Search Publications
Very Long Lived Wave Patterns Detected in the Solar Surface Velocity Signal
Ulrich, Roger K.
The wavelike pattern of velocity variations in the outer layers of the Sun known as the ``torsional oscillations'' is shown to consist of long-lived inertial oscillation waves. The dominant pattern which was first identified at Mount Wilson and which has now been observed with the Michelson Doppler Imager instrument and the Global Oscillation Netw…
The Broad-Line and Narrow-Line Regions of the LINER NGC 4579
Filippenko, Alexei V.; Ho, Luis C.; Rix, Hans-Walter +2 more
We report the discovery of an extremely broad Hα emission line in the LINER nucleus of NGC 4579. From ground-based observations, the galaxy was previously known to contain a type 1 nucleus with a broad Hα line of FWHM~2300 km s-1 and FWZI~5000 km s-1. New spectra obtained with the Hubble Space Telescope (HST) and a 0.2" wide …
The Interstellar Medium of Star-forming Irregular Galaxies: The View with ISO
Dale, Daniel A.; Hunter, Deidre A.; Rubin, Robert H. +8 more
We present mid-infrared imaging and far-infrared (FIR) spectroscopy of five IBm galaxies observed by ISO as part of our larger study of the interstellar medium of galaxies. Most of the irregulars in our sample are very actively forming stars, and one is a starburst system. Thus, most are not typical Im galaxies. The mid-infrared imaging was in a b…
NICMOS Imaging of the Host Galaxies of z ~ 2-3 Radio-quiet Quasars
Heckman, Timothy M.; Calzetti, Daniela; Ridgway, Susan E. +1 more
We have made a deep NICMOS imaging study of a sample of five z~2-3 radio-quiet quasars with low absolute nuclear luminosities, and we have detected apparent host galaxies in all of these. Most of the hosts have luminosities approximately equal to present-day L*, with a range from 0.2L* to about 4L*. These host gala…
The Galaxy Population of Cluster RX J0848+4453 at Z=1.27
Dickinson, M.; van Dokkum, P. G.; Stanford, S. A. +3 more
We present a study of the galaxy population in the IR-selected cluster RX J0848+4453 at z=1.27, using deep Hubble Space Telescope (HST) NICMOS HF160W and WFPC2 IF814W images of the cluster core. We morphologically classify all galaxies to Ks=20.6 that are covered by the HST imaging and determine photometric redshif…
Quiescent Giant Molecular Cloud Cores in the Galactic Center
Li, Y.; Lis, D. C.; Zylka, R. +1 more
We have used the Long Wavelength Spectrometer aboard the Infrared Space Observatory to map the far-infrared continuum emission (45-175 µm) toward several massive giant molecular cloud (GMC) cores located near the Galactic center. The observed far-infrared and submillimeter spectral energy distributions imply low temperatures (~15-22 K) for t…
Chandra, EUVE, HST, and VLA Multiwavelength Campaign on HR 1099: Instrumental Capabilities, Data Reduction, and Initial Results
Ayres, Thomas R.; Brown, Alexander; Drake, Jeremy J. +4 more
In mid-September of 1999, a multiwavelength campaign was carried out on the coronally active RS Canum Venaticorum binary HR 1099 (K1 IV+G5 V P=2.84 days), during commissioning of the High Energy Transmission Grating Spectrometer (HETGS) of the Chandra X-ray Observatory (CXO). The coordinated program involved the Extreme Ultraviolet Explorer (EUVE)…
Space Telescope Imaging Spectrograph Echelle Observations of the Seyfert Galaxy NGC 4151: Physical Conditions in the Ultraviolet Absorbers
Gull, T. R.; Kraemer, S. B.; Crenshaw, D. M. +7 more
We have examined the physical conditions in intrinsic UV-absorbing gas in the Seyfert galaxy NGC 4151, using echelle spectra obtained with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope on 1999 July 19. We confirm the presence of the kinematic components detected in earlier Goddard High Resolution Spectrograph (GHRS)…
The Southern Crab from a New Perspective
Livio, Mario; Corradi, Romano L. M.; Munari, Ulisse +2 more
New Hubble Space Telescope images and Cerro Tololo Inter-American Observatory echelle spectra of the nebula around the symbiotic Mira Henize 2-104 are presented. The nebula consists of two nested hourglass-shaped structures and a collimated polar jet. Spatiokinematical modeling shows that all three outflows were ejected during approximately the sa…
Coronal Mass Ejection of 2000 July 14 Flare Event: Imaging from Near-Sun to Earth Environment
Pick, M.; Kaiser, M. L.; Ipavich, F. M. +6 more
We report the results of our investigation of interplanetary effects caused by the large solar flare (X5.7/3B) that occurred on 2000 July 14. In association with this event a bright, fast, halo coronal mass ejection (CME) was observed. The analysis of multiwavelength, high-cadence images obtained from the Nançay Radioheliograph shows the on-disk s…