5,929 research outputs found

    «Prozessintelligenz» : Gegenstand und Ziele der Studie

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    «Intelligente Prozesse, «intelligentes Prozessmanagement», «iBPM» sind Schlagworte, die in erster Linie eingesetzt werden, um Technologien zu vermarkten. Die Begriffe lassen viel Raum für Interpretation und Assoziationen. Können Unternehmen den Hype ignorieren oder bietet «Prozessintelligenz» die Chance, das Prozessmanagement aus einem anderen Blickwinkel zu betrachten und weiterzuentwickeln? Doch was ist Prozessintelligenz? Welche Lösungsansätze, Erfahrungen und Erfolgsmuster gibt es bereits in Unternehmen? Welche Methoden und Werkzeuge kommen zum Einsatz, um Prozesse «intelligenter» zu machen? Diesen Fragen hat sich die Business-Process-Management-Studie 2015 gestellt, mit der das Institut für Wirtschaftsinformatik der Zürcher Hochschule für Angewandte Wissenschaften School of Management and Law seit 2011 regelmässig Status quo und Best Practices im deutschsprachigen Raum erhebt

    [The Impact of Nuclear Star Formation on Gas Inflow to AGN

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    Our adaptive optics observations of nearby AGN at spatial resolutions as small as 0.085arcsec show strong evidence for recent, but no longer active, nuclear star formation. We begin by describing observations that highlight two contrasting methods by which gas can flow into the central tens of parsecs. Gas accumulation in this region will inevitably lead to a starburst, and we discuss the evidence for such events. We then turn to the impact of stellar evolution on the further inflow of gas by combining a phenomenological approach with analytical modelling and hydrodynamic simulations. These complementary perspectives paint a picture in which all the processes are ultimately regulated by the mass accretion rate into the central hundred parsecs, and the ensuing starburst that occurs there. The resulting supernovae delay accretion by generating a starburst wind, which leaves behind a clumpy interstellar medium. This provides an ideal environment for slower stellar outflows to accrete inwards and form a dense turbulent disk on scales of a few parsecs. Such a scenario may resolve the discrepancy between the larger scale structure seen with adaptive optics and the small scale structure seen with VLTI.Comment: to appear in: Co-Evolution of Central Black Holes and Galaxies; 7 page

    Hyperspherical Harmonics, Separation of Variables and the Bethe Ansatz

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    The relation between solutions to Helmholtz's equation on the sphere Sn1S^{n-1} and the [{\gr sl}(2)]^n Gaudin spin chain is clarified. The joint eigenfuctions of the Laplacian and a complete set of commuting second order operators suggested by the RR--matrix approach to integrable systems, based on the loop algebra \wt{sl}(2)_R, are found in terms of homogeneous polynomials in the ambient space. The relation of this method of determining a basis of harmonic functions on Sn1S^{n-1} to the Bethe ansatz approach to integrable systems is explained.Comment: 14 pgs, Plain Tex, preprint CRM--2174 (May, 1994

    Spitzer Quasar and ULIRG evolution study (QUEST): I. The origin of the far infrared continuum of QSOs

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    This paper addresses the origin of the far-infrared (FIR) continuum of QSOs, based on the Quasar and ULIRG Evolution Study (QUEST) of nearby QSOs and ULIRGs using observations with the Spitzer Space Telescope. For 27 Palomar-Green QSOs at z <~ 0.3, we derive luminosities of diagnostic lines ([NeII]12.8um, [NeV]14.3um, [OIV]25.9um) and emission features (PAH7.7um emission which is related to star formation), as well as continuum luminosities over a range of mid- to far-infrared wavelengths between 6 and 60um. We detect star-formation related PAH emission in 11/26 QSOs and fine-structure line emission in all of them, often in multiple lines. The detection of PAHs in the average spectrum of sources which lack individual PAH detections provides further evidence for the widespread presence of PAHs in QSOs. Similar PAH/FIR and [NeII]/FIR ratios are found in QSOs and in starburst-dominated ULIRGs and lower luminosity starbursts. We conclude that the typical QSO in our sample has at least 30% but likely most of the far-infrared luminosity (~ 10^(10...12)Lsun) arising from star formation, with a tendency for larger star formation contribution at the largest FIR luminosities. In the QSO sample, we find correlations between most of the quantities studied including combinations of AGN tracers and starburst tracers. The common scaling of AGN and starburst luminosities (and fluxes) is evidence for a starburst-AGN connection in luminous AGN. Strong correlations of far-infrared continuum and starburst related quantities (PAH, low excitation [NeII]) offer additional support for the starburst origin of far-infrared emission.Comment: 39 pages, 8 figures, accepted for publication in Ap

