Extremely metal-poor star-forming galaxies. New detections and general morphological and photometric properties(abridged) We present long-slit spectroscopy with the 3.6m ESO telescope of eight HII regions in seven star-forming (SF) dwarf galaxies, discovered in SDSS DR4 and 6dFGRS. In addition, we use SDSS…P. Papaderos, N. G. Guseva, Y. I. Izotov et al.·Sep 7, 2008SaveLearn
Inflationary Axion Cosmology Beyond Our HorizonIn theories of axion dark matter with large axion decay constant, temperature variations in the CMB are extremely sensitive to perturbations in the initial axion field, allowing one to place a lower…David B. Kaplan, Ann E. Nelson·Sep 7, 2008SaveLearn
The stellar content of the Hamburg/ESO survey. V. The metallicity distribution function of the Galactic haloWe determine the metallicity distribution function (MDF) of the Galactic halo by means of a sample of 1638 metal-poor stars selected from the Hamburg/ESO objective-prism survey (HES). The sample was…T. Schoerck, N. Christlieb, J. G. Cohen et al.·Sep 6, 2008SaveLearn
The history of star formation and mass assembly in early-type galaxiesWe define a volume limited sample of over 14,000 early-type galaxies (ETGs) selected from data release six of the Sloan Digital Sky Survey. The density of environment of each galaxy is robustly…M. S. Clemens, A. Bressan, B. Nikolic et al.·Sep 6, 2008SaveLearn
Application of a New Non-Linear Least Squares Velocity Curve Analysis Technique for Spectroscopic Binary StarsUsing measured radial velocity data of nine double lined spectroscopic binary systems NSV 223, AB And, V2082 Cyg, HS Her, V918 Her, BV Dra, BW Dra, V2357 Oph, and YZ Cas, we find corresponding…K. Karami, R. Mohebi, M. M. Soltanzadeh·Sep 6, 2008SaveLearn
AE Aquarii: The first white dwarf in the family of spin-powered pulsarsSimulation of Doppler H-alpha tomogram of the nova-like star AE Aquarii suggests that the dipole magnetic moment of the white dwarf is close to 1.5E+34 G cm3. This is consistent with the lower limit…N. R. Ikhsanov, N. G. Beskrovnaya·Sep 6, 2008SaveLearn
Do submillimeter galaxies really trace the most massive dark matter halos? Discovery of a high-z cluster in a highly active phase of evolutionWe present detailed observations of a z~1.99 cluster of submillimeter galaxies (SMGs), discovered as the strongest redshift spike in our entire survey of ~100 SMGs across 800 square arcmin. It is the…S. C. Chapman, A. W. Blain, R. Ibata et al.·Sep 6, 2008SaveLearn
Coronal Alfven speeds in an isothermal atmosphere I. Global propertiesEstimating Alfven speeds is of interest in modelling the solar corona, studying the coronal heating problem and understanding the initiation and propagation of coronal mass ejections (CMEs). We…S. Regnier, E. R. Priest, A. W. Hood·Sep 6, 2008SaveLearn
Supermassive Black Holes in Galactic BulgesGrowing evidence indicate supermassive black holes (SMBHs) in a mass range of M BH 106-1010M lurking in central stellar bulges of galaxies.Extensive observations reveal…Yu-Qing Lou, Yan-Fei Jiang·Sep 6, 2008SaveLearn
Geometrical and Physical Properties of Circumbinary Discs in Eccentric Stellar BinariesIn a previous work (Pichardo et al. 2005), we studied stable configurations for circumstellar discs in eccentric binary systems. We searched for "invariant loops": closed curves (analogous to…Barbara Pichardo, Linda S. Sparke, Luis A. Aguilar·Sep 6, 2008SaveLearn
Extended Emission-Line Regions: Remnants of Quasar Superwinds?We give an overview of our recent integral-field-unit spectroscopy of luminous extended emission-line regions (EELRs) around low-redshift quasars, including new observations of 5 fields. Previous…Hai Fu, Alan Stockton·Sep 6, 2008SaveLearn
A vortex model for rotating compact objectsA rotating stationary solution of the vacuum Einstein equations with a cosmological constant is exhibited which reduces to de Sitter's interior cosmological solution when the angular momentum…G. F. Chapline, P. Marecki·Sep 5, 2008SaveLearn
Destruction of Molecular Gas Reservoirs in Early-Type Galaxies by Active Galactic Nucleus FeedbackResidual star formation at late times in early-type galaxies and their progenitors must be suppressed in order to explain the population of red, passively evolving systems we see today. Likewise,…Kevin Schawinski, Chris J. Lintott, Daniel Thomas et al.·Sep 5, 2008SaveLearn
