Search Publications
The ISO/SWS Spectrum of IRC +10216: The Vibrational Bands of C2H2 and HCN
Cernicharo, José; Yamamura, Issei; González-Alfonso, Eduardo +4 more
We present the Infrared Space Observatory/Short-Wavelength Spectrometer full grating resolution spectrum of IRC +10216, which is dominated by strong absorption/emission bands of C2H2 and HCN. All C2H2 bands and the strong near-infrared stretching bands of HCN are observed in absorption, whereas the funda…
Abundances and Physical Conditions in the Warm Neutral Medium toward µ Columbae
Savage, Blair D.; Howk, J. Christopher; Fabian, Dirk
We present ultraviolet interstellar absorption-line measurements for the sightline toward the O9.5 V star µ Columbae (l=237.3d, b=-27.1d d~400 pc, z~180 pc; <nHI>~0.06 cm-3) obtained with the Goddard High Resolution Spectrograph (GHRS) on board the Hubble Space Telescope. These archival data represent the most com…
Triple Bars and Complex Central Structures in Disk Galaxies
Erwin, Peter; Sparke, Linda S.
We present an analysis of ground-based and Hubble Space Telescope images of three early-type barred galaxies. The first, NGC 2681, may be the clearest example yet of a galaxy with three concentric bars. The two other galaxies were previously suggested to be triple barred. Our analysis shows that while NGC 3945 is probably double barred, NGC 4371 h…
Molecular Gas in 3C 293: The First Detection of CO Emission and Absorption in a Fanaroff-Riley Type II Radio Galaxy
Sanders, D. B.; Surace, J. A.; Evans, A. S. +1 more
The first detection of CO emission in a Fanaroff and Riley type II (i.e., edge-brightened radio lobe morphology) radio galaxy is presented. Multiwavelength (0.36-2.17 µm) imaging of 3C 293 shows it to be a disk galaxy with an optical jet or tidal tail extending toward what appears to be a companion galaxy 28 kpc away via a low surface bright…
Multiplicity of the HH 111 jet source: it Hubble Space Telescope NICMOS images and VLA maps
Bally, John; Rodríguez, Luis F.; Reipurth, Bo +2 more
We have observed the region around the HH 111 jet source with NICMOS onboard the Hubble Space Telescope, using two filters, F160W and F205W, which besides stellar continuum transmit the [FeII] 1.64 mu m and H_2 2.12 mu m emission lines, respectively. The jet can now be traced to within 2\farcs4 of the VLA source. In the F205W filter we detect for …
AGNs with composite spectra. II. Additional data
Véron-Cetty, M. -P.; Véron, P.; Gonçalves, A. C.
In a previous paper \cite[(Véron et al. 1997)]{ver97} we presented medium resolution (3.4 Angstroms FWHM) spectroscopic observations of 15 ``transition objects'', selected for having an ambiguous location in the \cite[Veilleux & Osterbrock (1987)]{vei87} diagnostic diagrams, and showed that most of them were in fact ``composite'', this being d…
TT Arietis: the low state revisited
Gänsicke, B. T.; Beuermann, K.; Sion, E. M. +3 more
We present optical and ultraviolet spectroscopy of TT Ari obtained during the 1982-85 low state. In November/December 1983, accretion had almost completely ceased, unveiling both the white dwarf and the secondary star. The IUE spectrum obtained during that occasion contains absorption lines of Lyalpha , \Si IV, \C IV, and \He II. We derive a photo…
What heats the bright H II regions in I ZW 18?
Schaerer, D.; Stasińska, G.
We have used the radiation field from a starburst population synthesis model appropriate for the brightest H ii region of I Zw 18 to perform a photoionization model analysis of this object. We have investigated whether, with the observed nebular density distribution as revealed by the HST images and a total stellar radiation compatible with the ob…
The Deuterium Abundance at z=0.701Z = 0.701 toward QSO 1718+4807
Savage, Blair D.; Lu, Limin; Burles, Scott +3 more
We present constraints on the deuterium-to-hydrogen ratio (D/H) in the metal-poor gas cloud at redshift z=0.701 toward QSO 1718+4807. We use new Keck spectra in addition to Hubble Space Telescope (HST) and International Ultraviolet Explorer spectra. We use an improved redshift and a lower H I column density to model the absorption. The HST spectru…
The IUE INES System: Improved data extraction procedures for IUE
Schartel, N.; Rodríguez-Pascual, P. M.; Wamsteker, W. +1 more
We present the extraction and processing of the IUE Low Dispersion spectra within the framework of the ESA ``IUE Newly Extracted Spectra'' (INES) System. Weak points of SWET, the optimal extraction implementation to produce the NEWSIPS output products (extracted spectra) are discussed, and the procedures implemented in INES to solve these problems…