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Phase Differences and Gains between Intensity and Velocity in Low-Degree Acoustic Modes Measured by SOHO
Jiménez, Antonio; Severino, Giuseppe; Roca Cortés, Teodoro +1 more
Helioseismic instruments aboard SOHO are making possible a more accurate way of investigating the internal structure of the Sun. Making use of the different techniques and characteristics of these instruments, it is possible to measure solar oscillations as variations of the photospheric velocity (GOLF, MDI) or as irradiance and radiance fluctuati…
Interpreting the Solar Limb Shape Distortions
Armstrong, James; Kuhn, J. R.
Accurate measurements of the solar oblateness have recently been obtained from the SOHO/MDI satellite experiment. The new data are sufficiently accurate to measure nonnegligible multipole shape terms of higher order than the oblateness. Here we extend earlier solar limb shape calculations and compare the new data with the helioseismic evidence for…
Detection of H2 Pure Rotational Line Emission from the GG Tauri Binary System
van Dishoeck, Ewine F.; Blake, Geoffrey A.; Hogerheijde, Michiel R. +2 more
We present the first detection of the low-lying pure rotational emission lines of H2 from circumstellar disks around T Tauri stars, using the Short Wavelength Spectrometer on the Infrared Space Observatory. These lines provide a direct measure of the total amount of warm molecular gas in disks. The J=2-->0 S(0) line at 28.218 µ…
Goddard High-Resolution Spectrograph Observations of the B III Resonance Doublet in Early B Stars: Abundances and Isotope Ratios
Wahlgren, Glenn M.; Proffitt, Charles R.; Jönsson, Per +2 more
Boron abundances and isotope ratios in two early B stars have been measured by using the Hubble Space Telescope's Goddard High-Resolution Spectrograph (GHRS) in order to observe the B III resonance doublet near 2066 Å. We also report new experimental and theoretical results for the wavelengths, isotope shift, and hyperfine structure of these boron…
Stellar Masses, Kinematics, and White Dwarf Composition for Three Close DA+DME Binaries
Vennes, Stéphane; Thorstensen, John R.; Polomski, Elisha F.
We determine the mass functions and mass ratios for three close white dwarf plus red dwarf binaries (EUVE J0720-317, 1016-053, and 2013+400). Hubble Space Telescope Goddard High-Resolution Spectrograph spectra of the He II λ1640 and C IV λ1550 spectral lines trace the white dwarf orbital motion, and Hamilton Spectrograph echelle spectra (Lick Obse…
The Starburst-Active Galactic Nucleus Connection in Active Galaxies: The MassiveNuclear Star-Forming Disk in NGC 4303
Colina, L.; Arribas, S.
Two-dimensional spectroscopy of the low-redshift active galaxy NGC 4303 obtained with the Two-Dimensional Fiber ISIS System is presented. The ionization structure and velocity field of the nuclear region of this galaxy, where a compact UV-bright spiral structure connected with the UV-bright core has been detected with the Hubble Space Telescope (H…
A NICMOS Search for High-Redshift Elliptical Galaxy Candidates
Stiavelli, Massimo; Treu, Tommaso
We have collected optical follow-up observations from the ground and the Hubble Space Telescope (HST) for 13.74 arcmin2 of archival images taken with the HST Near-Infrared Camera and Multiobject Spectrograph (NICMOS). We use two criteria to select E/S0 galaxy candidates at z>~1 and z>~1.5 (high-redshift elliptical candidates [HizE…
Hubble Space Telescope Faint Object Spectrograph Optical and Ultraviolet Spectroscopy of the Bow Shock HH 47A
Hartigan, Patrick; Raymond, John; Tumlinson, Jason +2 more
We present new spectra obtained with the Faint Object Spectrograph aboard the Hubble Space Telescope of the HH 47A bow shock and Mach disk that cover the entire spectral range between λλ2220 and 6810. In addition to emission lines seen previously from HH objects, we uncover over a dozen weak Fe IItransitions in the ultraviolet. The flux ratios bet…
Wide-Field CCD Photometry of the Globular Cluster M30
Bolte, Michael; Hesser, James E.; Sandquist, Eric L. +2 more
We present new VI photometry for the halo globular cluster M30 (NGC 7099=C2137-174) and compute luminosity functions (LFs) in both bands for samples of about 15,000 hydrogen-burning stars from near the tip of the red giant branch (RGB) to over 4 mag below the main-sequence (MS) turnoff (TO). We confirm previously observed features of the LF that a…
Dust Formation in the Hot Massive Binary HD 192641 = WR 137 (WC7 + OB)
Moffat, Anthony F. J.; Marchenko, Sergey V.; Grosdidier, Yves
Medium band (H' and K') images of the episodic dust-forming, long-period (~13 yr) WC7 + OB binary WR 137 were obtained with the Near-Infrared Camera and Multiobject Spectrometer 2 camera of the Hubble Space Telescope during periastron passage in 1997-1998. We have resolved IR-emitting dust in the close environment of this system. The dust emission…