Search Publications
Abundance Anomalies in CP Crucis (Nova Crux 1996)
Lumsden, S. L.; Krautter, Joachim; Gehrz, R. D. +15 more
We present spectroscopic observations of the classical nova CP Crucis (Nova Crux 1996) obtained with the Infrared Space Observatory Short Wavelength Spectrometer (ISO SWS) and the Anglo-Australian Telescope using both the Infrared Imaging Spectrograph and the Royal Greenwich Observatory Spectrograph. From the expansion parallax, we find that CP Cr…
The Dusty Environment of Quasars: Far-Infrared Properties of Optical Quasars
Grazian, Andrea; La Franca, Fabio; Cristiani, Stefano +2 more
We present Infrared Space Observatory (ISO) far-IR photometry of a complete subsample of optically selected bright quasars belonging to two complete surveys selected through multicolor (U, B, V, R, I) techniques. The ISOPHOT camera on board the ISO satellite was used to target these quasars at wavelengths of 7.3, 11.5, 60, 100, and 160 µm. A…
Positions of Uranus and Its Main Satellites
Veiga, Carlos H.; Vieira Martins, Roberto; Andrei, Alexandre H.
We present astrometric positions of Uranus and its satellites Miranda, Ariel, Umbriel, Titania, and Oberon, determined in the International Celestial Reference System, from 1758 frames observed over 105 nights between 1982 and 1998. All the positions of the satellites were reduced using secondary frames referred to the Tycho-2 Catalogue from photo…
Optical Positions of ICRF Sources Using UCAC Reference Stars
Zacharias, N.; Assafin, M.; Zacharias, M. I. +4 more
New optical positions on the 30 mas precision level have been obtained for 172 extragalactic International Celestial Reference Frame (ICRF) sources mainly in the range -30°<=δ<=+25°. Results are presented from a pilot investigation including four Cerro Tololo (CTIO) 0.9 m runs (1999-2001). Reference stars in the R~10-16.5 mag range from a pr…
Radio-selected Galaxies in Very Rich Clusters at z<=0.25. II. Radio Properties and Analysis
Owen, Frazer N.; Morrison, Glenn E.
We report on the properties of radio-selected galaxies within 30 very rich Abell clusters with z<~0.25. The radio, optical, and X-ray data for these clusters were presented in Paper I. These radio data sample the ultrafaint (L1.4>=2×1022 W Hz-1) radio galaxy population with MR<=-21 using the wel…
Is B1422+231 a ``Golden Lens''?
Raychaudhury, Somak; Saha, Prasenjit; Williams, Liliya L. R.
The object B1422+231 is a quadruply imaged QSO with an exceptionally large lensing contribution from group galaxies other than main lensing galaxy. We have detected diffuse X-rays from the galaxy group in archival Chandra observations; the inferred temperature is consistent with the published velocity dispersion. We explore the range of possible m…
Iterative Techniques for the Decomposition of Long-Slit Spectra
Walsh, J. R.; Lucy, L. B.
Two iterative techniques are described for decomposing a long-slit spectrum into the individual spectra of the point sources along the slit and the spectrum of the underlying background. One technique imposes the strong constraint that the spectrum of the background be spatially invariant; the other relaxes this constraint. Both techniques are app…
High Spectral Resolution H2 Measurements of Herbig-Haro Objects 38, 46/47, and 120
Schwartz, Richard D.; Greene, Thomas P.
We report high spectral resolution (R~=20,000) measurements of the H2 1-0S(1) line in Herbig-Haro objects 38, 46/47, and 120. The long-slit spectra reveal complex velocity structure with evidence for bow-shock structures, as well as prompt entrainment and shock heating of ambient molecular gas. Individual knots within HH 38 show distinc…
The Opacity of Nearby Galaxies from Counts of Background Galaxies. II. Limits of the Synthetic Field Method
Loinard, Laurent; Allen, Ronald J.; Muller, Sébastien +1 more
Recently, we have developed and calibrated the Synthetic Field Method to derive the total extinction through disk galaxies. The method is based on the number counts and colors of distant background field galaxies that can be seen through the foreground object; it is the only method capable of determining extinction without a priori assumptions abo…
Hubble Space Telescope NICMOS Observations of the Embedded Cluster in NGC 2024: Constraints on the Initial Mass Function and Binary Fraction
Young, Erick T.; Meyer, Michael R.; Cotera, Angela S. +1 more
We present an analysis of NICMOS observations of the embedded cluster associated with NGC 2024. An analysis of the cluster color-magnitude diagram (CMD) using the models of D'Antona & Mazzitelli and Baraffe et al. (published in 1997 and 1998, respectively) indicates that the ratio of intermediate-mass (1.0-10.0 Msolar) to low-mass (…