Search Publications
Detection of warm SO_2 gas in oxygen-rich AGB stars
Waters, L. B. F. M.; Onaka, T.; Yamamura, I. +2 more
We report the discovery of the nu_3 band of SO_2 at 7.3 mu m in the ISO/SWS spectra of oxygen-rich AGB stars. The band is clearly detected in three stars, UX Cyg, o Cet and T Cep, and marginally detected in at least four other stars. The band is seen in absorption in UX Cyg, while it is in emission in o Cet. Seven spectra of T Cep taken at differe…
Zeroing the Stellar Isochrone Scale: The Red Giant Clump Luminosity at Intermediate Metallicity
Twarog, Bruce A.; Anthony-Twarog, Barbara J.; Bricker, Andrew R.
The color-magnitude diagrams of the open clusters NGC 2420 and NGC 2506 have been investigated as intermediate links between the solar neighborhood and the Magellanic Clouds. Two sets of theoretical isochrones that include convective overshoot are zeroed to the Sun at solar abundance and to the unevolved main-sequence dwarfs of the Hipparcos Catal…
Parsec-Scale Radio Structures in the Nuclei of Four Seyfert Galaxies
Kukula, Marek J.; Ghosh, Tapasi; Pedlar, Alan +1 more
We present 18 cm radio maps of four Seyfert nuclei, Mrk 1, Mrk 3, Mrk 231, and Mrk 463E, made with the European VLBI Network (EVN). Linear radio structures are present in three out of four sources on scales of ~100 pc to ~1 kpc, and the 20 mas beam of the EVN enables us to resolve details within the radio structures on scales of less than 10 pc. M…
The zabs ~ zem absorption line systems toward QSO J 2233-606 in the Hubble Deep Field South: NE viii lambda lambda 770,780 absorption and partial coverage absorption line systems toward QSO J 2233-606
Petitjean, Patrick; Srianand, R.
Results of a careful analysis of the highly ionized absorption systems, observed over the redshift range 2.198-2.2215 in the zem = 2.24 HDFS-QSO J 2233-606, are presented. The strength and covering factor of the O VI and Ne VIII absorption lines suggest that the gas is closely associated with the AGN. In addition, most of the lines show…
Transition-Region Network Boundaries in the Quiet Sun: Width Variation with Temperature as Observed with CDS on SOHO
Vial, J. -C.; Patsourakos, S.; Gabriel, A. H. +1 more
We report here the results of a study of the temperature variation of the network boundary thicknesses in the quiet-Sun transition region. A Fourier-based two-dimensional autocorrelation method has been applied to 240''×240'' rasters obtained in several transition-region lines by the CDS spectrometer on SOHO. The quantitative…
Speckle Observations of Binary Stars with the WIYN Telescope. I. Measures During 1997
Girard, Terrence M.; van Altena, William F.; Horch, Elliott +3 more
Two hundred seventy-seven position angle and separation measures of 154 double stars are presented. Three of the systems were previously unknown to be double, and 16 other systems were discovered earlier this decade by the Hipparcos satellite. Measures are derived from speckle observations taken with the Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5 m te…
Large-Scale Flows in the Solar Interior: Effect of Asymmetry in Peak Profiles
Basu, Sarbani; Antia, H. M.
Ring diagram analysis can be used to study large-scale velocity fields in the outer part of the solar convection zone. All previous works assume that the peak profiles in the solar oscillation power spectrum are symmetrical. However, it has now been demonstrated that the peaks are not symmetrical. In this work we study how the explicit use of asym…
The Multiple Phases of Interstellar and Halo Gas in a Possible Group of Galaxies at Z~1
Charlton, Jane C.; Churchill, Christopher W.
We used HIRES/Keck profiles (R~6 km s^-1) of Mg II and Fe II in combination with Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) spectra (R~230 km s^-1) to place constraints on the physical conditions (metallicities, ionization conditions, and multiphase distribution) of absorbing gas in three galaxies at z=0.9254, 0.9276, and 0.9343 …
ISO-LWS observations of Herbig Ae/Be stars. II. Molecular lines
Liseau, R.; White, G. J.; Palla, F. +15 more
We present the first ISO-LWS observations of the molecular FIR lines in 3 out of a sample of 11 Herbig Ae/Be stars (HAEBE), namely IRAS12496-7650, RCrA and LkHα 234. High-J rotational CO lines (from Jup = 14 to Jup = 19) have been observed in all the spectra, while two (at 79 mu m and 84 mu m) and three OH lines (at 71 mu m, …
Comment on ``Indication, from Pioneer 10/11, Galileo, and Ulysses Data, of an Apparent Anomalous, Weak, Long-Range Acceleration''
Katz, J. I.
A Comment on the Letter by John D. Anderson et al., Phys. Rev. Lett. 81, 2858 (1998). The authors of the Letter offer a Reply.