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Low-Redshift Damped Lyα Galaxies toward the Quasars B2 0827+243, PKS 0952+179, PKS 1127-145, and PKS 1629+120
Turnshek, David A.; Rao, Sandhya M.; Bergeron, Jacqueline +3 more
We present optical and near-infrared ground-based imaging results on four low-redshift damped Lyα (DLA) galaxies. The corresponding DLA systems were discovered in our Hubble Space Telescope spectroscopic surveys for DLA lines in known strong Mg II absorption-line systems toward the quasars B2 0827+243 (zDLA=0.525), PKS 0952+179 (zD…
The remarkable rapid X-ray, ultraviolet, optical and infrared variability in the black hole XTE J1118+480
Chaty, S.; Cui, W.; Horne, Keith +6 more
The transient black-hole binary XTE J1118+480 exhibited dramatic rapid variability at all wavelengths which were suitably observed during its 2000 April-July outburst. We examine time-resolved X-ray, ultraviolet, optical and infrared data spanning the plateau phase of the outburst. We find that both X-ray and infrared bands show large amplitude va…
Weak-Field Magnetogram Calibration using Advanced Stokes Polarimeter Flux Density Maps - II. SOHO/MDI Full-Disk Mode Calibration
Lites, B. W.; Berger, T. E.
Cotemporal Ni i 676.8 nm full-disk magnetograms from the Michelson Doppler Interferometer (MDI) instrument on SOHO and the Advanced Stokes Polarimeter (ASP) are quantitatively compared using observations of active region AR 8218, a large negative polarity sunspot group observed at S20 W22 on 13 May 1998. MDI produces flux density estimates based o…
The Rotation of the Deep Solar Layers
Henney, C. J.; García, R. A.; Corbard, T. +3 more
From the analysis of low-order GOLF+MDI sectoral modes (l<=3, 6<=n<=15, |m|=l) and LOWL data (l>3), we derive the radial rotation profile by assuming no latitudinal dependence in the solar core. These low-order acoustic modes contain the most statistically significant information about the rotation of the deepest solar layers and shoul…
The Assembly of Massive Galaxies from Near-Infrared Observations of the Hubble Deep Field-South
Fontana, A.; Vanzella, E.; Cristiani, S. +7 more
We use a deep KAB<=25 galaxy sample in the Hubble Deep Field-South to trace the evolution of the cosmological stellar mass density from z~=0.5 to z~=3. We find clear evidence for a decrease of the average stellar mass density at high redshift, 2<=z<=3.5, that is 15+25-5% of the local value, 2 times higher …
Parent Stars of Extrasolar Planets. VII. New Abundance Analyses of 30 Systems
Suntzeff, Nicholas B.; Gonzalez, Guillermo; Laws, Chris +4 more
The results of new spectroscopic analyses of 30 stars with giant planet and/or brown dwarf companions are presented. Values for Teff and [Fe/H] are used in conjunction with Hipparcos data and Padua isochrones to derive masses, ages, and theoretical surface gravities. These new data are combined with spectroscopic and photometric metalli…
A deep survey of heavy element lines in planetary nebulae - I. Observations and forbidden-line densities, temperatures and abundances
Tsamis, Y. G.; Barlow, M. J.; Liu, X. -W. +2 more
We present deep optical spectrophotometry of 12 Galactic planetary nebulae (PNe) and three Magellanic Cloud PNe. Nine of the Galactic PNe were observed by scanning the slit of the spectrograph across the nebula, yielding relative line intensities for the entire nebula that are suitable for comparison with integrated nebular fluxes measured in othe…
Hubble Space Telescope Images of Submillimeter Sources: Large Irregular Galaxies at High Redshift
Chapman, S. C.; Conselice, C.; Yan, H. +2 more
We present new Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) high-resolution optical imaging of a sample of 13 submillimeter luminous galaxies for which the optical emission has been pinpointed either through radio 1.4 GHz or millimeter interferometry. We find a predominance of irregular and complex morphologies in the sample,…
A Search for CMEs Associated with Big Flares
Andrews, M. D.
The relationship between flares and coronal mass ejections (CMEs) remains a topic of active research. This paper considers a complete set of 311 M- and X-class GOES soft X-ray flares observed during the years 1996-1999. The durations of these flares have been determined as part of this study. Possible CME candidates for the 229 flares with good LA…
A New Method for Estimating Widths, Velocities, and Source Location of Halo Coronal Mass Ejections
Gopalswamy, N.; Yashiro, S.; Michałek, G.
It is well known that coronagraphic observations of halo coronal mass ejections (CMEs) are subject to projection effects. Viewing in the plane of the sky does not allow us to determine the crucial parameters that define the geoeffectiveness of CMEs, such as the space speed, width, or source location. Assuming that halo CMEs have constant velocitie…