Low Rv from circumstellar dust around supernovaeThe effective extinction law for supernovae surrounded by circumstellar dust is examined by Monte-Carlo simulations. Grains with light scattering properties as for interstellar dust in the Milky-Way…Ariel Goobar·Sep 5, 2008SaveLearn
Spectrophotometry with Hectospec, the MMT's Fiber-Fed SpectrographWe describe techniques for photometric calibration of optical spectra obtained with the MMT's fiber-fed spectrograph, Hectospec. The atmospheric dispersion compensation prisms built into the…Daniel G. Fabricant, Michael J. Kurtz, Margaret J. Geller et al.·Sep 5, 2008SaveLearn
Intrinsic photometric characterisation of stellar oscillations and granulation. Solar reference values and CoRoT response functionsContext: Measuring amplitudes of solar-like oscillations and the granulation power spectral density constitute two promising sources of information to improve our understanding and description of the…E. Michel, R. Samadi, F. Baudin et al.·Sep 5, 2008SaveLearn
iVINE - Ionization in the parallel tree/SPH code VINE: First results on the observed age-spread around O-starsWe present a three-dimensional, fully parallelized, efficient implementation of ionizing UV radiation for smoothed particle hydrodynamics (SPH) including self-gravity. Our method is based on the…M. Gritschneder, T. Naab, A. Burkert et al.·Sep 5, 2008SaveLearn
Statistical anisotropy of the curvature perturbation from vector field perturbationsThe δN formula for the primordial curvature perturbation ζis extended to include vector as well as scalar fields. Formulas for the tree-level contributions to the spectrum and bispectrum of ζare…Konstantinos Dimopoulos, Mindaugas Karciauskas, David H. Lyth et al.·Sep 5, 2008SaveLearn
Gravitational radiospectrometerGravitational lensing is predicted by general relativity and is found in observations. When a gravitating body is surrounded by a plasma, the lensing angle depends on a frequency of the…G. S. Bisnovatyi-Kogan, O. Yu. Tsupko·Sep 5, 2008SaveLearn
Coupling from the photosphere to the chromosphere and the coronaThe atmosphere of the Sun is characterized by a complex interplay of competing physical processes: convection, radiation, conduction, and magnetic fields. The most obvious imprint of the solar…S. Wedemeyer-Böhm, A. Lagg, Å. Nordlund·Sep 5, 2008SaveLearn
Galactic Halos Derived from LambdaCDM Cosmology Simulation and their Red-Shift EvolutionGalaxies can form in a sufficiently deep gravitational potential so that efficient gas cooling occurs. We estimate that such potential is provided by a halo of mass $M Mc ≈ 7.0 ×…Hung-Yu Jian, Chia-Hung Chien, Tzihong Chiueh·Sep 5, 2008SaveLearn
The Properties of Sub-mm Galaxies in Hierarchical ModelsWe use the combined GALFORM semi-analytical model of galaxy formation and GRASIL spectrophotometric code to investigate the properties of galaxies selected via their sub-mm emission. Our fiducial…Mark Swinbank, Cedric Lacey, Ian Smail et al.·Sep 5, 2008SaveLearn
On the Brightening Propagation of Post-Flare Loops Observed by TRACEExamining flare data observed by TRACE satellite from May 1998 to December 2006, we choose 190 (151 M-class and 39 X-class) flare events which display post-flare loops (PFLs), observed by 171 Åand…Leping Li, Jun Zhang·Sep 5, 2008SaveLearn
The Mid-Infrared Extinction Law in the Ophiuchus, Perseus, and Serpens Molecular CloudsWe compute the mid-infrared extinction law from 3.6-24 microns in three molecular clouds: Ophiuchus, Perseus, and Serpens, by combining data from the "Cores to Disks" Spitzer Legacy Science…Nicholas L. Chapman, Lee G. Mundy, Shih-Ping Lai et al.·Sep 5, 2008SaveLearn
A Catalog of X-ray Point Sources from Two Megaseconds of Chandra Observations of the Galactic CenterWe present a catalog of 9017 X-ray sources identified in Chandra observations of a 2 by 0.8 degree field around the Galactic center. We increase the number of known X-ray sources in the region by a…M. P. Muno, F. E. Bauer, F. K. Baganoff et al.·Sep 5, 2008SaveLearn