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AbstractAbstract
[en] The Large Area Telescope (LAT) on board the Fermi satellite, launched on June 11 2008, is sensitive to γ rays from 20 MeV to over 300 GeV. γ-ray pulsations from 148 pulsars to date have been detected with the Fermi-LAT, 117 are detailed in the Second Fermi-LAT Gamma-ray Pulsar Catalog (2PC). Pulsars are by far the largest GeV source class in the Milky Way. Studies of the increasing γ-ray pulsar sample bring important constraints on theoretical γ-ray emission models and enable breakthroughs in our understanding of pulsars. This thesis presents detections of seven faint γ-ray pulsars that are already known at radio wavelengths, including four young or middle aged pulsars and three millisecond pulsars (MSPs). Spectral analysis and light curve characterizations are detailed and compared to the 2PC sample. These detections have the special interest of allowing us to probe and extend the parameter space of the current population. They illustrate the inherent bias in 2PC and mark the transition from the early part (bright pulsars) to the later part (faint pulsars) of the Fermi mission. Theoretical model developments and a complete census of Galactic neutron star populations will benefit from more detections of weak pulsars in the years to come. Some high γ-ray efficiency pulsars in 2PC are studied in this thesis. Investigations on different parameters which influence the efficiency result in a few candidates for which a large moment of inertia is necessary to cure the high efficiency paradox. Fermi γ-ray observations seem to bring independent constraints on the moment of inertia and equations of state of neutron stars. (author)
[fr]
Le Large Area Telescope (LAT) a bord du satellite Fermi, lance le 11 Juin 2008, est sensible au rayonnement γ de 20 MeV a plus de 300 GeV. 148 pulsars γ a ce jour ont ete detectes avec le Fermi-LAT, dont 117 sont detailles dans le Deuxieme Catalogue de Pulsars γ de Fermi (2PC). Les pulsars forment la plus grande classe de sources au GeV dans la Voie Lactee. Les etudes de pulsars γ apportent des contraintes importantes sur les modeles d'emission γ et permettent des percees dans notre comprehension des pulsars. Cette these presente des detections de sept pulsars γ faibles deja connus en radio, dont quatre jeunes ou d'ages moyens et trois millisecondes (MSP). L'analyse spectrale et la caracterisation des courbes de lumiere sont decrites et comparees a la population de 2PC. Ces detections ont l'interet particulier de sonder et d'etendre l'espace des parametres de la population actuelle. Elles illustrent la distorsion inherente dans 2PC et marquent la transition de la premiere phase (pulsars brillants) a la seconde phase (pulsars faibles) d'operation de Fermi. Le developpement des modeles theoriques et un recensement complet de la population galactique des etoiles a neutrons beneficieront de plus de detections de pulsars faibles dans les annees a venir. Certains pulsars γ dans 2PC manifestant de grande efficacite γ sont etudies dans cette these. L'examen des differents parametres qui influencent l'efficacite conduit a quelques candidats pour lesquels un plus grand moment d'inertie est necessaire afin de resoudre le paradoxe de grande efficacite. Les observations de Fermi en rayons γ ont l'air a apporter des contraintes independantes sur le moment d'inertie et les equations d'etat des etoiles a neutrons. (auteur)Original Title
Detections of seven faint γ-ray pulsars and constraints on neutron star moments of inertia with the Fermi-LAT
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18 Dec 2013; 171 p; [260 refs.]; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses; These Docteur, Specialite: astrophysique, plasmas et corpuscules
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