Stability of the directly imaged multiplanet system HR 8799: resonance and massesA new era of directly imaged extrasolar planets has produced a three-planet system (Marois et al. 2008), where the masses of the planets have been estimated by untested cooling models. We point out…Daniel C. Fabrycky, Ruth A. Murray-Clay·Dec 1, 2008SaveLearn
Clues from the prompt emission of GRB 080319BThe extremely bright optical flash that accompanied GRB 080319B suggested, at first glance, that the prompt γ-rays in this burst were produced by Synchrotron self Compton (SSC). We analyze here the…Y. C. Zou, T. Piran, R. Sari·Dec 1, 2008SaveLearn
Cosmic rays and the magnetic field in the nearby starburst galaxy NGC 253 I. The distribution and transport of cosmic raysThe diffusive and convective CR transport in NGC 253 from the disk into the halo is investigated using the local CR bulk speed. The connection between the CR transport and the galactic wind is…V. Heesen, R. Beck, M. Krause et al.·Dec 1, 2008SaveLearn
Lyman-alpha constraints on warm and on warm-plus-cold dark matter modelsWe revisit Lyman-alpha bounds on the dark matter mass in Lambda Warm Dark Matter (Lambda-WDM) models, and derive new bounds in the case of mixed Cold plus Warm models (Lambda-CWDM), using a set up…Alexey Boyarsky, Julien Lesgourgues, Oleg Ruchayskiy et al.·Dec 1, 2008SaveLearn
A step towards testing general relativity using weak gravitational lensing and redshift surveysUsing the linear theory of perturbations in General Relativity, we express a set of consistency relations that can be observationally tested with current and future large scale structure surveys. We…Yong-Seon Song, Olivier Doré·Dec 1, 2008SaveLearn
15 GHz VLBI detection of the HST-1 feature in the M87 jetA bright feature 100 pc away from the core in the powerful jet of M 87 shows mysterious properties. Earlier radio, optical and X-ray observations have shown that this feature, labelled HST-1, is…C. S. Chang, E. Ros, Y. Y. Kovalev et al.·Dec 1, 2008SaveLearn
Anisotropic non-Gaussianity from vector field perturbationsWe suppose that a vector field perturbation causes part of the primordial curvature perturbation. The non-Gaussianity parameter fNL is then, in general, statistically anisotropic. We calculate its…Mindaugas Karciauskas, Konstantinos Dimopoulos, David H. Lyth·Dec 1, 2008SaveLearn
Neutron Stars as a Probe for Dense MatterWe study different stages of the neutron star cooling by computing neutron star properties at various temperatures and entropies using an effective chiral model including hadronic and quark degrees…V. Dexheimer, S. Schramm·Dec 1, 2008SaveLearn
Spherical Collapse and Cluster Counts in Modified Gravity ModelsModifications to the gravitational potential affect the nonlinear gravitational evolution of large scale structures in the Universe. To illustrate some generic features of such changes, we study the…Matthew C. Martino, Hans F. Stabenau, Ravi K. Sheth·Dec 1, 2008SaveLearn
The Calibration of Stromgren uvby-Hbeta Photometry for Late-Type Stars -- a Model Atmosphere ApproachWe aim to test the power of theoretical calibrations based on a new generation of MARCS models by comparisons with observational photomteric data. We calculate synthetic uvby-Hbeta colour indices…A. Önehag, B. Gustafsson, K. Eriksson et al.·Dec 1, 2008SaveLearn
Measuring dark energy spatial inhomogeneity with supernova dataThe gravitational lensing distortion of distant sources by the large-scale distribution of matter in the Universe has been extensively studied. In contrast, very little is known about the effects due…Asantha Cooray, Daniel E. Holz, Robert Caldwell·Dec 1, 2008SaveLearn
Like vs. Like: Strategy and Improvements in Supernova Cosmology SystematicsControl of systematic uncertainties in the use of Type Ia supernovae as standardized distance indicators can be achieved through contrasting subsets of observationally-characterized, like supernovae.…Eric V. Linder·Dec 1, 2008SaveLearn
On the Time Variability of Geometrically-Thin Black Hole Accretion Disks II: Viscosity-Induced Global Oscillation Modes in Simulated DisksWe examine the evolution and influence of viscosity-induced diskoseismic modes in simulated black hole accretion disks. Understanding the origin and behavior of such oscillations will help us to…Sean M. O'Neill, Christopher S. Reynolds, M. Coleman Miller·Dec 1, 2008SaveLearn
