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Possible discovery of threeγ-ray pulsars
Yu, K. N.; Young, E. C. M.; Lu, Tan +1 more
The possible discovery of threeγ-ray pulsars 0656 + 14, 0950 + 08, and 1822 - 09 based on COS-B data analysis is reported. Their light curves, the other related features, and the methods leading to these results are also given. Among these three pulsars, PSR 0656 + 14 is the most significant one for being aγ-ray pulsar.
The Starburst model for the optical variability of the Seyfert 1 galaxies NGC 4151 and NGC 5548
Aretxaga, Itziar; Terlevich, Roberto
In the frame of the Starburst model, we show that the stellar processes expected to occur during the evolution of a metal rich massive stellar cluster can reproduce the observed optical light curves of the Seyfert 1 galaxies NGC 4151 and NGC 5548.
A Thick Reflection Nebula Illuminated by a Power Law
Binette, Luc; Martin, Peter; Magris C., Gladis
We present the results of modelling the energy distribution of a power law reflected by a dusty cloud. We explore in a fully consistent manner the case in which the reflecting nebula is of considerable optical depth. We apply the model to the observations of the detached emission line cloud at 8 kpc from the nucleus of Pks 2152-69 for whichcontinu…
A development of double star astronomy after Hipparcos
Lampens, P.; Dommanget, J.
Now that the HIPPARCOS satellite safely revolves on his 'degraded' orbit - after the exploit of the ESA technicians to rescue it from the faulty ignition of its apogeum boost motor - and regularly provides the information needed for reaching the initial aim of the project, one may turn to examine the possible applications of the finalHipparcos Cat…
Are PSR 0656+14, PSR 0950+08, and PSR 1822-09 gamma-ray pulsars?
Brown, Lawrence E.; Hartmann, Dieter H.
The possible discovery of three new γ-ray pulsars PSR 0656+14, PSR 0950+08, and PSR 1822-09 (Ma, Lu, Yu, and Young, 1993) in data obtained with the COS-B experiment is reinvestigated using a refined technique for pulsar light curve analysis. The results of this study do not confirm the previously claimed γ-ray pulsar nature of any of these pulsars…
X-Ray Ultraviolet and Far Infrared Emission of Seyfert Galaxies
Mas-Hesse, J. M.; Rodriguez-Pascual, P. M.; Mirabel, I. F. +3 more
We have compiled multiwavelength data (in the radio, FIR, optical, UV and X-ray ranges) for a sample of 126 galaxies, including QSO, Seyfert 1, Seyfert 2 and galaxies dominated by star-forming processes. We have tested the implications of "unified Seyfert models", which assume that Seyfert 1 and 2 galaxies are intrinsically the same kind of object…
The Ultraviolet Spectrum of the Binary System Ty-Pyxidis
Danezis, E.; Theodossiou, E.; Antonopoulou, E.
A detailed list and analysis of line identifications of five UV spectra of the RS CVn-type binary system TY Pyxidis are presented. These spectra are recorded at different phases with the International Ultraviolet Explorer (IUE). Two of them are in the wavelength rangeλλ1235–1950 Å while the other three in the rangeλλ2700–3110 Å. The far-UV spectru…
Theoretical Modes Fitting on Miras Light Curves
Barthes, D.; Mennessier, M. O.; Mattei, J. A. +1 more
Visual observations of long period variable stars over 20 years were provided by the American Association of Variable Stars Observers (AAVSO), and were analyzed as part of the preparation of the HIPPARCOS mission. A set of frequencies is extracted from the light curve by using Fourier transform, preliminary Van Cittert deconvolution and comparison…