galaxies is expected to be vertical to the accretion disk and thus the major axis of host galaxy. We discuss the relationship of X-shaped and double-double radio galaxies (DDRGs). The model is applied in paticular to two X-shaped radio sources 4C+01.30 and 3C293 and one DDRG source J0116-473 and show that the SMBBHs in the three objects have black hole mass ratios q0.10.3q \sim 0.1 - 0.3.Comment: 35 pages, no figure, no table. Accepted for publication in MNRA

    Fisher Matrix Optimization of Cosmic Microwave Background Interferometers

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    We describe a method for forecasting errors in interferometric measurements of polarization of the cosmic microwave background (CMB) radiation, based on the use of the Fisher matrix calculated from the visibility covariance and relation matrices. In addition to noise and sample variance, the method can account for many kinds of systematic error by calculating an augmented Fisher matrix, including parameters that characterize the instrument along with the cosmological parameters to be estimated. The method is illustrated with examples of gain errors and errors in polarizer orientation. The augmented Fisher matrix approach is applicable to a much wider range of problems beyond CMB interferometry.Comment: Phys. Rev. D 93, 023512 (2016), v4 has no further change

    The Dependence of Spectral State Transition and Disk Truncation on Viscosity Parameter $\alpha

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    A wealth of Galactic accreting X-ray binaries have been observed both in low/hard state and high/soft state. The transition between these two states was often detected. Observation shows that the transition luminosity between these two states is different for different sources, ranging from 1% to 4% of the Eddington luminosity. Even for the same source the transition luminosity at different outbursts is also different. The transition can occur from 0.0069 to 0.15 Eddington luminosity. To investigate the underlying physics, we study the influence of viscosity parameter α\alpha on the transition luminosity on the basis of the disk-corona model for black holes. We calculate the mass evaporation rate for a wide range of viscosity parameter, 0.1α0.90.1\le \alpha\le 0.9. By fitting the numerical results, we obtain fitting formulae for both the transition accretion rate and the corresponding radius as a function of α\alpha. We find that the transition luminosity is very sensitive to the value of α\alpha, L/LEddα2.34L/L_{\rm Edd}\propto\alpha^{2.34}. For 0.1α0.60.1\le\alpha\le 0.6, the transition luminosity varies by two orders of magnitude, from 0.001 to 0.2 Eddington luminosity. Comparing with observations we find that the transition luminosity can be fitted by adjusting the value of α\alpha, and the model determined values of α\alpha are mostly in the range of observationally inferred value. Meanwhile we investigate the truncation of the disk in the low/hard state for some luminous sources. Our results are roughly in agreement with the observations.Comment: 8 pages, 3 figures,accepted by PAS
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