6,221 research outputs found

    The Transformation of Europe

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    Professor Weiler confronts the most complex and multi-faceted, and indeed the deepest change in contemporary Europe-the evolving relationship between the European Community and its Member States. Without denying the importance of 1992, he argues that it was preceded by two deeper mutations in the structure of the European Community, mutations we must understand if we are to grasp fully the significance of 1992. Tracing the evolution of the Community's political structure from 1958 to the present, the Article concentrates on constitutional aspects of the Community, specifically relationships between the Community and Member States along the axes of political power and legal norms. Professor Weiler then confronts the evolving question of the division of competences between Community and Member State. Analyzing law's role in the Community in its living political matrix rather than as abstract ideal, Weiler follows the evolution of these center-periphery tensions and concludes with some observations on ideology, ethos and political culture in post-1992 Europe

    An Auger test of the Cen A model of highest energy cosmic rays

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    If, as recently proposed by Farrar and Piran, Cen A is the source of cosmic rays detected above the Greisen-Zatsepin-Kuz'min cutoff, neutrons are ≈700\approx 700 more probable than protons to be observed along its line of sight. This is because the proton flux is rendered nearly isotropic by O(ÎŒ{\cal O}(\muG) intergalactic magnetic fields. With the anticipated aperture of the Southern Auger Observatory, one may expect on the order of 10 neutron events/year above 102010^{20} eV in the line of sight of Cen A

    End of the cosmic neutrino energy spectrum

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    There may be a high-energy cutoff of neutrino events in IceCube data. In particular, IceCube does not observe either continuum events above 2 PeV, or the Standard Model Glashow-resonance events expected at 6.3 PeV. There are also no higher energy neutrino signatures in the ANITA and Auger experiments. This absence of high-energy neutrino events motivates a fundamental restriction on neutrino energies above a few PeV. We postulate a simple scenario to terminate the neutrino spectrum that is Lorentz-invariance violating, but with a limiting neutrino velocity that is always smaller than the speed of light. If the limiting velocity of the neutrino applies also to its associated charged lepton, then a significant consequence is that the two-body decay modes of the charged pion are forbidden above two times the maximum neutrino energy, while the radiative decay modes are suppressed at higher energies. Such stabilized pions may serve as cosmic ray primaries.Comment: 6 pages. Version to appear in PL

    G328.4+0.2 : A large and luminous Crab-like supernova remnant

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    We report on radio continuum and HI observations of the radio source G328.4+0.2 using the Australia Telescope Compact Array. Our results confirm G328.4+0.2 to be a filled-center nebula with no surrounding shell, showing significant linear polarization and an almost flat spectral index. These results lead us to conclude that G328.4+0.2 is a Crab-like, or ``plerionic'', supernova remnant (SNR), presumably powered by an unseen central pulsar. HI absorption towards G328.4+0.2 puts a lower limit on its distance of 17.4 +/- 0.9 kpc, making it the largest (D=25 pc) and most luminous (L_R = 3e35 erg/s) Crab-like SNR in the Galaxy. We infer G328.4+0.2 to be significantly older than the Crab Nebula, but powered by a pulsar which is fast spinning (P<20 ms) and which has a comparatively low magnetic field (B<1e12 G). We propose G328.4+0.2, G74.9+1.2 and N157B as a distinct group of large-diameter, high-luminosity Crab-like SNRs, all powered by fast-spinning low-field pulsars.Comment: 7 pages, 3 embedded EPS figures, uses emulateapj.sty. Accepted to ApJ. Abstract corrected so that distance is now in kpc, not pc
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