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The Near-Infrared Broad Emission Line Region of Active Galactic Nuclei. I. The Observations
We present high-quality (high signal-to-noise ratio and moderatespectral resolution) near-infrared (near-IR) spectroscopic observationsof 23 well-known broad emission line active galactic nuclei (AGNs). Inaddition, we obtained simultaneous (within 2 months) opticalspectroscopy of similar quality. The near-IR broad emission linespectrum of AGNs is dominated by permitted transitions of hydrogen,helium, oxygen, and calcium, and by the rich spectrum of singly ionizediron. In this paper we present the spectra, line identifications, andmeasurements, and we address briefly some of the important issuesregarding the physics of AGN broad emission line regions. In particular,we investigate the excitation mechanism of neutral oxygen and confrontfor the first time theoretical predictions of the near-IR iron emissionspectrum with observations.
| The Spacelab-1 Very Wide Field Survey of UV-excess objects. IV. The performance of the instrument in combination with optical photometry as a means of identifying stars with peculiar properties.
UV (195 nm) and Stroemgren uvby photometry of a 110 square degree fieldat high southern galactic latitudes are analyzed through a comparison ofi) UV magnitudes for 57 stars of various types common to the publishedTD1 catalogue and the Very Wide Field Camera (VWFC); and ii) observedand theoretical two-colour diagrams. The higher sensitivity of the VWFC(=~0.5magnitude) and its more complete survey are exemplified by thedetection and UV measurement of a series of objects with moderateUV-excess in addition to detection of some very blue objects of variousnature down to fainter than 12th magnitude in the optical domain. Adeeper survey with a VWFC-type instrument could provide a completesample for studies of the group properties of faint blue stars. Duringthe uvby reductions it was found that the usual procedure of plottingresiduals as functions of declination, hour angle and airmass can be apowerful and diagnostic test of photometer rigidity.
| Observation of Occultations at Skalnaté Pleso Observatory During the Years 1950-1953
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Membro dei seguenti gruppi:
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Osservazione e dati astrometrici
| Costellazione: | Acquario |
| Ascensione retta: | 21h25m24.91s |
| Declinazione: | -14°16'38.4" |
| Magnitudine apparente: | 6.836 |
| Distanza: | 555.556 parsec |
| Moto proprio RA: | 13.5 |
| Moto proprio Dec: | -1.6 |
| B-T magnitude: | 6.906 |
| V-T magnitude: | 6.842 |
Cataloghi e designazioni:
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