Origin of ultra-high energy cosmic rays in the era of Auger and Telescope ArrayThe origin of ultra-high energy cosmic rays is discussed in light of the latest observational results from the Pierre Auger Observatory, highlighting potential astrophysical sources such as active…Susumu Inoue·Sep 18, 2008SaveLearn
Metallicity in the Galactic Center: The Quintuplet clusterWe present a measurement of metallicity in the Galactic center Quintuplet Cluster made using quantitative spectral analysis of two Luminous Blue Variables (LBVs). The analysis employs line-blanketed…Francisco Najarro, Don F. Figer, D. John Hillier et al.·Sep 18, 2008SaveLearn
The CaT strength in Seyfert nuclei revisited: analyzing young stars and non-stellar light contributions to the spectraIn a former paper (Garcia-Rissmann et al. 2005; hereafter Paper I), we have presented spectra of 64 active, 9 normal and 5 Starburst galaxies in the region around the near-IR Calcium triplet…L. R. Vega, N. V. Asari, R. Cid Fernandes et al.·Sep 18, 2008SaveLearn
The long Galactic bar as seen by UKIDSS Galactic Plane SurveyOver the last decade there have been a series of results supporting the hypothesis of the existence of a long thin bar in the Milky Way with a half-length of 4.5 kpc and a position angle of around 45…A. Cabrera-Lavers, C. Gonzalez-Fernandez, F. Garzon et al.·Sep 18, 2008SaveLearn
Range of stability of solar neutrino flux from the SAGE experiment dataWe study the extent to which the SAGE experiment data indicate the permanence of the solar neutrino flux. It is shown that in the first approximation this flux is constant and its distribution…V. A. Koutvitsky, V. B. Semikoz, D. D. Sokoloff·Sep 18, 2008SaveLearn
A search for iron emission lines in the Chandra X-ray spectra of neutron star low-mass X-ray binariesWhile iron emission lines are well studied in black hole systems, both in X-ray binaries and Active Galactic Nuclei, there has been less of a focus on these lines in neutron star low-mass X-ray…E. M. Cackett, J. M. Miller, J. Homan et al.·Sep 18, 2008SaveLearn
Kink instabilities in jets from rotating magnetic fieldsWe have performed 2.5D and 3D simulations of conical jets driven by the rotation of an ordered, large-scale magnetic field in a stratified atmosphere. The simulations cover about three orders of…R. Moll, H. C. Spruit, M. Obergaulinger·Sep 18, 2008SaveLearn
Secondary Fe-peak nuclei in the Tycho Supernova Remnant: A Promising Tracer of Type Ia Progenitor MetallicityThe Mn to Cr mass ratio in supernova ejecta has recently been proposed as a tracer of Type Ia SN progenitor metallicity. We review the advantages and problems of this observable quantity, and discuss…Carles Badenes, Eduardo Bravo, John P. Hughes·Sep 18, 2008SaveLearn
Cluster Abell 520: a perspective based on member galaxies. A cluster forming at the crossing of three filaments?The connection of cluster mergers with the presence of extended, diffuse radio sources in galaxy clusters is still debated. An interesting case is the rich, merging cluster Abell 520, containing a…M. Girardi, R. Barrena, W. Boschin et al.·Sep 18, 2008SaveLearn
On the axisymmetric thin disk model of flattened galaxiesNon-monotonic features of rotation curves, and also the related gravitational effects typical of thin disks -- like backward-reaction or amplification of rotation by negative surface density…Łukasz Bratek, Joanna Jałocha, Marek Kutschera·Sep 18, 2008SaveLearn
Luminous satellite galaxies in gravitational lensesSubstructures, expected in cold dark matter haloes, have been proposed to explain the anomalous flux ratios in gravitational lenses. About 25% of lenses in the Cosmic Lens All-Sky Survey (CLASS)…S. E. Bryan, S. Mao, S. T. Kay·Sep 18, 2008SaveLearn
Magnetohydrodynamic instability in differentially rotating compressible flowTransport of angular momentum is one of the thrust areas of astrophysical flows. Instabilities and hence the turbulence generated by it has been invoked to understand its role in angular momentum…Mradul Sharma·Sep 18, 2008SaveLearn
A new model for QPOs in accreting black holes: application to the microquasar GRS 1915+105(abridged) In this paper we extend the idea suggested previously by Petri (2005a,b) that the high frequency quasi-periodic oscillations observed in low-mass X-ray binaries may be explained as a…J. Petri·Sep 18, 2008SaveLearn
