Search Publications
Hubble Space Telescope Observations of Vibrationally Excited Molecular Hydrogen in Cluster Cooling Flow Nebulae
Mack, Jennifer; Donahue, Megan; Voit, G. Mark +3 more
We report the results of Hubble Space Telescope near-infrared camera and multiobject spectrometer and Wide Field Planetary Camera 2 imaging of emission-line nebulae in the central galaxies of three clusters of galaxies purported to host massive cooling flows: Perseus (NGC 1275), Abell 2597, and PKS 0745-191. The spectral signature of vibrationally…
WFPC2 Images of a Face-on Disk Surrounding TW Hydrae
Ménard, François; Krist, John E.; Stapelfeldt, Karl R. +2 more
Hubble Space Telescope observations of the isolated T Tauri star TW Hydrae reveal the presence of a compact circumstellar nebula. After subtraction of a reference point-spread function (PSF), a smooth, symmetrical, circular halo can be seen in both R- and I-band WFPC2 images. Its intensity declines with radius until reaching an outer sensitivity l…
Preliminary Spectral Analysis of the Type II Supernova 1999EM
Filippenko, Alexei V.; Kirshner, R. P.; McCray, R. +19 more
We have calculated fast direct spectral model fits to two early-time spectra of the Type II plateau SN 1999em, using the SYNOW synthetic spectrum code. The first is an extremely early blue optical spectrum and the second a combined Hubble Space Telescope and optical spectrum obtained one week later. Spectroscopically this supernova appears to be a…
High-Resolution Optical/Near-Infrared Imaging of Cool Ultraluminous Infrared Galaxies
Sanders, D. B.; Evans, A. S.; Surace, Jason A.
We present high spatial resolution (FWHM~0.3"-0.8") BIHK'-band imaging of a sample of ultraluminous infrared galaxies (Lir>1012 Lsolar ULIGs) with ``cool'' mid-infrared colors (f25µm/f60µm<0.2), which select against active galactic nucleus-like (AGN-like) systems, …
The X-Ray Transient XTE J1118+480: Multiwavelength Observations of a Low-State Minioutburst
Chaty, S.; Cui, W.; Shrader, C. R. +3 more
We present multiwavelength observations of the newly discovered X-ray transient XTE J1118+480 obtained in the rising phase of the 2000 April outburst. This source is located at unusually high Galactic latitude and in a very low absorption line of sight. This made the first Extreme Ultraviolet Explorer (EUVE) spectroscopy of an X-ray transient outb…
The Optical Gravitational Lensing Experiment Monitoring of QSO 2237+0305
Alard, C.; Udalski, A.; Woźniak, P. R. +4 more
We present results from 2 yr of monitoring of Huchra's lens (QSO 2237+0305) with the 1.3 m Warsaw telescope on Las Campanas, Chile. Photometry in the V band was done using a newly developed method for image subtraction. Reliable subtraction without Fourier division removes all complexities associated with the presence of a bright lensing galaxy. W…
Double-peaked Broad Emission Lines in NGC 4450 and Other LINERS
Filippenko, Alexei V.; Ho, Luis C.; Shields, Joseph C. +5 more
Spectra taken with the Hubble Space Telescope (HST) reveal that NGC 4450 emits Balmer emission lines with displaced double peaks and extremely high velocity wings. This characteristic line profile, previously seen in a few nearby LINERs and in a small fraction of broad-line radio galaxies, can be interpreted as a kinematic signature of a relativis…
Extreme Star Formation in the Interacting Galaxy Arp 299 (IC 694+NGC 3690)
Rieke, George H.; Alonso-Herrero, Almudena; Rieke, Marcia J. +1 more
We present a comprehensive study of the star formation properties of the infrared luminous galaxy Arp 299 (IC 694+NGC 3690). The observations include Hubble Space Telescope (HST) NICMOS imaging and Multiple Mirror Telescope optical and near-infrared spectroscopy together with HST archival data. We correct the galaxy parameters for extinction and u…
2-45 Micron Infrared Spectroscopy of Carbon-rich Proto-Planetary Nebulae
Volk, Kevin; Kwok, Sun; Hrivnak, Bruce J.
Infrared Space Observatory (ISO) 2-45 µm observations of seven proto-planetary nebulae (PPNs) and two other carbon-rich objects are presented. The unidentified emission features at 21 and 30 µm are detected in six sources, including four new detections of the 30 µm feature. This previously unresolved 30 µm feature is now re…
Evidence for Multiple Mergers among Ultraluminous Infrared Galaxies: Remnants of Compact Groups?
Lucas, Ray A.; Colina, Luis; Bushouse, Howard +1 more
In a large sample of ultraluminous infrared galaxies (ULIRGs) imaged with the Hubble Space Telescope, we have identified a significant subsample that shows evidence for multiple mergers. The evidence is seen among two classes of ULIRGs: (1) those with multiple remnant nuclei in their core, sometimes accompanied by a complex system of tidal tails, …