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The Angular Diameter and Fundamental Parameters of Sirius A
Tuthill, P. G.; Davis, J.; Ireland, M. J. +3 more
The Sydney University Stellar Interferometer (SUSI) has been used to make a new determination of the angular diameter of Sirius A. The observations were made at an effective wavelength of 694.1nm and the new value for the limb-darkened angular diameter is 6.048+/-0.040mas (+/-0.66%). This new result is compared with previous measurements and is fo…
High-resolution Spectroscopy and Spectropolarimetry of Some Late F- / Early G-type Sun-like Stars as Targets for Zeeman Doppler Imaging
Hart, R.; Burton, D.; Marsden, S. C. +4 more
High-resolution spectroscopy and spectropolarimetry have been undertaken at the Anglo-Australian Telescope in order to identify suitable targets for magnetic studies of young Sun-like stars, for the proxy study of early solar evolution. This study involved the investigation of some variable late F- / early G-type Sun-like stars originally identifi…
An All-Sky Atlas of Radio/X-ray Associations
Flesch, E.
An all-sky comprehensive catalogue of calculated radio and X-ray associations to optical objects is presented. Included are X-ray sources from XMM-Newton, Chandra and ROSAT catalogues, radio sources from NVSS, FIRST and SUMSS catalogues, and optical data, identifications and redshifts from the APM, USNO-A, SDSS-DR7 and the extant literature. This …
A Direct Detection of Gas Accretion: The Lyman Limit System in 3C 232
Danforth, Charles W.; Stocke, John T.; Keeney, Brian A.
The gas added to and removed from galaxies over cosmic time greatly affects their stellar populations and star formation rates. QSO absorption line studies in close QSO/galaxy pairs create a unique opportunity to study the physical conditions and kinematics of this gas. Here we present new Hubble Space Telescope (HST) images of the QSO/galaxy pair…
A FUSE View of Winds from the Central Stars of Planetary Nebulae
Guerrero, Martín A.; Ramos-Larios, Gerardo; Massa, Derck
Since the IUE satellite produced a vast collection of high-resolution UV spectra of the central stars of planetary nebulae (CSPNe), there has not been any further systematic study of the stellar winds of these stars. The high spectral resolution, sensitivity and large number of archival observations in the FUSE archive allow the study of the stell…
Spatially Resolved Spectroscopy of Starburst and Post-Starburst Galaxies in the Rich z~0.55 Cluster CL 0016+16 1
Kuntschner, Harald; Couch, Warrick J.; Pracy, Michael B.
We have used the Low Resolution Imaging Spectrograph on the W. M. Keck I telescope to obtain spatially resolved spectroscopy of a small sample of six `post-starburst' and three `dusty-starburst' galaxies in the rich cluster CL 0016+16 at z=0.55. We use this to measure radial profiles of the Hδ and [OII]λ3727 lines which are diagnostic probes of th…
A Survey of IUE Spectra of the Active Binary System UX Arietis
Ekmekçi, Fehmi
To investigate the ultraviolet (UV) activity of the bright, non-eclipsing, double-lined spectroscopic binary system UX Ari, IUE spectra (194 images) were taken from the IUE archive. The spectra, obtained during the period 1978-1996, show emission lines originating in the chromosphere and transition region. The long-wavelength low dispersion spectr…
Measuring Cosmic Elements with Gamma-Ray Telescopes
Diehl, Roland
Gamma-ray telescopes are capable of measuring radioactive trace isotopes from cosmic nucleosynthesis events. Such measurements address new isotope production rather directly for a few key isotopes such as 44Ti, 26Al, 60Fe, and 56Ni, as well as positrons from the β+-decay variety. Experiments o…
Kinematics of M-Type Giant Semi-Regular Variables from the Hipparcos Catalogue
Yeşilyaprak, C.; Aslan, Z.
The kinematics of M-type (O-rich) giant semi-regular (SR) variable stars were examined. They were grouped with respect to their relative parallax errors (ɛπ/π) in order to study the stars having relatively better parallax, and with the period limit (70 d). The spatial and velocity distributions were examined and the results were compare…
Mathematical Morphology: Star/Galaxy Differentiation & Galaxy Morphology Classification
Moore, Jason A.; Pimbblet, Kevin A.; Drinkwater, Michael J.
We present an application of Mathematical Morphology (MM) for the classification of astronomical objects, both for star/galaxy differentiation and galaxy morphology classification. We demonstrate that, for CCD images, 99.3+/-3.8% of galaxies can be separated from stars using MM, with 19.4+/-7.9% of the stars being misclassified. We demonstrate tha…