18 research outputs found

    The 2010 very high energy gamma-ray flare & 10 years of multi-wavelength observations of M 87

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    Abridged: The giant radio galaxy M 87 with its proximity, famous jet, and very massive black hole provides a unique opportunity to investigate the origin of very high energy (VHE; E>100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of super-massive black holes. M 87 has been established as a VHE gamma-ray emitter since 2006. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (~day), peak fluxes (Phi(>0.35 TeV) ~= (1-3) x 10^-11 ph cm^-2 s^-1), and VHE spectra. 43 GHz VLBA radio observations of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken ~3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core. The long-term (2001-2010) multi-wavelength light curve of M 87, spanning from radio to VHE and including data from HST, LT, VLA and EVN, is used to further investigate the origin of the VHE gamma-ray emission. No unique, common MWL signature of the three VHE flares has been identified.Comment: 19 pages, 5 figures; Corresponding authors: M. Raue, L. Stawarz, D. Mazin, P. Colin, C. M. Hui, M. Beilicke; Fig. 1 lightcurve data available online: http://www.desy.de/~mraue/m87

    Legitimacy intermediation in the multilevel European polity and its collapse in the euro crisis

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    This essay re-examines the dual – republican and liberal – foundations of democratic legitimacy in the Western traditions of normative political theory. Considered in isolation, the European Union conforms to liberal standards but cannot satisfy republican criteria. Given these conflicting standards, debates on the alleged European democratic deficit have remained inconclusive. Moreover, they have failed to pay sufficient attention to the multilevel character of the European polity and to the normative potential of legitimacy intermediation in its two-step compliance and legitimating relationships. I argue, however, that the capacity of democratic member states to legitimate the exercise of European governing functions is being destroyed in the present euro crisis, and I briefly discuss the implications of this new constellation.In der westlichen Tradition der normativen politischen Theorie beruht demokratische Legitimität auf der doppelten Grundlage republikanischer und liberaler Prinzipien. Für sich betrachtet entspricht die Europäische Union zwar liberalen Kriterien, aber eben nicht den republikanischen Anforderungen. Angesichts so unterschiedlicher Kriterien konnte es auch im Streit über das angebliche europäische Demokratiedefizit keine Einigung geben. Überdies ignorierte diese Diskussion den Mehrebenen-Charakter der europäischen Politik und das normative Potenzial der Legitimationsvermittlung zwischen Union und Bürgern durch die demokratisch verfassten Mitgliedstaaten. Die gegenwärtige Eurokrise allerdings zerstört die Fähigkeit demokratischer Mitgliedstaaten, die Ausübung europäischer Herrschaftsfunktionen zu legitimieren. Der Aufsatz erörtert die Implikationen dieser neuen Konstellation.1 Introduction 2 Legitimacy discourses The republican discourse The liberal discourse Differences 3 Constitutional democracies – and the European Union? 4 Legitimacy intermediation in the multilevel European polity 5 The end of legitimacy intermediation in the euro crisis Monetary Union and the failure of output legitimacy Rescuing the euro through supranational intervention 6 Legitimate supranational government? Input-oriented European legitimacy? 7 Reducing the burden on European legitimacy Reference

    Predicting risky drinking: is demoralization running up the tab?

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    Access to thesis permanently restricted to Ball State community only.College students frequently engage in patterns of problematic drinking which are associated with negative consequences (Osberg et al., 2010). However, intervention strategies have been shown to be ineffective (Henson et al., 2015). Prediction models include environmental factors, drinking motives, disinhibition, and negative affectivity with evidence suggesting that demoralization may be a factor (Moser et al., 2014). Thus, the current study examined if demoralization explained additional variance in problematic drinking not captured by current models. Participants were 334 midwestern college students (MAge = 18.8, SDage = 1.27, 72.2% women, 84.4% White) who completed measures of the aforementioned risk factors, demographics, and various drinking behaviors. Results of a linear regression, R2 = .42, indicated that disinhibition, = .35, coping motives, = .26, and enhancement motives, = .15, predicted disordered drinking. Results of a logistic regression indicated that coping motives, Exp B = 1.19, enhancement motives, Exp B = 1.16, and disinhibition, Exp B = 1.15, predicted binge drinking, Cox & Snell Pseudo R2 = .22. Coping motives, Exp B = 1.29, and enhancement motives, Exp B = 1.24, predicted risky drinking, Cox & Snell Pseudo R2 = .15. Disinhibition, Exp B = 1.11, and enhancement motives, Exp B = .91, predicted early onset drinking. Demoralization was not a significant predictor of problematic drinking. Results replicate past research supporting disinhibition, enhancement motives, and coping motives as robust predictors of problematic drinking (Sayette, 2017). However, support for other risk factors was not replicated. Findings suggest that patterns of problematic drinking may have distinct predictors. Further, the replication of disinhibition, enhancement motives, and coping motives implies that future research should examine if providing examples of adaptive reward and sensation seeking behaviors, and emotion regulation strategies could help to increase treatment efficacy. Limitations and future directions are discussed.Thesis (M.S.

    An Economic Anatomy of Optimal Climate Policy

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    This paper introduces geoengineering into an optimal control model of climate change economics. Together with mitigation and adaptation, carbon and solar geoengineering span the universe of possible climate policies. Their wildly different characteristics have important implications for climate policy. We show in the context of our model that: (i) the optimal carbon tax equals the marginal cost of carbon geoengineering; (ii) the introduction of either form of geoengineering leads to higher emissions yet lower temperatures; (iii) in a world with above-optimal cumulative emissions, only a complete set of instruments can minimize climate damages
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