3,618 research outputs found

    Measuring Molecular, Neutral Atomic, and Warm Ionized Galactic Gas Through X-Ray Absorption

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    We study the column densities of neutral atomic, molecular, and warm ionized Galactic gas through their continuous absorption of extragalactic X-ray spectra at |b| > 25 degrees. For N(H,21cm) < 5x10^20 cm^-2 there is an extremely tight relationship between N(H,21cm) and the X-ray absorption column, N(xray), with a mean ratio along 26 lines of sight of N(xray)/N(H,21cm) = 0.972 +- 0.022. This is significantly less than the anticpated ratio of 1.23, which would occur if He were half He I and half He II in the warm ionized component. We suggest that the ionized component out of the plane is highly ionized, with He being mainly He II and He III. In the limiting case that H is entirely HI, we place an upper limit on the He abundance in the ISM of He/H <= 0.103. At column densities N(xray) > 5x10^20 cm^-2, which occurs at our lower latitudes, the X-ray absorption column N(xray) is nearly double N(H,21cm). This excess column cannot be due to the warm ionized component, even if He were entirely He I, so it must be due to a molecular component. This result implies that for lines of sight out of the plane with |b| ~ 30 degrees, molecular gas is common and with a column density comprable to N(H,21cm). This work bears upon the far infrared background, since a warm ionized component, anticorrelated with N(H,21cm), might produce such a background. Not only is such an anticorrelation absent, but if the dust is destroyed in the warm ionized gas, the far infrared background may be slightly larger than that deduced by Puget et al. (1996).Comment: 1 AASTeX file, 14 PostScript figure files which are linked within the TeX fil

    Observation of a multimode plasma response and its relationship to density pumpout and edge-localized mode suppression

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    Density pumpout and edge-localized mode (ELM) suppression by applied n=2 magnetic fields in low-collisionality DIII-D plasmas are shown to be correlated with the magnitude of the plasma response driven on the high-field side (HFS) of the magnetic axis but not the low-field side (LFS) midplane. These distinct responses are a direct measurement of a multimodal magnetic plasma response, with each structure preferentially excited by a different n=2 applied spectrum and preferentially detected on the LFS or HFS. Ideal and resistive magneto-hydrodynamic (MHD) calculations find that the LFS measurement is primarily sensitive to the excitation of stable kink modes, while the HFS measurement is primarily sensitive to resonant currents (whether fully shielding or partially penetrated). The resonant currents are themselves strongly modified by kink excitation, with the optimal applied field pitch for pumpout and ELM suppression significantly differing from equilibrium field alignment.This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, using the DIII-D National Fusion Facility, a DOE Office of Science user facility, under Awards No. DE-FC02-04ER54698, No. DE-AC02-09CH11466, No. DE-FG02-04ER54761, No. DE-AC05-06OR23100, No. DE-SC0001961, and No. DE-AC05-00OR22725. S. R. H. was supported by AINSE and ANSTO

    Texture of fermion mass matrices in partially unified theories

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    We investigate the texture of fermion mass matrices in theories with partial unification (for example SU(2)L×SU(2)R×SU(4)c SU(2)_L\times SU(2)_R\times SU(4)_c) at a scale 1012\sim 10^{12} GeV. Starting with the low energy values of the masses and the mixing angles, we find only two viable textures with atmost four texture zeros. One of these corresponds to a somewhat modified Fritzsch textures. A theoretical derivataion of these textures leads to new interesting relations among the masses and the mixing angles.Comment: 10 pages(Latex

    Intermediate scale as a source of lepton flavor violation in SUSY SO(10)

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    In supersymmetric SO(10) grand unified models, we examine the lepton flavor violation process μeγ\mu \rightarrow e\gamma from having the SU(2)R×_R\times U(1)BL_{B-L} gauge symmetry broken at an intermediate scale MIM_I below the SO(10) grand unification scale MGM_G. Even in the case that supersymmetry is broken by universal soft terms introduced at the scale MGM_G, we find significant rates for μeγ\mu\rightarrow e\gamma with MI1012M_I \sim 10^{12} GeV or less. These rates are further enhanced if the universal soft terms appear at a scale greater than MGM_G.Comment: 12 pages (Latex), 3 PS Figures (uuencoded, epsf.tex), small addition to discussion in the text, as to appear in Phys. Rev. D Rapid Communication

