Search Publications
Morphological study of penumbral formation
Kitai, Reizaburo; Watanabe, Hiroko; Otsuji, Ken'ichi
Penumbrae are known to be areas of mainly horizontal magnetic field surrounding umbrae of relatively large and mature sunspots. In this paper, we observationally studied the formation of penumbrae in NOAA 10978, where several penumbral formations were observed in G-band images of the Solar Optical Telescope on board Hinode. Thanks to the continuou…
GALAPAGOS-C: analysis of galaxy morphologies using high-performance computing methods
Kelvin, Lee S.; Barden, Marco; Häußler, Boris +2 more
We present GALAPAGOS-C, a code designed to process a complete set of survey images through automation of source detection (via SEXTRACTOR), postage stamp cutting, object mask preparation, sky background estimation and complex two-dimensional light profile Sérsic modelling (via GALFIT). GALAPAGOS-C is designed around the concept of MPI-parallelizat…
The ultraviolet radiation environment in the habitable zones around low-mass exoplanet host stars
Loyd, R. O. Parke; France, Kevin; Linsky, Jeffrey L.
The EUV (200–911 Å), FUV (912–1750 Å), and NUV (1750–3200 Å) spectral energy distribution of exoplanet host stars has a profound influence on the atmospheres of Earth-like planets in the habitable zone. The stellar EUV radiation drives atmospheric heating, while the FUV (in particular, Lyα) and NUV radiation fields regulate the atmospheric chemist…
The X-Ray Eclipse Geometry of the Super-soft X-Ray Source CAL 87
Lopes de Oliveira, R.; Ribeiro, T.; Borges, B. W.
We explore XMM-Newton observations of the eclipsing super-soft X-ray source CAL 87 in order to map the accretion structures of the system. Indirect imaging techniques were applied in X-ray light curves to provide eclipse maps. The surface brightness distribution exhibits an extended and symmetric emission, and a feature is revealed from the hardes…
Comparison of Galaxy Clusters Selected by Weak-lensing, Optical Spectroscopy, and X-Rays in the Deep Lens Survey F2 Field
Jones, Christine; Geller, Margaret J.; Kurtz, Michael J. +6 more
We compare galaxy clusters selected in Chandra and XMM-Newton X-ray observations of the 4 deg2 Deep Lens Survey (DLS) F2 field to the cluster samples previously selected in the same field from a sensitive weak-lensing shear map derived from the DLS and from a detailed galaxy redshift survey—the Smithsonian Hectospec Lensing Survey (SHEL…
A new HCN maser in IRAS 15082-4808
Zijlstra, A. A.; Fuller, G. A.; Smith, C. L.
We have identified a new vibrational HCN maser at 89.087 GHz in the asymptotic giant branch (AGB) star IRAS 15082-4808, a maser which is thought to trace the innermost region of an AGB envelope. The observations of this maser at three epochs are presented: two positive detections and one null detection. The line profile has varied between the posi…
The void in the Sculptor group spiral galaxy NGC 247
Wagner-Kaiser, R.; Sarajedini, A.; De Maio, T. +1 more
The dwarf galaxy NGC 247, located in the Sculptor Filament, displays an apparent void on the north side of its spiral disc. The existence of the void in the disc of this dwarf galaxy has been known for some time, but the exact nature and cause of this strange feature has remained unclear. We investigate the properties of the void in the disc of NG…
Composite inflation confronts BICEP2 and PLANCK
Channuie, Phongpichit; Karwan, Khamphee
We examine observational constraints on single-field inflation in which the inflaton is a composite field stemming from a four-dimensional strongly interacting field theory. We confront the predictions with the Planck and very recent BICEP2 data. In the large non-minimal coupling regions, we discover for the minimal composite inflationary model th…
The Gas-rich Circumbinary Disk of HR 4049. I. A Detailed Study of the Mid-infrared Spectrum
Cami, J.; Malek, S. E.
We present a detailed analysis of the mid-infrared spectrum of the peculiar evolved object HR 4049. The full Spitzer-IRS high-resolution spectrum shows a wealth of emission with prominent features from CO2 and H2O and possible contributions from HCN and OH. We model the molecular emission and find that it originates from a ma…
Symbiotic stars in X-rays. II. Faint sources detected with XMM-Newton and Chandra
Nuñez, N. E.; Mukai, K.; Luna, G. J. M. +1 more
We report the detection from four symbiotic stars that were not known to be X-ray sources. These four object show a β-type X-ray spectrum, that is, their spectra can be modeled with an absorbed optically thin thermal emission with temperatures of a few million degrees. Photometric series obtained with the Optical Monitor on board XMM-Newton from V…