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ORFEUS II Far-Ultraviolet Observations of the Lunar Atmosphere
Flynn, B.
In 1996 November and December, remote FUV observations of the lunar atmosphere were conducted using the Berkeley spectrograph aboard the ORFEUS-SPAS II satellite. The main goal of the observations was to measure the distribution of Ar above the lunar dayside for the first time and to search for another predicted atmospheric constituent, Ne. During…
Lower bound for electron core beta in the solar wind
Goldstein, Bruce E.; Gary, S. Peter; Newbury, Jennifer A.
Solar wind electrons, especially under conditions of relatively low speed flow, often can be represented as two bi-Maxwellian components, a cooler, more dense core (denoted by the subscript c) and a hotter, more tenuous halo. Solar wind observations from Ulysses between 1.5 and 2 AU further indicate that the β for electron core temperatures parall…
The Chamaeleon infrared nebula revisited. Infrared imaging and spectroscopy of a young stellar object
Henning, Thomas; Feldt, Markus; Lagage, Pierre O. +3 more
We are presenting spectroscopic and imaging data on the Chamaeleon Infrared Nebula (Cha IRN). Imaging was done between 1 and 2.5mu m and at 10mu m. Spectra of the object were obtained in the 2.1mu m - 4.6mu m range by ground-based measurements as well as using ISOPHOT-S in the 2.5mu m - 11.6mu m range. By combining these data with a K-band speckle…
Lyalpha absorbers at z<= 1: HST-CFHT imaging and spectroscopy in the field of 3C 286
Bergeron, J.; Le Brun, V.
We present further observational results on our Lyalpha -only absorber identification project at low and intermediate redshifts. We combine CFHT/MOS imaging and spectroscopic observations of 25 galaxies in the field of the quasar 3C 286 (z_e = 0.849) with HST/FOS spectrum of the quasar between 1600 and 3000 Angstroms and HST/WFPC2 high spatial res…
ISOCAM images at 6.75mu M and 15mu m: the circumnuclear region of NGC4321 (M100)
Martinet, L.; Wozniak, H.; Friedli, D. +1 more
We present ISOCAM images (1.5\arcsec px(-1) ) in the LW2 (6.75mu m) and LW3 (15mu m) broad band filters of the circumnuclear starburst of NGC4321 (M100). A detailed comparison with the emission at other wavelengths (U, B, Hα , and CO) is also presented. The nature and intensity of the mid-infrared emission is shown to be remarkably different from …
Pulsation of the lambda Bootis stars HD 111786 and HD 142994
Paunzen, E.; Matthews, J. M.; Kuschnig, R. +3 more
The detection of possible nonradial pulsation modes among some lambda Bootis stars offers the prospect of using asteroseismology to determine their masses and ages, thereby testing competing theories for the origin of their chemical peculiarities. As a step toward this goal, we conducted multi-site photometric campaigns spanning two weeks each for…
Simultaneous intensive photometry and high resolution spectroscopy of delta Scuti stars. III. Mode identifications and physical calibrations in HD 2724
Mantegazza, L.; Bossi, M.; Nunez, N. S.
On the basis of our new simultaneous photometry and spectroscopy (885 \( uvby \) differential measurements in 11 nights and 154 spectrograms of the FeII\( \lambda \)4508 region in 5 nights), we can detect 12 probable periodicities in the variability pattern of this star, determining the frequencies of 7 without any ambiguity. Through a direct fit …
Ultraviolet Observations of the Hot R Coronae Borealis-Type Star V348 Sagittarii during a Deep Minimum
Clayton, Geoffrey C.; Jeffery, C. S.; Drilling, John S. +1 more
We obtained three high-quality ultraviolet spectra of the hot R Coronae Borealis type star V348 Sgr using the Faint Object Spectrograph of the Hubble Space Telescope (HST). The first of these spectra was obtained when the star was in a shallow minimum (ΔV less than 1 mag), whereas the other two were obtained during a deep minimum (ΔV ~ 6 mag). Whi…
VCC 144: a star-bursting dwarf galaxy in the Virgo cluster
Brosch, N.; Almoznino, E.; Hoffman, G. Lyle
We describe results of a multi-spectral study of a blue compact dwarf galaxy in the Virgo Cluster. The object was observed with broad-band and Hα imaging, ultraviolet observations, and radio synthesis. Our data were combined with previously published optical observations, with HI single-beam observation and with far-infrared data, and were compare…
Bayesian image reconstruction with space-variant noise suppression
Nunez, J.; Llacer, J.
In this paper we present a Bayesian image reconstruction algorithm with entropy prior (FMAPE) that uses a space-variant hyperparameter. The spatial variation of the hyperparameter allows different degrees of resolution in areas of different statistical characteristics, thus avoiding the large residuals resulting from algorithms that use a constant…