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Evidence for water vapor in Titan's atmosphere from ISO/SWS data
de Graauw, Th.; Kessler, M. F.; Lellouch, E. +6 more
The infrared spectrum of Titan around 40 mu m was recorded in the grating mode of the Short Wavelength Spectrometer (SWS) of ISO, with a resolving power of about 1900. Two emission features appear at 43.9 and 39.4 mu m, where pure rotational water lines are expected. Line strengths are about 8 times the 1sigma statistical noise level. The H_2O ver…
Spheroid Luminosity and Mass Functions from Hubble Space Telescope Star Counts
Gould, Andrew; Bahcall, John N.; Flynn, Chris
We analyze 166 spheroid subdwarfs (6.5 < MV < 14.5) found in 53 fields observed with the Wide Field Planetary Camera on the Hubble Space Telescope. The fields cover 221 arcmin2 over a wide range of directions. The spheroid luminosity function (LF) is inconsistent at about the 3 σ level with the local spheroid LF of Dahn…
Coronal Composition above the Solar Equator and the North Pole as Determined from Spectra Acquired by the SUMER Instrument on SOHO
Schühle, U.; Feldman, U.; Laming, J. M. +1 more
Using spectra obtained by the SUMER instrument on the Solar and Heliospheric Observatory (SOHO) we have determined the composition of the bulk of the coronal plasma in the vicinity of the solar surface over a polar coronal hole and an equatorial region. Our measurements show that although low first ionization potential (FIP) elements are enriched …
HSTcolour-magnitude diagrams of six old globular clusters in the LMC
Suntzeff, N. B.; Walker, A. R.; Mateo, M. +4 more
We report on HST observations of six candidate old globular clusters in the Large Magellanic Cloud (LMC): NGC 1754, 1835, 1898, 1916, 2005 and 2019. Deep exposures with the F555W and F814W filters provide us with colour-magnitude diagrams that reach to an apparent magnitude in V of ~25, well below the main-sequence turn-off. These particular clust…
WFPC2 Observations of Star Clusters in the Magellanic Clouds. II. The Oldest Star Clusters in the Small Magellanic Cloud
Sarajedini, Ata; Mighell, Kenneth J.; French, Rica S.
We present our analysis of archival Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) observations in F450W (~B) and F555W (~V) of the intermediate-age populous star clusters NGC 121, NGC 339, NGC 361, NGC 416, and Kron 3 in the Small Magellanic Cloud. We use published photometry of two other SMC populous star clusters, Lindsay 1 and Li…
Keck Spectroscopy and NICMOS Photometry of a Redshift Z = 5.60 Galaxy
Bunker, Andrew; Spinrad, Hyron; Stern, Daniel +4 more
We present Keck Low Resolution Imaging Spectrometer spectroscopy along with Near-Infrared Camera and Multiobject Spectrometer (NICMOS) F110W (~J) and F160W (~H) images of the galaxy HDF 4-473.0 in the Hubble Deep Field (HDF), with a detection of an emission line consistent with Lyα at a redshift of z=5.60. Attention to this object as a high-redshi…
Laboratory identification of the 4.62mu M solid state absorption band in the ISO-SWS spectrum of RAFGL 7009S
Heras, A. M.; Dartois, E.; Demyk, K. +3 more
We focus on the problem of the assignment of the ``XCN'' solid state feature observed in the spectra of numerous protostellar objects. This feature, located at 4.62µm has been tentatively identified with the molecular ion OCN(-) . New laboratory experiments have been performed in order to confirm this identification. OCN(-) is produced by UV…
Helioseismic Measurements of the Subsurface Meridional Flow
Braun, D. C.; Fan, Y.
We measure the mean frequencies of acoustic (p-mode) waves propagating toward and away from the poles of the Sun from observations made with the Solar Oscillations Investigation-Michelson Doppler Imager on board the Solar and Heliospheric Observatory and the ground-based Global Oscillations Network Group. We demonstrate that there is a significant…
Ion Temperatures in a Solar Polar Coronal Hole Observed by SUMER on SOHO
Wilhelm, K.; Tu, C. -Y.; Marsch, E. +1 more
The temperatures of some highly charged ions in the southern solar polar coronal hole are determined from the widths of the extreme ultraviolet (EUV) lines measured by the SUMER (Solar Ultraviolet Measurements of Emitted Radiation) instrument on SOHO (Solar and Heliospheric Observatory). Radiation from both light ions, such as Ne6+, Ne<…
ISO deep far-infrared survey in the ``Lockman Hole''. A search for obscured objects at high redshift. I. Observations
Sanders, D. B.; Kawara, K.; Taniguchi, Y. +11 more
Two 44arcmin x 44arcmin fields in the Lockman Hole were mapped at 95 mu m and 175 mu m using ISOPHOT. A simple program code combined with PIA works well to correct for drift in the detector responsivity. The number density of 175 mu m sources is 3-10 times higher than expected from the no-evolution model. Based on observations with ISO, an ESA pro…