48,843 research outputs found

    High Magnetic Field Rotation-powered Pulsars

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    Anomalous X-ray pulsars and soft gamma repeaters have recently emerged as a unified class of neutron stars, identified by dramatic X-ray and gamma-ray outbursts and via luminous X-ray pulsations, both thought to be powered by the decay of an enormous internal magnetic field. This "magnetar" hypothesis has raised the question of these objects' physical relationship with conventional rotation-powered pulsars (RPPs). The highest magnetic-field RPPs might therefore be expected to be transition objects between the two populations. The recently reported magnetar-like outburst of PSR J1846-0258, previously thought to be purely rotation-powered, clearly supports this suggestion. Here we review the observational properties of the highest magnetic-field RPPs known, and show some common characteristics that are notable among RPPs, which are plausibly related to their high fields. Using these objects, we consider the evidence for proposed "magneto-thermal evolution" in neutron stars, and argue that while some exists, it is not yet conclusive.Comment: 6 pages, 4 figures, Conference proceeding of "ASTROphysics of Neutron Stars 2010 -- a conference in honor of M. Ali Alpar", 2-6 August 2010, Cesme, Izmir, Turke

    Some Experimental Signatures to look for Time-reversal Violating superconductors

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    We discuss some experimental signatures associated with the topological structures of unconventional superconductor order parameters of form dx2y2+ixd_{x^2-y^2}+ix, where x=s,px±pyx=s,p_x \pm p_y, or dxyd_{xy}. Specifically, we study the topological surface states on the (110)(110) and equivalent surfaces of such superconductors which are observable in Andreev tunneling experiments, as well as evaluate the magnetic flux trapped in superconducting rings of such superconductors with multiple grain-boundary Josephson junctions. Previous experiments are examined and several new experiments suggested.Comment: 11 pages, 3 figure

    Reestimation of the production spectra of cosmic ray secondary positrons and electrons in the ISM

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    A detailed calculation of the production spectra of charged hadrons produced by interactions of cosmic rays in the interstellar medium is presented along with a thorough treatment of pion and muon decays. Newly parameterized inclusive cross sections of hadrons were used and exact kinematic limitations were taken into account. Single parametrized expressions for the production spectra of both secondary positrons and electrons in the energy range .1 to 100 GeV are presented. The results are compared with other authors' predictions. Equilibrium spectra using various models are also presented

    Fitting Pulsar Wind Tori. II. Error Analysis and Applications

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    We have applied the torus fitting procedure described in Ng & Romani (2004) to PWNe observations in the Chandra data archive. This study provides quantitative measurement of the PWN geometry and we characterize the uncertainties in the fits, with statistical errors coming from the fit uncertainties and systematic errors estimated by varying the assumed fitting model. The symmetry axis Ψ\Psi of the PWN are generally well determined, and highly model-independent. We often derive a robust value for the spin inclination ζ\zeta. We briefly discuss the utility of these results in comparison with new radio and high energy pulse measurementsComment: 15 pages, 3 figures, ApJ in pres
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