Cross Calibration of Imaging Air Cherenkov Telescopes with Fermi

An updated model for the synchrotron and inverse Compton emission from a population of high energy electrons of the Crab Nebula is used to reproduce the measured spectral energy distribution from radio to high energy gamma-rays. By comparing the predicted inverse Compton component with recent Fermi measurements of the nebula's emission, it is possible to determine the average magnetic field in the nebula and to derive the underlying electron energy distribution. The model calculation can then be used to cross calibrate the Fermi observations with ground based air shower measurements. The resulting energy calibration factors are derived and can be used for combining broad energy measurements taken with Fermi in conjunction with ground based measurements.Comment: 2009 Fermi Symposium, eConf Proceedings C091122, 5 pages, 5 figures, 3 table

Constraining Galactic dark matter with gamma-ray pixel counts statistics

Gamma-ray searches for new physics such as dark matter are often driven by investigating the composition of the extragalactic gamma-ray background (EGB). Classic approaches to EGB decomposition manifest in resolving individual point sources and dissecting the intensity spectrum of the remaining unresolved component. Furthermore, statistical methods have recently been proven to outperform the sensitivity of classic source detection algorithms in finding point-source populations in the unresolved flux regime. In this article, we employ the 1-point photon count statistics of eight years of Fermi-LAT data to resolve the population of extragalactic point sources and to decompose the diffuse isotropic background contribution for Galactic latitudes |b|>30 deg. We use three adjacent energy bins between 1 and 10 GeV. For the first time, we extend the analysis to incorporate a potential contribution from annihilating dark matter smoothly distributed in the Galaxy. We investigate the sensitivity reach of 1-point statistics for constraining the thermally-averaged self-annihilation cross section of dark matter, using different template models for the Galactic foreground emission. Given the official Fermi-LAT interstellar emission model, we set upper bounds on the DM self-annihilation cross section that are comparable with the constraints obtained by other indirect detection methods, in particular by the stacking analysis of several dwarf spheroidal galaxies.Comment: 11 pages, 7 figures, 1 table; v2: major changes improving the selection of the RO

Les droits fondamentaux dans la jurisprudence du Tribunal constitutionnel fédéral de R.F.A.

Une charte des droits et libertés n'est pas une déclaration sans valeur juridique, un document formaliste dénué de sens. En République fédérale d'Allemagne comme au Québec et au Canada, il s'agit en premier lieu d'un instrument important de transfert des pouvoirs, du politique vers le judiciaire. En décrivant dans un premier temps la structure des droits fondamentaux dans le texte constitutionnel de l'Allemagne de l'ouest, l'auteur expose ce rôle croissant du judiciaire résultant de l'élargissement des droits fondamentaux.A charter of liberties and freedoms is not a declaration devoid of legal value, a purely formal document without legal meaning. In the Federal Republic of Germany as in Québec and in Canada, it is in the first place an important instrument for transferring power from politics to the judiciary. By first describing the structure of fundamental rights in the constitutional text of West Germany, the author presents the increasing role of the judiciary resulting from the widening of fundamental rights

The Genderization of Crime Fiction from the Victorian Era to the Modern Day

Although Victorian crime fiction was originally “feminine” in its sensation fiction origins, it became increasingly masculinized as the genre developed. Eventually, Doyle’s Sherlock Holmes stories set forth the detective duo archetype of two white middle-class males, and it has remained the genre’s defining model ever since. This essay describes a book collection which explores this transition from feminine to masculine in the crime fiction genre of British literature and questions to what extent modern day authors are both challenging this model and remaining confined by it

New Constraints on Hidden Photons using Very High Energy Gamma-Rays from the Crab Nebula

Extensions of the standard model of particle physics, in particular those based on string theory, often predict a new U(1) gauge symmetry in a hidden sector. The corresponding gauge boson, called hidden photon, naturally interacts with the ordinary photon via gauge kinetic mixing, leading to photon - hidden photon oscillations. In this framework, one expects photon disappearance as a function of the mass of the hidden photon and the mixing angle, loosely constrained from theory. Several experiments have been carried out or are planned to constrain the mass-mixing plane. In this contribution we derive new constraints on the hidden photon parameters, using very high energy gamma-rays detected from the Crab Nebula, whose broad-band spectral characteristics are well understood. The very high energy gamma-ray observations offer the possibility to provide bounds in a broad mass range at a previously unexplored energy and distance scale. Using existing data that were taken with several Cherenkov telescopes, we discuss our results in the context of current constraints and consider the possibilities of using astrophysical data to search for hidden photon signatures.Comment: Proceedings of the "Heidelberg International Symposium on High Energy Gamma-Ray Astronomy", Heidelberg, Germany, July 7-11, 2008, submitted to AIP Conference Proceedings. 4 pages, 2 figures, 1 tabl