313 research outputs found

    Mid-J CO Emission in Nearby Seyfert Galaxies

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    We study for the first time the complete sub-millimeter spectra (450 GHz to 1550 GHz) of a sample of nearby active galaxies observed with the SPIRE Fourier Transform Spectrometer (SPIRE/FTS) onboard Herschel. The CO ladder (from Jup = 4 to 12) is the most prominent spectral feature in this range. These CO lines probe warm molecular gas that can be heated by ultraviolet photons, shocks, or X-rays originated in the active galactic nucleus or in young star-forming regions. In these proceedings we investigate the physical origin of the CO emission using the averaged CO spectral line energy distribution (SLED) of six Seyfert galaxies. We use a radiative transfer model assuming an isothermal homogeneous medium to estimate the molecular gas conditions. We also compare this CO SLED with the predictions of photon and X-ray dominated region (PDR and XDR) models.Comment: Proceedings of the Torus Workshop 2012 held at the University of Texas at San Antonio, 5-7 December 2012. C. Packham, R. Mason, and A. Alonso-Herrero (eds.); 6 pages, 3 figure

    Analysis and results of the industrial production of the superconducting Nb/Cu cavities for the LEP2 project

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    For the energy upgrade of the Large Electron Positron Collider at CERN 216 RF superconducting cavities were ordered from three European industrial firms (Ansaldo, Cerca, Siemens/Accel) at the beginning of 1991. These cavities are made of copper (Cu), internally coated with niobium (Nb) according to a procedure developed at CERN. Up to now about 147 of these cavities fulfilling the specifications have been produced. The large-scale statistics available and the use of dedicated analytical and optical inspection techniques shed new light on the relationship between production procedures, niobium film properties and cavity performance. An overview of this subject is presented, together with some significant trends and results

    Steering the Field Quality in the Production of the Main Quadrupoles of the Large Hadron Collider

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    The main issues concerning the field quality in the main quadrupoles of the Large Hadron Collider are presented. We show the trend plots for the focusing strength and multipoles at room temperature covering more than 2/3 of the production. We describe the correction of the coil layout to improve b6 at injection field level. A non-negligible fraction of the quadrupoles has been manufactured with collars featuring a magnetic permeability somewhat higher than the specified limits. We show plots for this anomaly. Field quality correlations to measurements in operational conditions are discussed. The dependence of field quality on cable manufacturer is analyse

    The Bending Magnets for the Proton Transfer Line of CNGS

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    The project "CERN neutrinos to Gran Sasso (CNGS)", a collaboration between CERN and the INFN (Gran Sasso Laboratory) in Italy, will study neutrino oscillations in a long base-line experiment. High-energy protons will be extracted from the CERN SPS accelerator, transported through a 727 m long transfer line and focused onto a graphite target to produce a beam of pions and kaons and subsequently neutrinos. The transfer line requires a total of 78 dipole magnets. They were produced in the framework of an in-kind contribution of Germany via DESY to the CNGS project. The normal conducting dipoles, built from laminated steel cores and copper coils, have a core length of 6.3 m, a 37 mm gap height and a nominal field range of 1.38 T - 1.91 T at a maximum current of 4950 A. The magnet design was a collaboration between CERN and BINP. The half-core production was subcontracted to EFREMOV Institute; the coil fabrication, magnet assembly and the field measurements were concluded at BINP in June 2004. The main design issues and results of the acceptance tests, including mechanical, electrical and magnetic field measurements, are discussed

    Insights into gas heating and cooling in the disc of NGC 891 from Herschel far-infrared spectroscopy

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    We present Herschel PACS and SPIRE spectroscopy of the most important far-infrared cooling lines in the nearby edge-on spiral galaxy, NGC 891: [CII] 158 μ\mum, [NII] 122, 205 μ\mum, [OI] 63, 145 μ\mum, and [OIII] 88 μ\mum. We find that the photoelectric heating efficiency of the gas, traced via the ([CII]+[OII]63)/FTIRF_{\mathrm{TIR}} ratio, varies from a mean of 3.5×\times103^{-3} in the centre up to 8×\times103^{-3} at increasing radial and vertical distances in the disc. A decrease in ([CII]+[OII]63)/FTIRF_{\mathrm{TIR}} but constant ([CII]+[OI]63)/FPAHF_{\mathrm{PAH}} with increasing FIR colour suggests that polycyclic aromatic hydrocarbons (PAHs) may become important for gas heating in the central regions. We compare the observed flux of the FIR cooling lines and total IR emission with the predicted flux from a PDR model to determine the gas density, surface temperature and the strength of the incident far-ultraviolet (FUV) radiation field, G0G_{0}. Resolving details on physical scales of ~0.6 kpc, a pixel-by-pixel analysis reveals that the majority of the PDRs in NGC 891's disc have hydrogen densities of 1 < log (nn/cm3^{-3}) < 3.5 experiencing an incident FUV radiation field with strengths of 1.7 < log G0G_0 < 3. Although these values we derive for most of the disc are consistent with the gas properties found in PDRs in the spiral arms and inter-arm regions of M51, observed radial trends in nn and G0G_0 are shown to be sensitive to varying optical thickness in the lines, demonstrating the importance of accurately accounting for optical depth effects when interpreting observations of high inclination systems. With an empirical relationship between the MIPS 24 μ\mum and [NII] 205 μ\mum emission, we estimate an enhancement of the FUV radiation field strength in the far north-eastern side of the disc.Comment: Accepted for publication in A&A. 25 pages, including 17 figures and 3 tables, abstract abridged for arXi

