Kavli Affiliate: Peter Michelson | Summary:We report on spectroscopic observations covering most of the 475 BL Lacs in the 2nd Fermi LAT catalog of AGN. Including archival measurements (correcting several erroneous literature values) we now have spectroscopic redshifts for 44% of the BL Lacs. We establish firm lower redshift limits via intervening absorption systems and […]
Kavli Affiliate: Ralf Kaehler | Summary:Structured Adaptive Mesh Refinement (SAMR) is a popular numerical technique to study processes with high spatial and temporal dynamic range. It reduces computational requirements by adapting the lattice on which the underlying differential equations are solved to most efficiently represent the solution. Particularly in astrophysics and cosmology such simulations now […]
Kavli Affiliate: Ralf Kaehler | Summary:Recently, we have shown how current cosmological N-body codes already follow the fine grained phase-space information of the dark matter fluid. Using a tetrahedral tesselation of the three-dimensional manifold that describes perfectly cold fluids in six-dimensional phase space, the phase-space distribution function can be followed throughout the simulation. This allows […]
Kavli Affiliate: Ralf Kaehler | Summary:In the last decades cosmological N-body dark matter simulations have enabled ab initio studies of the formation of structure in the Universe. Gravity amplified small density fluctuations generated shortly after the Big Bang, leading to the formation of galaxies in the cosmic web. These calculations have led to a growing […]
Kavli Affiliate: Concetta Cartaro | Summary:Data from high-energy physics (HEP) experiments are collected with significant financial and human effort and are mostly unique. An inter-experimental study group on HEP data preservation and long-term analysis was convened as a panel of the International Committee for Future Accelerators (ICFA). The group was formed by large collider-based experiments […]
Kavli Affiliate: Peter Michelson | Summary:We report on optical spectroscopy of 165 Flat Spectrum Radio Quasars (FSRQs) in the Fermi 1LAC sample, which have helped allow a nearly complete study of this population. Fermi FSRQ show significant evidence for non-thermal emission even in the optical; the degree depends on the gamma-ray hardness. They also have […]
Kavli Affiliate: Ralf Kaehler | Summary:The primordial velocity dispersion of dark matter is small compared to the velocities attained during structure formation. The initial density distribution is close to uniform and it occupies an initial sheet in phase space that is single valued in velocity space. Because of gravitational forces this three dimensional manifold evolves […]
Kavli Affiliate: Peter Michelson | Summary:The Fermi Gamma-ray Space Telescope (Fermi) was launched on June 11, 2008 and began its first year sky survey on August 11, 2008. The Large Area Telescope (LAT), a wide field-of-view pair-conversion telescope covering the energy range from 20 MeV to more than 300 GeV, is the primary instrument on […]
Kavli Affiliate: Richard Dubois | Summary:The past decade has presented a revolution in the field of observational high energy gamma-ray astrophysics with the advent of a new generation in ground-based TeV telescopes and subsequent GeV space telescopes. The Fermi Large Area Telescope (LAT) was launched in August 2008 and has offered unprecedented sensitivity and survey […]
Kavli Affiliate: Peter Michelson | Summary:GALPROP is a numerical code for calculating the galactic propagation of relativistic charged particles and the diffuse emissions produced during their propagation. The code incorporates as much realistic astrophysical input as possible together with latest theoretical developments and has become a de facto standard in astrophysics of cosmic rays. We […]