Fresnel interferometric arrays for space-based imaging: testbed resultsThis paper presents the results of a Fresnel Interferometric Array testbed. This new concept of imager involves diffraction focussing by a thin foil, in which many thousands of punched subapertures…Denis Serre, Laurent Koechlin, Paul Deba·Aug 5, 2008SaveLearn
Shock Waves in Eulerian Cosmological Simulations: Main Properties and Acceleration of Cosmic RaysWe analyze the properties of Large Scale Shocks in a cosmological volume of size 103Mpc/h simulated with the public 1.0.1 release of the ENZO code. Different methods to identify and characterize…F. Vazza, G. Brunetti, C. Gheller·Aug 5, 2008SaveLearn
Magnetized GRB outflow model: weak reverse shock emission and short energy transfer timescaleWe show that the absence of the bright optical flashes in most Swift Gamma-ray Burst (GRB) afterglows can be explained, if the reverse shock region is magnetized with a σ 1, or the…Yi-Zhong Fan·Aug 5, 2008SaveLearn
The Density Probability Distribution in Compressible Isothermal Turbulence: Solenoidal versus Compressive ForcingThe probability density function (PDF) of the gas density in turbulent supersonic flows is investigated with high-resolution numerical simulations. In a systematic study, we compare the density…Christoph Federrath, Ralf S. Klessen, Wolfram Schmidt·Aug 5, 2008SaveLearn
Cold streams in early massive hot haloes as the main mode of galaxy formationThe massive galaxies in the young universe, ten billion years ago, formed stars at surprising intensities. Although this is commonly attributed to violent mergers, the properties of many of these…A. Dekel, Y. Birnboim, G. Engel et al.·Aug 5, 2008SaveLearn
Galaxy Groups in the SDSS DR4: III. the luminosity and stellar mass functionsUsing a large galaxy group catalogue constructed from the Sloan Digital Sky Survey Data Release 4 (SDSS DR4) with an adaptive halo-based group finder, we investigate the luminosity and stellar mass…Xiaohu Yang, H. J. Mo, Frank C. van den Bosch·Aug 5, 2008SaveLearn
SDSS J120923.7+264047: A new massive galaxy cluster with a bright giant arcHighly magnified lensed galaxies allow us to probe the morphological and spectroscopic properties of high-redshift stellar systems in great detail. However, such objects are rare, and there are only…Eran O. Ofek, Stella Seitz, Felix Klein·Aug 5, 2008SaveLearn
Bulge Formation by the Coalescence of Giant Clumps in Primordial Disk GalaxiesGas-rich disks in the early universe are highly turbulent and have giant star-forming clumps. Models suggest the clumps form by gravitational instabilities, and if they resist disruption by star…Bruce G. Elmegreen, Frederic Bournaud, Debra Meloy Elmegreen·Aug 5, 2008SaveLearn
Determining the extragalactic extinction law with SALTWe present CCD imaging observations of early-type galaxies with dark lanes obtained with the Southern African Large Telescope (SALT) during its performance-verification phase. We derive the…Ido Finkelman, Noah Brosch, Alexei Y. Kniazev et al.·Aug 5, 2008SaveLearn
Effective theory for the cosmological generation of structureThe current understanding of structure formation in the early universe is mainly built on a magnification of quantum fluctuations in an initial vacuum state during an early phase of accelerated…Martin Bojowald, Aureliano Skirzewski·Aug 5, 2008SaveLearn
Identification of different types of kink modes in coronal loops: principles and application to TRACE resultsWe explore the possible observational signatures of different types of kink modes (horizontal and vertical oscillations in their fundamental mode and second harmonic) that may arise in coronal loops,…T. J. Wang, S. K. Solanki, M. Selwa·Aug 5, 2008SaveLearn
Pseudoscalar perturbations and polarization of the cosmic microwave backgroundWe show that models of new particle physics containing massless pseudoscalar fields super-weakly coupled to photons can be very efficiently probed with CMB polarization anisotropies. The stochastic…Maxim Pospelov, Adam Ritz, Constantinos Skordis·Aug 5, 2008SaveLearn