    First Astronomical Use of Multiplexed Transition Edge Bolometers

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    We present performance results based on the first astronomical use of multiplexed superconducting bolometers. The Fabry-Perot Interferometer Bolometer Research Experiment (FIBRE) is a broadband submillimeter spectrometer that achieved first light in June 2001 at the Caltech Submillimeter Observatory (CSO). FIBRE'S detectors are superconducting transition edge sensor (TES) bolometers read out by a SQUID multiplexer. The Fabry-Perot uses a low resolution grating to order sort the incoming light. A linear bolometer array consisting of 16 elements detects this dispersed light, capturing 5 orders simultaneously from one position on the sky. With tuning of the Fabry-Perot over one free spectral range, a spectrum covering Δλ/λ= 1/7 at a resolution of δλ/λ ≈ 1/1200 can be acquired. This spectral resolution is sufficient to resolve Doppler-broadened line emission from external galaxies. FIBRE operates in the 350 µm and 450 µm bands. These bands cover line emission from the important star formation tracers neutral carbon [Cl] and carbon monoxide (CO). We have verified that the multiplexed bolometers are photon noise limited even with the low power present in moderate resolution spectrometry

    The COBE Diffuse Infrared Background Experiment Search for the Cosmic Infrared Background: IV. Cosmological Implications

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    In this paper we examine the cosmological constraints of the recent DIRBE and FIRAS detection of the extragalactic background light between 125-5000 microns on the metal and star formation histories of the universe.Comment: 38 pages and 9 figures. Accepted for publications in The Astrophysical Journa

    Parental Satisfaction of Child\u27s Perioperative Care

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    Background Satisfaction in the hospital setting is an important component of both hospital funding and patient experience. When it comes to a child\u27s hospital experience, parent satisfaction of their child\u27s perioperative care is also necessary to understand. However, little research has been conducted on the predictors of this outcome. Therefore, the purpose of this current study was to validate a priori selected predictors for parental satisfaction in their child\u27s perioperative process. Methods Eight hundred and ten pediatric patients who underwent tonsillectomy and adenoidectomy surgery and their parents were included in this study. The primary outcome was assessed using a 21‐item parent satisfaction questionnaire resulting in three satisfaction scores: overall care satisfaction, OR/induction satisfaction, and total satisfaction. Results Descriptive statistics and correlational analysis found that sedative‐premedication, parental presence at anesthesia induction, child social functioning, parental anxiety, and language were all significant predictors of various components of the satisfaction score. Regression models, however, revealed that only parent anxiety and child social functioning remained significant predictors such that parents who reported lower state anxiety (OR/induction satisfaction: OR = 0.975, 95% CI [0.957, 0.994]; total satisfaction: OR = 0.968, 95% CI [0.943, 0.993]) and who had higher socially functioning children (overall care satisfaction: OR = 1.019, 95% CI [1.005, 1.033]; OR/induction satisfaction: OR = 1.011, 95% CI [1.000, 1.022]) were significantly more satisfied with the perioperative care they received. Conclusion Lower parent anxiety and higher child social functioning were predictive of higher parental satisfaction scores

    The X-ray Halo of GX 13+1

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    We present observations of the X-ray halo around the LMXB GX 13+1 from the Chandra X-ray telescope. The halo is caused by scattering in interstellar dust grains, and we use it to diagnose the line-of-sight position, size distribution, and density of the grains. Using the intrinsic energy resolution of Chandra's ACIS CCDs and the recent calibration observation of the Chandra point spread function (PSF), we were able to extract the halo fraction as a function of energy and off-axis angle. We define a new quantity, the ``halo coefficient,'' or the total halo intensity relative to the source at 1 keV, and measure it to be 1.50.1+0.51.5^{+0.5}_{-0.1} for GX 13+1. We find a relationship between this value and the dust size, density, and hydrogen column density along the line of sight to GX 13+1. We also conclude that our data does not agree with ``fluffy'' dust models that earlier X-ray halo observations have supported, and that models including an additional large dust grain population are not supported by these data.Comment: 19 pages, 13 figures, accepted by ApJ. New PSF calibration data used which remove uncertainties in original paper; paper substantially revise

    First Constraints on Source Counts at 350 Microns

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    We have imaged a \sim6 arcminute2^2 region in the Bo\"otes Deep Field using the 350 μ\mum-optimised second generation Submillimeter High Angular Resolution Camera (SHARC II), achieving a peak 1σ\sigma sensitivity of \sim5 mJy. We detect three sources above 3σ\sigma, and determine a spurious source detection rate of 1.09 in our maps. In the absence of 5σ5\sigma detections, we rely on deep 24 μ\mum and 20 cm imaging to deduce which sources are most likely to be genuine, giving two real sources. From this we derive an integral source count of 0.840.61+1.39^{+1.39}_{-0.61} sources arcmin2^{-2} at S>13S>13 mJy, which is consistent with 350 μ\mum source count models that have an IR-luminous galaxy population evolving with redshift. We use these constraints to consider the future for ground-based short-submillimetre surveys.Comment: accepted for publication in The Astrophysical Journa
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