    Mid-Infrared Diagnostics of LINERs

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    We report results from the first mid-infrared spectroscopic study of a comprehensive sample of 33 LINERs, observed with the Spitzer Space Telescope. We compare the properties of two different LINER populations: infrared-faint LINERs, with LINER emission arising mostly in compact nuclear regions, and infrared-luminous LINERs, which often show spatially extended (non-AGN) LINER emission. We show that these two populations can be easily distinguished by their mid-infrared spectra in three different ways: (i) their mid-IR spectral energy distributions (SEDs), (ii) the emission features of polycyclic aromatic hydrocarbons (PAHs), and (iii) various combinations of IR fine-structure line ratios. IR-luminous LINERs show mid-IR SEDs typical of starburst galaxies, while the mid-IR SEDs of IR-faint LINERs are much bluer. PAH flux ratios are significantly different in the two groups. Fine structure emission lines from highly excited gas, such as [O IV], are detected in both populations, suggesting the presence of an additional AGN also in a large fraction of IR-bright LINERs, which contributes little to the combined mid-IR light. The two LINER groups occupy different regions of mid-infrared emission-line excitation diagrams. The positions of the various LINER types in our diagnostic diagrams provide important clues regarding the power source of each LINER type. Most of these mid-infrared diagnostics can be applied at low spectral resolution, making AGN- and starburst-excited LINERs distinguishable also at high redshifts.Comment: 11 pages, including 2 eps figures, accepted for publication in ApJ

    Double-beta decay Q values of 130Te, 128Te, and 120Te

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    The double-beta decay Q values of 130Te, 128Te, and 120Te have been determined from parent-daughter mass differences measured with the Canadian Penning Trap mass spectrometer. The 132Xe-129Xe mass difference, which is precisely known, was also determined to confirm the accuracy of these results. The 130Te Q value was found to be 2527.01(32) keV which is 3.3 keV lower than the 2003 Atomic Mass Evaluation recommended value, but in agreement with the most precise previous measurement. The uncertainty has been reduced by a factor of 6 and is now significantly smaller than the resolution achieved or foreseen in experimental searches for neutrinoless double-beta decay. The 128Te and 120Te Q values were found to be 865.87(131) keV and 1714.81(125) keV, respectively. For 120Te, this reduction in uncertainty of nearly a factor of 8 opens up the possibility of using this isotope for sensitive searches for neutrinoless double-electron capture and electron capture with positron emission.Comment: 5 pages, 2 figures, submitted to Physical Review Letter

    Remark on charge conjugation in the non relativistic limit

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    We study the non relativistic limit of the charge conjugation operation C\cal C in the context of the Dirac equation coupled to an electromagnetic field. The limit is well defined and, as in the relativistic case, C\cal C, P\cal P (parity) and T\cal T (time reversal) are the generators of a matrix group isomorphic to a semidirect sum of the dihedral group of eight elements and Z2\Z_2. The existence of the limit is supported by an argument based in quantum field theory. Also, and most important, the limit exists in the context of galilean relativity. Finally, if one complexifies the Lorentz group and therefore the galilean spacetime xμx_\mu, then the explicit form of the matrix for C\cal C allows to interpret it, in this context, as the complex conjugation of the spatial coordinates: xx\vec{x} \to \vec{x}^*. This result is natural in a fiber bundle description.Comment: 8 page

    PTF11kx: A Type-Ia Supernova with a Symbiotic Nova Progenitor

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    There is a consensus that Type-Ia supernovae (SNe Ia) arise from the thermonuclear explosion of white dwarf stars that accrete matter from a binary companion. However, direct observation of SN Ia progenitors is lacking, and the precise nature of the binary companion remains uncertain. A temporal series of high-resolution optical spectra of the SN Ia PTF 11kx reveals a complex circumstellar environment that provides an unprecedentedly detailed view of the progenitor system. Multiple shells of circumsteller are detected and the SN ejecta are seen to interact with circumstellar material (CSM) starting 59 days after the explosion. These features are best described by a symbiotic nova progenitor, similar to RS Ophiuchi.Comment: 27 pages, 5 figures. In pres
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