Turbulent AGN toriRecently, the MID-infrared Interferometric instrument (MIDI) at the VLTI has shown that dust tori in the two nearby Seyfert galaxies NGC 1068 and the Circinus galaxy are geometrically thick and can…M. Schartmann, K. Meisenheimer, H. Klahr et al.·Aug 5, 2008SaveLearn
Distance to VY Canis Majoris with VERAWe report astrometric observations of H2O masers around the red supergiant VY Canis Majoris (VY CMa) carried out with VLBI Exploration of Radio Astrometry (VERA). Based on astrometric monitoring for…Yoon Kyung Choi, Tomoya Hirota, Mareki Honma et al.·Aug 5, 2008SaveLearn
On the origin of radio emission in radio quiet quasarsThe radio emission in radio loud quasars originates in a jet carrying relativistic electrons. In radio quiet quasars (RQQs) the relative radio emission is ~103 times weaker, and its origin is not…Ari Laor, Ehud Behar·Aug 5, 2008SaveLearn
Probing dust grain evolution in IM Lupi's circumstellar disc. Multi-wavelength observations and modelling of the dust discWe present a panchromatic study, involving a multiple technique approach, of the circumstellar disc surrounding the T Tauri star IM Lupi (Sz 82). We have undertaken a comprehensive observational…C. Pinte, D. L. Padgett, F. Menard et al.·Aug 5, 2008SaveLearn
T Tauri Jet Physics Resolved Near The Launching Region with the Hubble Space TelescopeWe present an analysis of the gas physics at the base of jets from five T Tauri stars based on high angular resolution optical spectra, using the Hubble Space Telescope Imaging Spectrograph…Deirdre Coffey, Francesca Bacciotti, Linda Podio·Aug 5, 2008SaveLearn
Open questions in the study of population III star formationThe first stars were key drivers of early cosmic evolution. We review the main physical elements of the current consensus view, positing that the first stars were predominantly very massive. We…S. C. O. Glover, P. C. Clark, T. H. Greif et al.·Aug 5, 2008SaveLearn
A 3D radiative transfer framework: III. periodic boundary conditionsWe present a general method to solve radiative transfer problems including scattering in the continuum as well as in lines in 3D configurations with periodic boundary conditions. he scattering…Peter H. Hauschildt, E. Baron·Aug 5, 2008SaveLearn
The Luminosity Function of Long Gamma-Ray Bursts and their rate at z>6We compute the luminosity function (LF) and the formation rate of long gamma ray bursts (GRBs) in three different scenarios: i) GRBs follow the cosmic star formation and their LF is constant in time;…R. Salvaterra, S. Campana, G. Chincarini et al.·Aug 5, 2008SaveLearn
On spatial variations of the electron-to-proton mass ratio in the Milky Way(Abridged) Radio-astronomical observations of molecular cores in lines of NH3 (J,K)=(1,1), CCS JN=21-10, HC3N J=5-4, and N2H+ J=1-0 are used to measure the relative radial velocity offsets, Delta…S. A. Levshakov, P. Molaro, M. G. Kozlov·Aug 5, 2008SaveLearn
Discovery of the Inner Ring around PSR B1509-58A Chandra study of pulsar wind nebula around the young energetic pulsar PSR B1509-58 is presented. The high resolution X-ray image with total exposure time of 190 ks reveals a ring like feature…Yoichi Yatsu, Nobuyuki Kawai, Shinpei Shibata et al.·Aug 5, 2008SaveLearn
Stratorotational instability in MHD Taylor-Couette flowsThe stability of dissipative Taylor-Couette flows with an axial stable density stratification and a prescribed azimuthal magnetic field is considered. Global nonaxisymmetric solutions of the…G. Ruediger, D. A. Shalybkov·Aug 5, 2008SaveLearn
Hot Subdwarfs in Binaries as the Source of the Far-UV Excess in Elliptical GalaxiesThe excess of far-ultraviolet (far-UV) radiation in elliptical galaxies has remained one of their most enduring puzzles. In contrast, the origin of old blue stars in the Milky Way, hot subdwarfs, is…Philipp Podsiadlowski, Zhanwen Han, Anthony E. Lynas-Gray et al.·Aug 5, 2008SaveLearn
The Connection between Orbits and Isophotal Shape in Elliptical GalaxiesWe examine the origin of photometrical properties of N-body merger remnants from the perpective of their orbital content. We show that disc mergers alone are unlikely to form a boxy-discy dichotomy…Roland Jesseit, Thorsten Naab, Andreas Burkert·Aug 5, 2008SaveLearn