Angular Anisotropies in the Cosmic Gamma-Ray Background as a Probe of Its Origin
The Astrophysical Journal American Astronomical Society 667:1 (2007) l1-l4
A modified higher order Godunov’s scheme for stiff source conservative hydrodynamics
Journal of Computational Physics Elsevier 224:2 (2007) 519-538
Ultrahigh energy cosmic rays as heavy nuclei from cluster accretion shocks
Proceedings of the 30th International Cosmic Ray Conference, ICRC 2007 4:HE PART 1 (2007) 555-558
Abstract:
Large-scale accretion shocks around massive clusters of galaxies, generically expected in hierarchical scenarios of cosmological structure formation, are shown to be plausible sources of the observed ultrahigh energy cosmic rays (UHECRs) by accelerating a mixture of heavy nuclei including the iron group elements. Current observations can be explained if the source composition at injection for the heavier nuclei is somewhat enhanced from simple expectations for the accreting gas. The proposed picture should be clearly testable by current and upcoming facilities in the near future through characteristic features in the UHECR spectrum, composition and anisotropy, in particular the rapid increase of the average mass composition with energy from 1019 to 1020 eV. The associated X-ray and gamma-ray signatures are also briefly discussed.A Puzzling Merger in A3266: The Hydrodynamic Picture from XMM-Newton
The Astrophysical Journal American Astronomical Society 643:2 (2006) 790-796
Deeper Chandra Follow-up of Cygnus TeV Source Perpetuates Mystery
The Astrophysical Journal American Astronomical Society 643:1 (2006) 238-244