Search Publications
Silicates in Hale-Bopp: hints from laboratory studies
Brucato, J. R.; Mennella, V.; Colangeli, L. +2 more
The recent passage of the Hale-Bopp (C/1995 O1) comet has provided the first opportunity to analyse the infrared spectral properties of a bright comet both from the ground and by the ISO space observatory. Previous works have already been dedicated to study the potential candidates to reproduce the cometary feature at 10 µm observed for diff…
VLT and HST observations of a candidate high redshift elliptical galaxy in the Hubble Deep Field South
Dickinson, M.; Treu, T.; Rosati, P. +9 more
The combined use of the ESO Very Large Telescope (VLT) UT1 Science Verification (SV) images and of the Hubble Space Telescope (HST) Hubble Deep Field South observations allows us to strengthen the identification as a candidate elliptical galaxy of the Extremely Red Object HDFS 223251-603910 previously identified by us on the basis of NICMOS and Ce…
PKS 1004+13: A High-Inclination, Highly Absorbed Radio-loud QSO--the First Radio-loud Broad Absorption Line QSO at Low Redshift?
Brandt, W. N.; Laor, A.; Wills, Beverley J.
The existence of broad absorption line (BAL) outflows in only radio-quiet QSOs was thought to be an important clue to mass ejection and the radio-loud-radio-quiet dichotomy. Recently, a few radio-loud BAL QSOs have been discovered at high redshift. We present evidence that PKS 1004+13 is a radio-loud BAL QSO. It would be the first known at low red…
Explosive events in the solar atmosphere
Doyle, J. G.; Erdélyi, R.; Sarro, L. M. +1 more
Two examples of explosive events observed with SUMER in transition region spectral lines are reported here; one detected in C iv 1548 Angstroms, in a region within the northern polar coronal hole, and the other in O vi 1032 Angstroms, in an active region. The event measured in C iv lasted ~ 3 min and extended approximately a region of 8 arc sec al…
The Optical Gravitational Lensing Experiment. UBVI Photometry of Stars in Baade's Window
Udalski, A.; Wozniak, P.; Kubiak, M. +5 more
We present UBVI photometry for 8530 stars in Baade's Window obtained during the OGLE-II microlensing survey. Among these are over one thousand red clump giants. 1391 of them have photometry with errors smaller than 0.04, 0.06, 0.12, and 0.20 mag in the I, V, B, and U-band, respectively. We constructed a map of interstellar reddening. The corrected…
An HST surface photometric study of ultraluminous infrared galaxies
Mao, S.; Wu, H.; Zheng, Z. +3 more
We study the surface photometry for 13 single-nucleus ultraluminous IRAS galaxies (ULIRGs), selected from a parent sample of 58 galaxies obtained in a Hubble Space Telescope I-band snapshot survey. These galaxies can be classified into two classes using a quantitative chi (2) criterion based on whether their surface brightness profiles are well fi…
Precise Interplanetary Network Localization of a New Soft Gamma Repeater, SGR 1627-41
Cline, T.; Hurley, K.; Kouveliotou, C. +5 more
We present Ulysses, Konus-Wind, and BATSE observations of bursts from a new soft gamma repeater that was active in 1998 June and July. Triangulation of the bursts results in a ~1.8d by 16" error box whose area is ~7.6 arcmin2 and which contains the Galactic supernova remnant G337.0-0.1. This error box intersects the position of a BeppoS…
Hubble Space Telescope spectroscopy of hot helium-rich white dwarfs: metal abundances along the cooling sequence
Dreizler, S.
Metal abundances are the indicators of the chemical evolution in white dwarfs, which is dominated by the element separation due to the strong gravitational field. A reliable analysis and interpretation requires high resolution and high signal-to-noise UV spectroscopy. For hot helium rich DO white dwarfs this is currently only feasible with the Hub…
The Three-dimensional Coronal Magnetic Field during Whole Sun Month
Thompson, B. J.; Hoeksema, J. T.; Lazarus, A. J. +11 more
Combining models and observations, we study the three-dimensional coronal magnetic field during a period of extensive coordinated solar observations and analysis known as the Whole Sun Month (WSM) campaign (1996 August 10-September 8). The two main goals of the WSM campaign are addressed in this paper, namely, (1) to use the field configuration to…
Multiwavelength Study of the Starburst Galaxy NGC 7714. I. Ultraviolet-Optical Spectroscopy
Leitherer, Claus; Pasquali, Anna; González Delgado, Rosa M. +2 more
We have studied the physical conditions in the central 300 pc of the prototypical starburst galaxy NGC 7714. Our analysis is based on ultraviolet spectroscopy with the HST/GHRS and ground-based optical observations, and it also covers X-ray and radio data taken from the literature. The data are interpreted using evolutionary models optimized for y…