Young L Dwarfs Identified in the Field: A Preliminary Low-Gravity, Optical Spectral Sequence from L0 to L5We present an analysis of 23 L dwarfs whose optical spectra display unusual features. Twenty-one were uncovered during our search for nearby, late-type objects using the Two Micron All-Sky Survey…Kelle L. Cruz, J. Davy Kirkpatrick, Adam J. Burgasser·Dec 1, 2008SaveLearn
Diagnoses to unravel secular hydrodynamical processes in rotating main sequence stars(Abridged) We present a detailed analysis of the main physical processes responsible for the transport of angular momentum and chemical species in the radiative regions of rotating stars. We focus on…T. Decressin, S. Mathis, A. Palacios et al.·Dec 1, 2008SaveLearn
Utilizing Type Ia Supernovae in a Large, Fast, Imaging Survey to Constrain Dark EnergyWe study the utility of a large sample of type Ia supernovae that might be observed in an imaging survey that rapidly scans a large fraction of the sky for constraining dark energy. We consider…Andrew R. Zentner, Suman Bhattacharya·Dec 1, 2008SaveLearn
On-sky wide field adaptive optics correction using multiple laser guide stars at the MMTWe describe results from the first astronomical adaptive optics system to use multiple laser guide stars, located at the 6.5-m MMT telescope in Arizona. Its initial operational mode, ground-layer…Christoph Baranec, Michael Hart, N. Mark Milton et al.·Dec 1, 2008SaveLearn
Forward Shock Proper Motions of Kepler's Supernova RemnantThe X-ray structure of Kepler's supernova remnant shows a rounded shape delineated by forward shocks. We measure proper motions of the forward shocks on overall rims of the remnant, by using…Satoru Katsuda, Hiroshi Tsunemi, Hiroyuki Uchida et al.·Dec 1, 2008SaveLearn
Stability window and mass-radius relation for magnetized strange quark starsThe stability of magnetized strange quark matter (MSQM) is investigated within the phenomenological MIT bag model, taking into account the variation of the relevant input parameters, namely, the…R. Gonzalez Felipe, A. Perez Martinez·Dec 1, 2008SaveLearn
The Impact of Simulations in Cosmology and Galaxy Formation A summary of the Workshop NOVICOSMO 2008In the study of the process of cosmic structure formation numerical simulations are crucial tools to interface observational data to theoretical models and to investigate issues otherwise unexplored.…Paolo Salucci, Stefano Borgani, Carlos Frenk et al.·Dec 1, 2008SaveLearn
Giants in the globular cluster omega Centauri: dust production, mass loss and distanceWe present spectral energy distribution modelling of 6875 stars in omega Centauri, obtaining stellar luminosities and temperatures by fitting literature photometry to state-of-the-art MARCS stellar…Iain McDonald, Jacco Th. van Loon, Leen Decin et al.·Dec 1, 2008SaveLearn
Energy Spectra of Elemental Groups of Cosmic Rays: Update on the KASCADE Unfolding AnalysisThe KASCADE experiment measures extensive air showers induced by cosmic rays in the energy range around the so-called knee. The data of KASCADE have been used in a composition analysis showing the…KASCADE Collaboration, W. D. Apel·Dec 1, 2008SaveLearn
Multi-wavelength observations and modelling of a canonical solar flareThis paper investigates the temporal evolution of temperature, emission measure, energy loss and velocity in a C-class solar flare from both an observational and theoretical perspective. The…Claire L. Raftery, Peter T. Gallagher, Ryan O. Milligan et al.·Dec 1, 2008SaveLearn
Spectropolarimetric Variability and Co-Rotating Structure in HD 92207We report on low resolution (R~3000) spectropolarimetry of the A0 supergiant star HD 92207. This star is well-known for significant spectral variability. The source was observed on seven different…R Ignace, S Hubrig, M Scholler·Dec 1, 2008SaveLearn
Neutrino signal from gamma-ray loud binaries powered by high energy protonsWe present a hadronic model of activity for Galactic gamma-ray-loud binaries, in which the multi-TeV neutrino flux from the source can be much higher and/or harder than the detected TeV gamma-ray…A. Neronov, M. Ribordy·Dec 1, 2008SaveLearn