10,494 research outputs found

    Paying for Overhead: A Study of the Impact of Foundations' Overhead Payment Policies on Educational and Human Service Organizations

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    Examines the impact of foundations' overhead funding policies on educational and human services organizations, using data from two original surveys and six case studies

    Inflow-Outflow Model with Conduction and Self-Consistent Feeding for Sgr A*

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    We propose a two-temperature radial inflow-outflow model near Sgr A* with self-consistent feeding and conduction. Stellar winds from individual stars are considered to find the rates of mass injection and energy injection. These source terms help to partially eliminate the boundary conditions on the inflow. Electron thermal conduction is crucial for inhibiting the accretion. Energy diffuses out from several gravitational radii, unbinding more gas at several arcseconds and limiting the accretion rate to <1% of Bondi rate. We successfully fit the X-Ray surface brightness profile found from the extensive Chandra observations and reveal the X-Ray point source in the center. The super-resolution technique allows us to infer the presence and estimate the unabsorbed luminosity Lβ‰ˆ4β‹…1032ergsβˆ’1L\approx4\cdot10^{32}{\rm erg s^{-1}} of the point source. The employed relativistic heat capacity and direct heating of electrons naturally lead to low electron temperature Teβ‰ˆ4β‹…1010T_e\approx 4\cdot10^{10} K near the black hole. Within the same model we fit 86 GHz optically thick emission and obtain the order of magnitude agreement of Faraday rotation measure, thus achieving a single accretion model suitable at all radii.Comment: 6 pages, 5 figures, accepted by Ap
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