    The Quadrupole Magnets for the LHC Injection Transfer Lines

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    Two injection transfer lines, each about 2.8 km long, are being built to transfer protons at 450 GeV from the Super Proton Synchrotron (SPS) to the Large Hadron Collider (LHC). A total of 180 quadrupole magnets are required; they are produced in the framework of the contribution of the Russian Federation to the construction of the LHC. The classical quadrupoles, built from laminated steel cores and copper coils, have a core length of 1.4 m, an inscribed diameter of 32 mm and a strength of 53.5 T/m at a current of 530 A. The total weight of one magnet is 1.1 ton. For obtaining the required field quality at the small inscribed diameter, great care in the stamping of the laminations and the assembly of quadrants is necessary. Special instruments have been developed to measure, with a precision of some mm, the variations of the pole gaps over the full length of the magnet and correlate them to the obtained field distribution. The design has been developed in a collaboration between BINP and CERN. Fabrication and the magnetic measurements are done at BINP and should be finished at the end of the year 2000

    A Precision Measurement of pp Elastic Scattering Cross Sections at Intermediate Energies

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    We have measured differential cross sections for \pp elastic scattering with internal fiber targets in the recirculating beam of the proton synchrotron COSY. Measurements were made continuously during acceleration for projectile kinetic energies between 0.23 and 2.59 GeV in the angular range 30θc.m.9030 \leq \theta_{c.m.} \leq 90 deg. Details of the apparatus and the data analysis are given and the resulting excitation functions and angular distributions presented. The precision of each data point is typically better than 4%, and a relative normalization uncertainty of only 2.5% within an excitation function has been reached. The impact on phase shift analysis as well as upper bounds on possible resonant contributions in lower partial waves are discussed.Comment: 23 pages 29 figure

    Stimulation programs for pediatric drug research – do children really benefit?

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    Most drugs that are currently prescribed in pediatrics have not been tested in children. Pediatric drug studies are stimulated in the USA by the pediatric exclusivity provision under the Food and Drug Administration Modernization Act (FDAMA) that grants patent extensions when pediatric labeling is provided. We investigated the effectiveness of these programs in stimulating drug research in children, thereby increasing the evidence for safe and effective drug use in the pediatric population. All drugs granted pediatric exclusivity under the FDAMA were analyzed by studying the relevant summaries of medical and clinical pharmacology reviews of the pediatric studies or, if these were unavailable, the labeling information as provided by the manufacturer. A systematic search of the literature was performed to identify drug utilization patterns in children. From July 1998 to August 2006, 135 drug entities were granted pediatric exclusivity. Most frequent drug groups were anti-depressants and mood stabilizers, ACE inhibitors, lipid-lowering preparations, HIV antivirals, and non-steroidal anti-inflammatory and anti-rheumatic drugs. The distribution of the different drugs closely matched the distribution of these drugs over the adult market, and not the drug utilization by children

    Regional Variations in the Dense Gas Heating and Cooling in M51 from Herschel Far-infrared Spectroscopy

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    We present Herschel PACS and SPIRE spectroscopy of the most important far-infrared cooling lines in M51, [C II](158 μm), [N II](122 and 205 μm), [O I](63 and 145 μm), and [O III](88 μm). We compare the observed flux of these lines with the predicted flux from a photon-dominated region model to determine characteristics of the cold gas such as density, temperature, and the far-ultraviolet (FUV) radiation field, G_0, resolving details on physical scales of roughly 600 pc. We find an average [C II]/F_(TIR) of 4 × 10^(–3), in agreement with previous studies of other galaxies. A pixel-by-pixel analysis of four distinct regions of M51 shows a radially decreasing trend in both the FUV radiation field, G_0, and the hydrogen density, n, peaking in the nucleus of the galaxy, and then falling off out to the arm and interarm regions. We see for the first time that the FUV flux and gas density are similar in the differing environments of the arm and interarm regions, suggesting that the inherent physical properties of the molecular clouds in both regions are essentially the same

    Measurement of Spin Correlation Parameters ANN_{NN}, ASS_{SS}, and A_SL{SL} at 2.1 GeV in Proton-Proton Elastic Scattering

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    At the Cooler Synchrotron COSY/J\"ulich spin correlation parameters in elastic proton-proton (pp) scattering have been measured with a 2.11 GeV polarized proton beam and a polarized hydrogen atomic beam target. We report results for ANN_{NN}, ASS_{SS}, and A_SL{SL} for c.m. scattering angles between 30o^o and 90o^o. Our data on ASS_{SS} -- the first measurement of this observable above 800 MeV -- clearly disagrees with predictions of available of pp scattering phase shift solutions while ANN_{NN} and A_SL{SL} are reproduced reasonably well. We show that in the direct reconstruction of the scattering amplitudes from the body of available pp elastic scattering data at 2.1 GeV the number of possible solutions is considerably reduced.Comment: 4 pages, 4 figure
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