Search Publications
The Complex Protostellar Source IRAS 04325+2402
Hartmann, Lee; Calvet, Nuria; Jayawardhana, Ray +2 more
We report Hubble Space Telescope near-infrared NICMOS observations of a remarkable low-luminosity Class I (protostellar) source in the Taurus Molecular Cloud. IRAS 04325+2402 exhibits a complex bipolar scattered light nebula. The central continuum source is resolved and may be multiple, or it may be crossed by a small dust lane. Complex arcs seen …
Polarized Narrow-Line Emission from the Nucleus of NGC 4258
Filippenko, Alexei V.; Ho, Luis C.; Barth, Aaron J. +5 more
The detection of polarized continuum and line emission from the nucleus of NGC 4258 by Wilkes et al. in 1995 provides an intriguing application of the unified model of Seyfert nuclei to a galaxy in which there is known to be an edge-on, rotating disk of molecular gas surrounding the nucleus. Unlike most Seyfert nuclei, however, NGC 4258 has strong…
Deep Near-Infrared Images and ISOCAM Observations of Chamaeleon I North
Olofsson, G.; Roth, M.; Nordh, L. +3 more
We present the results of deep near-infrared imaging and ISOCAM observations of three selected regions localized in the northern part of the Chamaeleon I dark cloud, in order to search for the low-luminosity population. In an area of 3x3 arcmin^2 centered on the bipolar molecular outflow, which is the densest part of the cloud, we have discovered …
A Near-Infrared Stellar Census of the Blue Compact Dwarf Galaxy VII ZW 403
Greggio, Laura; Hopp, Ulrich; Schulte-Ladbeck, Regina E. +1 more
We present near-infrared single-star photometry for the low-metallicity blue compact dwarf galaxy VII Zw 403. We achieve limiting magnitudes of F110W~25.5 and F160W~24.5 using one of the NICMOS cameras with the Hubble Space Telescope equivalents of the ground-based J and H filters. The data have a high photometric precision (0.1 mag) and are more …
Ultraviolet Spectral Classification of O and B Stars in the Large Magellanic Cloud
Bruhweiler, Frederick C.; Smith Neubig, Margaret M.
In this extension of our previous ultraviolet classification study of Small Magellanic Cloud stars, we construct an ultraviolet classification system for stars of the Large Magellanic Cloud, a galaxy with a metallicity intermediate to those of the Milky Way and the SMC. Employing the same method as was used for the SMC, we compile a set of LMC spe…
High-Velocity Line Emission in the Narrow-Line Region of NGC 4151
Gull, T. R.; Kraemer, S. B.; Crenshaw, D. M. +6 more
Narrowband imaging of the nuclear region of NGC 4151 with the Hubble Space Telescope is presented. The filter bandpasses isolate line emission in various high-velocity ranges in several ions. Slitless and long-slit spectra of the region with the Space Telescope Imaging Spectrograph also indicate the locations of high-velocity gas. These emission r…
A Large H I Shell surrounding the Wolf-Rayet Star HD 191765
St-Louis, Nicole; Gervais, Simon
We have surveyed a 2.6dx2.6d field centered on the Wolf-Rayet (W-R) star HD 191765 (=WR 134) in the H I 21 cm line and in the 1420 and 408 MHz radio continuum, using the Synthesis Telescope of the Dominion Radio Astrophysical Observatory, to search for direct evidence of the interaction between the W-R star wind and the interstellar medium. An arc…
HUBBLE SPACE TELESCOPE Images of the Compact Nebula around RY Scuti
Smith, Nathan; Gehrz, Robert D.; Humphreys, Roberta M. +3 more
We present HST Wide Field Planetary Camera 2 images of the very massive eclipsing binary RY Scuti. The HST Hα image shows a very complex ionized nebula roughly 1" in size. Several interesting structures are revealed, including what appears to be a pair of concentric ionized rings above and below the equatorial plane of the system, located at the i…
Quasar Candidates in the Hubble Deep Field
Martini, Paul; Conti, Alberto; Kennefick, Julia D. +1 more
The Hubble Deep Field (HDF) gives us an unprecedented view of our universe and an opportunity to study a wide range of questions in galaxy evolution and cosmology. Here we focus on the search for unresolved faint quasars and active galactic nuclei (AGNs) in the crude combine images using a multicolor imaging analysis that has proved very successfu…
CTQ 414: A New Gravitational Lens
Dressler, Alan; Winn, Joshua N.; Morgan, Nicholas D. +2 more
We report the discovery and ground-based observations of the new gravitational lens CTQ 414. The source quasar lies at a redshift of z=1.29 with a B magnitude of 17.6. Ground-based optical imaging reveals two point sources separated by 1.2" with a magnitude difference of roughly 1 mag. Subtraction of two stellar point-spread functions from images …