Search Publications
Temporal Power Spectra of the Horizontal Velocity of the Solar Photosphere
Matsumoto, Takuma; Kitai, Reizaburo
We have derived the temporal power spectra of the horizontal velocity of the solar photosphere. The data sets for 14 quiet regions observed with the G-band filter of Hinode/SOT are analyzed to measure the temporal fluctuation of the horizontal velocity by using the local correlation tracking (LCT) method. Among the high resolution (~0farcs2) and s…
Dust in the Diffuse Emission of the Galactic Plane: The Herschel/Spitzer Spectral Energy Distribution Fitting
Bernard, J. -P.; Martin, P. G.; Paladini, R. +4 more
The first Herschel Hi-Gal images of the Galactic plane unveil the far-infrared diffuse emission of the interstellar medium with an unprecedented angular resolution and sensitivity. In this Letter, we present the first analysis of these data in combination with those of Spitzer GLIMPSE and MIPSGAL. We selected a relatively diffuse and low excitatio…
X-ray Emission from the Binary Central Stars of the Planetary Nebulae HFG 1, DS 1, and LoTr 5
De Marco, Orsola; Kastner, Joel H.; Chu, You-Hua +1 more
Close binary systems undergoing mass transfer or common envelope interactions can account for the morphological properties of some planetary nebulae. The search for close binary companions in planetary nebulae is hindered by the difficulty of detecting cool, late-type, main-sequence companions in binary systems with hot pre-white-dwarf primaries. …
Late-time Observations of GRB 080319B: Jet Break, Host Galaxy, and Accompanying Supernova
Kouveliotou, C.; Fruchter, A. S.; Rol, E. +15 more
The Swift-discovered GRB 080319B was by far the most distant source ever observed at naked-eye brightness, reaching a peak apparent magnitude of 5.3 at a redshift of z = 0.937. We present our late-time optical (Hubble Space Telescope, Gemini, and Very Large Telescope) and X-ray (Chandra) observations, which confirm that an achromatic break occurre…
The 1.6 µm Near-infrared Nuclei of 3C Radio Galaxies: Jets, Thermal Emission, or Scattered Light?
Baum, Stefi A.; O'Dea, Christopher P.; Axon, David J. +6 more
Using HST NICMOS 2 observations we have measured 1.6 µm near-infrared nuclear luminosities of 100 3CR radio galaxies with z < 0.3, by modeling and subtracting the extended emission from the host galaxy. We performed a multiwavelength statistical analysis (including optical and radio data) of the properties of the nuclei following classifi…
The X-ray Spectra of the Luminous LMXBs in NGC 3379: Field and Globular Cluster Sources
Zezas, A.; Gallagher, J.; King, A. R. +10 more
From a deep multi-epoch Chandra observation of the elliptical galaxy NGC 3379 we report the spectral properties of eight luminous LMXBs (L X >1.2 × 1038 erg s-1). We also present a set of spectral simulations, produced to aid the interpretation of low-count single-component spectral modeling. These simulations d…
O VI Absorbers Tracing Hot Gas Associated with a Pair of Galaxies at z = 0.167
Savage, B. D.; Narayanan, A.; Wakker, B. P. +6 more
High signal-to-noise observations of the QSO PKS 0405-123 (z em = 0.572) with the Cosmic Origins Spectrograph from 1134 to 1796 Å with a resolution of ~17 km s-1 are used to study the multi-phase partial Lyman limit system (LLS) at z = 0.16716, which has previously been studied using relatively low signal-to-noise spectra fro…
Physical Characteristics and Non-Keplerian Orbital Motion of "Propeller" Moons Embedded in Saturn's Rings
Porco, Carolyn C.; Hedman, Matthew M.; Burns, Joseph A. +8 more
We report the discovery of several large "propeller" moons in the outer part of Saturn's A ring, objects large enough to be followed over the 5 year duration of the Cassini mission. These are the first objects ever discovered that can be tracked as individual moons, but do not orbit in empty space. We infer sizes up to 1-2 km for the unseen moonle…
X-ray, FUV, and UV Observations of α Centauri B: Determination of Long-term Magnetic Activity Cycle and Rotation Period
Guinan, E. F.; DeWarf, L. E.; Datin, K. M.
Over the last couple of decades we have been carrying out a study of stellar magnetic activity, dynamos, atmospheric physics, and spectral irradiances from a sample of solar-type G0-5 V stars with different ages. One of the major goals of this program is to study the evolution of the Sun's X-ray through NUV spectral irradiances with age. Of partic…
The Origin and Evolution of the Halo PN BoBn 1: From a Viewpoint of Chemical Abundances Based on Multiwavelength Spectra
Izumiura, Hideyuki; Otsuka, Masaaki; Hyung, Siek +1 more
We have performed a comprehensive chemical abundance analysis of the extremely metal-poor ([Ar/H] < -2) halo planetary nebula (PN) BoBn 1 based on International Ultraviolet Explorer archive data, Subaru/High-Dispersion Spectrograph spectra, VLT/UVES archive data, and Spitzer/IRS spectra. We have detected over 600 lines in total and calculated i…