Search Publications
Missions
Journals
Publication Years
The mid infrared spectrum of the hyperluminous galaxies IRAS F15307+3252 and the Cloverleaf
Aussel, H.; Boulanger, F.; Gerin, M. +4 more
We report the detections of the hyperluminous galaxy IRAS F15307 +3252 at z = 0.93 and of the Cloverleaf quasar, H 1413+117 at z = 2.56, in the mid infrared using ISOCAM. The spectrum near 10 microns (observed wavelength) joins smoothly with the data taken from the ground or with the IRAS satellite. We have detected none of the infrared features a…
Hubble Space Telescope Observations of Planetary Nebulae in the Magellanic Clouds. VII. Cycle 3 and Archive Narrowband [O III] 500.7 nanometer Imaging
Ford, H. C.; Harrington, J. P.; Wood, P. R. +6 more
We present the continuation of our analysis of narrowband [O III] images, obtained using the Hubble Space Telescope (HST), of planetary nebulae (PNs) in the Magellanic Clouds. Six objects, five in the Large Magellanic Cloud, are observed as part of the General Observer program. An additional 15 objects are retrieved from the HST archive. The major…
Radio Emission from Young Stellar Objects near LkHα 101
Stine, Peter C.; O'Neal, Douglas
We present results of a VLA 3.6 cm B-configuration study of a region around the Herbig Be star LkHα 101. We detect 16 sources down to 5 sigma (rms) thresholds of 0.25 mJy. Most of the sources are thought to be young stellar objects associated with the star formation region. Six of the objects have optical counterparts, and at least two are weak-li…
Coronal Scale-Height Enhancement by Magnetohydrodynamic Waves
Rosner, R.; Litwin, C.
We discuss the possibility that the transmission of Alfvén waves from the photosphere into coronal loops can increase the density scale height in these loops. The mechanism involved is the ponderomotive force of transmitted waves, which opposes the force of gravity. We propose that this effect may account for cool coronal loops observed by the Sol…
Interstellar Matter and the Boundary Conditions of the Heliosphere
Frisch, Priscilla C.
The interstellar cloud surrounding the solar system regulates the galactic environment of the Sun, and determines the boundary conditions of the heliosphere. Both the Sun and interstellar clouds move through space, so these boundary conditions change with time. Data and theoretical models now support densities in the cloud surrounding the solar sy…
An Empirical Limit on Extremely High Redshift Galaxies
Lanzetta, Kenneth M.; Yahil, Amos; Fernández-Soto, Alberto
We apply the Lyman absorption signature to search for galaxies at redshifts z ~ 6-17 using optical and infrared images of the Hubble Deep Field. The infrared images are sensitive to a point-source 5 sigma detection threshold of AB(22,000) = 23.8, which, adopting plausible assumptions to relate rest-frame ultraviolet flux densities to unobscured st…
In Situ Measurements of Interstellar Dust
Grün, E.; Landgraf, M.
We present the mass distribution of interstellar grains measured in situ by the Galileo and Ulysses space probes as cumulative flux. The derived in situ mass distribution per logarithmic size interval is compared to the distribution determined by fitting extinction measurements. Large grains measured in situ contribute significantly to the overall…
The solar neighbourhood HR diagram as a quantitative test for evolutionary time scales
Schroeder, K. -P.
The HIPPARCOS parallaxes have provided us with a precise HR diagram (HRD) of the solar neighbourhood, complete within certain limits. The scope of this work is a study of the stellar population densities in characteristic regions of the HRD to test stellar evolutionary time scales. We examine two HRDs (M_v <= 4.0), both based on the single-star…
Recovery of 29 Second Oscillations in Hubble Space Telescope Eclipse Observations of the Cataclysmic Variable UX Ursae Majoris
Horne, Keith; Long, Knox S.; Baptista, Raymundo +3 more
Low-amplitude (~=0.5%) 29 s oscillations have been detected in Hubble Space Telescope Faint Object Spectrograph eclipse observations of the nova-like cataclysmic variable UX UMa. These are the same dwarf nova-type oscillations that were originally discovered in this system by Warner & Nather in 1972. The 29 s oscillations are seen in one pair …
The Orbits of the Inner Uranian Satellites from Hubble Space Telescope and Voyager 2 Observations
Jacobson, R. A.
This article presents revised orbital elements for the 10 small Uranian satellites discovered by the Voyager 2 spacecraft. The elements have been determined from a fit to astrometric observations made with the Hubble Space Telescope and imaging data acquired by Voyager 2. An assessment of the accuracy of the orbits represented by the elements is p…