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Starcounts in the flanking fields of the Hubble Deep Field. The faint end of the disc stellar luminosity function and its scale-height
Mendez, R. A.; Guzman, R.
We present instrumental (F606W, F814W) and calibrated (V, I) photometry and astrometry for point-like sources in the Hubble Deep Field and its flanking fields from combined HST and Keck direct imaging. From this data, a complete sample of stars in the range 18 <= V ~ 25 is derived and compared to the predictions of a galactic structure model. T…
Galaxy Morphology from NICMOS Parallel Imaging
Gardner, Jonathan P.; Teplitz, Harry I.; Heap, Sara R. +1 more
We present high-resolution Near-Infrared Camera and Multiobject Spectrometer images of random fields obtained in parallel to other Hubble Space Telescope observations. We present galaxy number counts reaching H1.6=24. The H1.6-band galaxy counts show good agreement with the deepest I- and K-band counts obtained from ground-ba…
ISO LWS Observations of Cool Evolved Stars and Post-AGB Objects
Barlow, M. J.
Ultraviolet and Optical Studies of Binaries with Luminous Cool Primaries and Hot Companions. V. The Entire IUE Sample
Parsons, Sidney B.; Ake, Thomas B.
We have obtained or retrieved IUE spectra for over 100 middle- and late-type giant and supergiant stars whose spectra indicate the presence of a hot component earlier than type F2. The hot companions are classified accurately by temperature class from their far-UV spectra. The interstellar extinction of each system and the relative luminosities of…
The EC14026 stars - VI. PG1047+003
O'Donoghue, D.; Kilkenny, D.; Lynas-Gray, A. E. +2 more
We report the discovery of rapid oscillations in the sdB star PG1047+003. The oscillations are multiperiodic, with nine periods in the range 104-162s. The optical spectrum of PG1047+003 is consistent with that of a single sdB star. Line profile fitting yields an effective temperature of 35000+/-1000K and log g=5.9+/-0.1, although optical photometr…
Near-Infrared Observations of a Redshift 4.92 Galaxy: Evidence for Significant Dust Absorption
Illingworth, G. D.; Franx, M.; Matthews, K. +2 more
Near-infrared imaging and spectroscopy have been obtained of the gravitationally lensed galaxy at z=4.92 discovered in Hubble Space Telescope (HST) images by Franx et al. Images at 1.2, 1.6, and 2.2 µm show the same arc morphology as the HST images. The spectrum with resolution λ/Δλ~70 shows no emission lines with equivalent width stronger t…
Lensing galaxies: light or dark?
Fassnacht, C. D.; Jackson, N.; Wilkinson, P. N. +4 more
In a recent paper, Hawkins (1997) argues on the basis of statistical studies of double-image gravitational lenses and lens candidates that a large population of dark lenses exists and that these outnumber galaxies with more normal mass-to-light ratios by a factor of 3:1. If correct, this is a very important result for many areas of astronomy inclu…
A Brief History of Recurrent Solar Modulation of the Galactic Cosmic Rays (1937-1990)
Simpson, J. A.
This brief review of the pre-Ulysses era begins with the first measurements by ionization chambers in 1937 of a cosmic ray 27-day intensity variation that was believed to have its origin in recurrent variations of the geomagnetic field. However, with the introduction of neutron monitor analysis of the nucleonic component, it was shown in the 1940s…
A Reanalysis of the Carbon Abundance in the Translucent Cloud Toward HD 24534
Sofia, Ulysses J.; Fitzpatrick, Edward L.; Meyer, David M.
We have reanalyzed the Goddard High Resolution Spectrograph data set presented by Snow et al., which contains the interstellar intersystem C II] λ2325 line through the translucent cloud toward HD 24534 (X Persei). In contrast to the results of Snow et al., we clearly detect the C II] feature at the 3 σ confidence level and measure a C+ …
Spectral analysis of the extreme helium star LSS3184
Heber, U.; Drilling, J. S.; Jeffery, C. S.
LSS3184 is a hydrogen-deficient, early B-type giant, recently found to pulsate with a period of 2.5 hours. Its photospheric parameters have been derived from optical high-resolution spectra by the method of fine analysis. The principal results are T_eff=23300 K, log g=3.35, {n_H}/{n_He}simle0.00015, {n_C}/{n_He}=0.003, {n_N}/{n_He}=0.0005, and {n_…