On the relationship between BL Lacertae objects and radio galaxiesWe present deep radio images at 1.4 GHz of a large and complete sample of BL Lacertae objects (BL Lacs) selected from the Deep X-ray Radio Blazar Survey (DXRBS). We have observed 24 northern sources…Hermine Landt, Hayley E. Bignall·Sep 18, 2008SaveLearn
A large sample of low surface brightness disk galaxies from the SDSS. I: The sample and the stellar populationsWe present the properties of a large sample (12,282) of nearly face-on low surface brightness (LSB) disk galaxies selected from the main galaxy sample of SDSS-DR4. These properties include B-band…G. H. Zhong, Y. C. Liang, F. S. Liu et al.·Sep 18, 2008SaveLearn
Magnetic Field Configuration at the Galactic Center Investigated by Wide Field Near-Infrared PolarimetryWe present a polarimetric map of a 20'x20' area toward the Galactic center. The polarization of point sources has been measured in the J, H, and Ks bands using the near-infrared polarimetric…Shogo Nishiyama, Motohide Tamura, Hirofumi Hatano et al.·Sep 18, 2008SaveLearn
Large-Scale Alignments of Quasar Polarization Vectors: Evidence at Cosmological Scales for Very Light Pseudoscalar Particles Mixing with Photons?Based on a sample of 355 quasars with significant optical polarization, we found that quasar polarization vectors are not randomly oriented over the sky as naturally expected. The probability that…D. Hutsemekers, A. Payez, R. Cabanac et al.·Sep 18, 2008SaveLearn
The Spitzer View of Low-Metallicity Star Formation: II. Mrk 996, a Blue Compact Dwarf Galaxy with an Extremely Dense Nucleus(abridged) We present new Spitzer, UKIRT and MMT observations of the blue compact dwarf galaxy (BCD) Mrk 996, with an oxygen abundance of 12+log(O/H)=8.0. This galaxy has the peculiarity of…T. X. Thuan, L. K. Hunt, Y. I. Izotov·Sep 18, 2008SaveLearn
Luminous Blue Variable Stars In The Two Extremely Metal-Deficient Blue Compact Dwarf Galaxies DDO 68 and PHL 293BWe present photometric and spectroscopic observations of two luminous blue variable (LBV) stars in two extremely metal-deficient blue compact dwarf (BCD) galaxies, DDO 68 with 12+logO/H = 7.15 and…Y. I. Izotov, T. X. Thuan·Sep 18, 2008SaveLearn
AKARI Near Infrared Spectroscopy: Detection of H2O and CO2 Ices toward Young Stellar Objects in the Large Magellanic CloudWe present the first results of AKARI Infrared Camera near-infrared spec- troscopic survey of the Large Magellanic Cloud (LMC). We detected absorption features of the H2O ice 3.05 um and the CO2 ice…Takashi Shimonishi, Takashi Onaka, Daisuke Kato et al.·Sep 18, 2008SaveLearn
Global Disk Oscillations in Binary Be StarsWe study the effects of the tidal interaction with the companion, via orbital separation and binary mass ratio, on the global one-armed oscillation modes in disks around binary Be stars. Our model…Finny Oktariani, Atsuo T. Okazaki·Sep 18, 2008SaveLearn
Some Enigmatic Aspects of the Early Universe IIIIn the previous parts of the discussion on the same topic, various aspects of the very early universe were discussed. We discussed how inclusion of large dark energy term compensates for the net…C Sivaram, Kenath Arun·Sep 18, 2008SaveLearn
On the acceleration of Ultra-High-Energy Cosmic RaysUltra High Energy Cosmic Rays (UHECRs) hit the Earth's atmosphere with energies exceeding 1018 eV. This is the same energy as carried by a tennis ball moving at 100 km/h, but concentrated on…Federico Fraschetti·Sep 18, 2008SaveLearn
Simultaneous Triggered Collapse of the Presolar Dense Cloud Core and Injection of Short-Lived Radioisotopes by a Supernova Shock WaveCosmochemical evidence for the existence of short-lived radioisotopes (SLRI) such as 26Al and 60Fe at the time of the formation of primitive meteorites requires that these isotopes were…Alan P. Boss, Sergei I. Ipatov, Sandra A. Keiser et al.·Sep 18, 2008SaveLearn
The Growth of Central and Satellite Galaxies in Cosmological Smoothed Particle Hydrodynamics SimulationsWe examine the accretion and merger histories of central and satellite galaxies in a smoothed particle hydrodynamics (SPH) cosmological simulation that resolves galaxies down to 7e9 M[Sun]. Most…Vimal Simha, David H. Weinberg, Romeel Dave et al.·Sep 18, 2008SaveLearn