Results 281 to 290 of about 289,816 (297)

The multiwavelength behaviour of BL Lacertae explained by a wiggling filamentary jet

Raiteri C.
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Feedback mechanisms stopping the star formation in a pair of massive galaxies in the early Universe

Pérez-González P, D'Eugenio F, Pino BRD, Perna M, Uebler H, Maiolino R, Arribas S, Lamperti I, Bunker A, Carniani S, Charlot S, Willott C, Böker T, Parlanti E, Scholtz J, Venturi G, Barro G, Costantin L, Navarro IM, Dunlop J, Magee D, Cresci G.   +21 more
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The X-Ray Spectra of Active Galactic Nuclei

Physica Scripta, 1984
Recent observations of the X-ray spectra of active galactic nuclei are reviewed. After an outline of the properties of these sources deduced from observations at other wavelengths, the relevance of X-ray spectra to our understanding of the X-ray emission mechanisms and of the ultimate source of energy is discussed.
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X-rays from active galactic nuclei ? Hard component

Space Science Reviews, 1981
It is now well known that X-ray emission in active galactic nuclei (AGN) is a fairly common phenomenon (see M.J. Rees’s review in this volume). By examining the recent observational information from Ariel V, HEAO-1, and the Einstein Observatory, we have reached the conclusion (Tsuruta 1981) that the following interpretation may be used as a relevant ...
S. Ichimaru, Sachiko Tsuruta, F. Takahara   +2 more
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Limits of X-ray variability in active galactic nuclei

Nature, 1986
A significant correlation is demonstrataed here between the X-ray luminosity and the timescale of X-ray variability for Seyfert galaxies and quasars. This is interpreted as evidence that the emitting plasma is near the limit of being dominated by electron-positron pairs.
R. F. Mushotzky, P. Barr
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The X-ray variability of active galactic nuclei

2008
Recent results relating to the X-ray variability exhibited by active galactic nuclei are reviewed. EXOSAT observations have established, contrary to earlier indications, that X-ray variability on a timescale of an hour or less is a relatively common feature of such sources.
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X-Ray Variability in Active Galactic Nuclei

1998
X-ray variability is a distinguishing property of Active Galactic Nuclei (AGN), and the energetics and time scales of the emission dictate that the X-rays must originate very close to the central engine. In this review I discuss two basic topics from AGN variability research.
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X-Ray Spectra of Active Galactic Nuclei

1980
There are a variety of galaxies which are classified as nuclearactive, ranging from those which have nuclei which are merely distinguishable from a stellar component all the way to QSO’s. The subject of this lecture will be only those extreme cases (Seyfert I, BL Lac and quasar) which constitute the most intense compact X-ray sources which are ...
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