Search Publications
Detection of the 62 Micron Crystalline H2O Ice Feature in Emission toward HH 7 with the Infrared Space Observatory Long-Wavelength Spectrometer
Ceccarelli, Cecilia; Giannini, Teresa; Nisini, Brunella +4 more
We report the detection of the 62 µm feature of crystalline water ice in emission toward the bow-shaped Herbig-Haro object HH 7. Significant amounts of far-infrared continuum emission are also detected between 10 and 200 µm, so that Herbig-Haro objects cease to be pure emission-line objects at far-infrared wavelengths. The formation of…
Infrared Space Observatory Observations of Far-Infrared Rotational Emission Lines of Water Vapor toward the Supergiant Star VY Canis Majoris
Feuchtgruber, Helmut; Neufeld, David A.; Melnick, Gary J. +1 more
We report the detection of numerous far-infrared emission lines of water vapor toward the supergiant star VY Canis Majoris. A 29.5-45 µm grating scan of VY CMa, obtained using the Short-Wavelength Spectrometer (SWS) of the Infrared Space Observatory at a spectral resolving power λ/Δλ of ~2000, reveals at least 41 spectral features due to wat…
On the Nuclear Rotation Curve of M31
Statler, Thomas S.
The currently favored model for the double nucleus of M31 consists of an eccentric disk with an off-center density concentration caused by stars lingering at the apocenters of their orbits about the central black hole. If such a disk is to be in equilibrium, the requirement that it precess uniformly because of self-gravity imposes a characteristic…
Objects in NGC 205 Resolved into Stellar Associations by Hubble Space Telescope Ultraviolet Imaging
Cappellari, Michele; Renzini, Alvio; Greggio, Laura +3 more
We have obtained high-resolution UV images with the Hubble Space Telescope/Wide-Field Planetary Camera 2 of the central region of the dwarf elliptical galaxy NGC 205. Our images reveal that many of the hot UV stars previously detected and studied from the ground are actually multiple systems, open clusters, and star associations. We have performed…
The Host Galaxy of the Broad Absorption Line QSO PG 1700+518 and Its Ring Galaxy Companion: NICMOS 1.6 Micron Imaging
Hines, Dean C.; Thompson, Rodger I.; Weymann, Ray J. +2 more
The 1.6 µm Near Infrared Camera and Multiobject Spectrometer image of the broad absorption line QSO PG 1700+518 clearly resolves the QSO host galaxy and a ringlike companion. The companion is most likely a ring galaxy produced in a collision with the QSO galaxy ~5×107 yr ago. The morphology of the PG 1700+518 system is very simila…
A Precision Test of HIPPARCOS Systematics toward the Hyades
Gould, Andrew; Narayanan, Vijay K.
We propose a test that can in principle detect any systematic errors in the Hipparcos parallaxes toward the Hyades cluster at the level of 0.3 mas. We show that the statistical parallax algorithm subsumes the classical moving cluster methods and provides more precise estimates of the distance and the first two moments of the velocity distribution …
The Color Distributions of Globular Clusters in Virgo Elliptical Galaxies
Tsvetanov, Zlatan I.; Neilsen, Eric H., Jr.
This Letter presents the color distributions of the globular cluster (GC) systems of 12 Virgo elliptical galaxies, measured using data from the Hubble Space Telescope. Bright galaxies with large numbers of detected GCs show two distinct cluster populations with mean V-I colors near 1.01 and 1.26. The GC population of M86 is a clear exception; its …
NGC 3516: The Long-Term Variability of the Active Galactic Nucleus Emission-Line and Absorption-Line Regions
Koratkar, A. P.; Korista, K. T.; O'Brien, P. T. +3 more
NGC 3516 displays the strongest intrinsic blueshifted UV absorption lines of any Seyfert 1 galaxy. In this paper, we report on UV spectrophotometric monitoring data obtained over a period of 11 months using the Hubble Space Telescope Faint Object Spectrograph (HST/FOS). The observations were at ~2 Å resolution and covered the wavelength range 1150…
Detection of Surface Brightness Fluctuations in NGC 4373 Using the Hubble Space Telescope
Casertano, Stefano; Ballester, Gilda E.; Dressler, Alan +16 more
Surface brightness fluctuations (SBF) have been detected for three elliptical galaxies--NGC 3379 in the Leo group, NGC 4406 in the Virgo cluster, and NGC 4373 in the Hydra-Centaurus supercluster--using marginally sampled, deep images taken with the Planetary Camera of the WFPC2 instrument on the Hubble Space Telescope (HST). The power spectrum of …
A Photometric Investigation of the GRB 970228 Afterglow and the Associated Nebulosity
Castander, Francisco J.; Lamb, Donald Q.
We carefully analyze the WFPC2 and STIS images of GRB 970228. We measure magnitudes for the GRB 970228 point-source component in the WFPC2 images of (V=26.20+0.14-0.13, Ic=23.94+0.10-0.09) and (V=26.52+0.16-0.18, Ic=24.31+0.15-0.11) on Mar…