Search Publications
A Hubble Space Telescope Snapshot Survey of Dynamically Close Galaxy Pairs in the CNOC2 Redshift Survey
Simard, L.; Carlberg, R. G.; Pritchet, C. J. +3 more
We compare the structural properties of two classes of galaxies at intermediate redshift: those in dynamically close galaxy pairs, and those that are isolated. Both samples are selected from the Canadian Network for Observational Cosmology field galaxy redshift survey (CNOC2) and have redshifts in the range 0.1<z<0.6. Hubble Space Telescope …
Discovery and monitoring of the likely IR counterpart of SGR 1806-20 during the 2004 γ-ray burst-active state
Covino, S.; Campana, S.; Götz, D. +9 more
The sky region including the Chandra position of SGR 1806-20 was monitored in the IR band during 2004, following its increased high energy bursting activity. Observations were performed using NAOS-CONICA, the adaptive optics IR camera mounted on Yepun VLT, which provided images of unprecedented quality (FWHM better than 0.1 arcsec). After the 2004…
Self-Consistent Dynamic Models of Steady Ionization Fronts. I. Weak-D and Weak-R Fronts
Henney, W. J.; Ferland, G. J.; Williams, R. J. R. +1 more
We present a method for including steady state gas flows in the plasma physics code Cloudy, which was previously restricted to modeling static configurations. The numerical algorithms are described in detail, together with an example application to plane-parallel ionization-bounded H II regions. As well as providing the foundation for future appli…
A Candidate Neutron Star Associated with Galactic Center Supernova Remnant Sagittarius A East
Maeda, Yoshitomo; Garmire, Gordon P.; Baganoff, Frederick K. +6 more
We present imaging and spectral studies of the supernova remnant (SNR) Sagittarius (Sgr) A East from deep observations with Chandra. The spatially resolved spectral analysis of Sgr A East reveals the presence of a two-temperature thermal plasma (kT~1 and 5 keV) near the center of the SNR. The central region is dominated by emission from highly ion…
Hubble Space Telescope Observations of Nine High-Redshift ESSENCE Supernovae1,
Filippenko, Alexei V.; Wood-Vasey, W. Michael; Foley, Ryan J. +29 more
We present broadband light curves of nine supernovae ranging in redshift from 0.5 to 0.8. The supernovae were discovered as part of the ESSENCE project, and the light curves are a combination of Cerro Tololo 4 m and Hubble Space Telescope (HST) photometry. On the basis of spectra and/or light-curve fitting, eight of these objects are definitely Ty…
Deep Impact: Working Properties for the Target Nucleus Comet 9P/Tempel 1
Fernández, Yanga R.; A'Hearn, Michael F.; Pittichová, Jana +13 more
In 1998, Comet 9P/Tempel 1 was chosen as the target of the Deep Impact mission (A’Hearn, M. F., Belton, M. J. S., and Delamere, A., Space Sci. Rev., 2005) even though very little was known about its physical properties. Efforts were immediately begun to improve this situation by the Deep Impact Science Team leading to the founding of a worldwide o…
Absolute Proper Motion of the Sagittarius Dwarf Galaxy and of the Outer Regions of the Milky Way Bulge
Girard, Terrence M.; van Altena, William F.; López, Carlos E. +1 more
We have determined the absolute proper motion of the Sagittarius dwarf spheroidal galaxy (Sgr) from the Southern Proper Motion Catalog 3, by selecting red giant candidates from the Two Micron All Sky Survey. We obtain µlcosb=-2.35+/-0.20 and µb=2.07+/-0.20 mas yr-1. Using the same procedure, we also det…
An optical time delay for the double gravitational lens system FBQ 0951+2635
Lidman, C.; Hjorth, J.; Jakobsson, P. +3 more
We present optical R-band light curves of the double gravitationally lensed quasar FBQ 0951+2635 from observations obtained at the Nordic Optical Telescope between March 1999 and June 2001. A time delay of Δ τ = 16 ± 2 days (1σ) is determined from the light curves. New constraints on the lensing geometry are provided by the position and ellipticit…
Highly Ionized Gas in the Galactic Halo and the High-Velocity Clouds toward PG 1116+215
Tripp, Todd M.; Sembach, Kenneth R.; Savage, Blair D. +1 more
We have obtained high-resolution Far Ultraviolet Spectroscopic Explorer (FUSE) and Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) echelle observations of the quasar PG 1116+215 (zem=0.1765, l=223.36d, b=+68.21d). The semicontinuous coverage of the ultraviolet spectrum over the wavelength range 916-2800 Å provid…
Obscured Activity: AGN, Quasars, Starbursts and ULIGs Observed by the Infrared Space Observatory
Haas, Martin; Klaas, Ulrich; Lutz, Dieter +2 more
Some of the most ‘active’ galaxies in the Universe are obscured by large quantities of dust and emit a substantial fraction of their bolometric luminosity in the infrared. Observations of these infrared luminous galaxies with the Infrared Space Observatory (ISO) have provided a relatively unabsorbed view to the sources fuelling this active emissio…