2,033 research outputs found
Searches for supersymmetric particles in collisions up to 208 GeV and interpretation of the results within the MSSM
Searches for supersymmetric particles in collisions up to 208 GeV, and interpretation of the results within the MSSM
Searches for Supersymmetric Particles in Collisions up to 208 GeV and Interpretation of the Results within the MSSM
The Pierre Auger Observatory III: Other Astrophysical Observations
Astrophysical observations of ultra-high-energy cosmic rays with the Pierre
Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference,
Beijing, China, August 201
Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV
We describe the measurement of the depth of maximum, Xmax, of the
longitudinal development of air showers induced by cosmic rays. Almost four
thousand events above 10^18 eV observed by the fluorescence detector of the
Pierre Auger Observatory in coincidence with at least one surface detector
station are selected for the analysis. The average shower maximum was found to
evolve with energy at a rate of (106 +35/-21) g/cm^2/decade below 10^(18.24 +/-
0.05) eV and (24 +/- 3) g/cm^2/decade above this energy. The measured
shower-to-shower fluctuations decrease from about 55 to 26 g/cm^2. The
interpretation of these results in terms of the cosmic ray mass composition is
briefly discussed.Comment: Accepted for publication by PR
Operations of and Future Plans for the Pierre Auger Observatory
Technical reports on operations and features of the Pierre Auger Observatory,
including ongoing and planned enhancements and the status of the future
northern hemisphere portion of the Observatory. Contributions to the 31st
International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200
Suzaku Observation of the Black Hole Candidate MAXI J1836-194 in a Hard/Intermediate Spectral State
We report on a Suzaku observation of the newly discovered X-ray binary MAXI
J1836-194. The source is found to be in the hard/intermediate spectral state
and displays a clear and strong relativistically broadened iron emission line.
We fit the spectra with a variety of phenomenological, as well as physically
motivated disk reflection models, and find that the breadth and strength of the
iron line is always characteristic of emission within a few gravitational radii
around a black hole. This result is independent of the continuum used and
strongly points toward the central object in MAXI J1836-194 being a stellar
mass black hole rotating with a spin of (90% confidence). We
discuss this result in the context of spectral state definitions, physical
changes (or lack thereof) in the accretion disk and on the potential importance
of the accretion disk corona in state transitions.Comment: 11 pages, 9 Figures, Accepted for publication in Ap
A search for point sources of EeV photons
Measurements of air showers made using the hybrid technique developed with
the fluorescence and surface detectors of the Pierre Auger Observatory allow a
sensitive search for point sources of EeV photons anywhere in the exposed sky.
A multivariate analysis reduces the background of hadronic cosmic rays. The
search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an
energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been
detected. An upper limit on the photon flux has been derived for every
direction. The mean value of the energy flux limit that results from this,
assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial
direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in
which EeV cosmic ray protons are emitted by non-transient sources in the
Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical
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