NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-06-16 T20:21:45 PDT
Help | Comment | NED Home

For refcode 1993ApJ...402..432K:
Retrieve 5 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
1993ApJ...402..432K X-RAY LIGHT CURVES OF ACTIVE GALACTIC NUCLEI ARE PHASE INCOHERENT JULIAN KROLIK Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 CHRIS DONE HAS/NRC Research Associate, Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center AND GRZEGORZ MADEJSKI Universities Space Research Association, Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center, Code 666, Greenbelt, MD 20771 Received 1992 March 6; accepted 1992 July 16 ABSTRACT We compute the Fourier phase spectra for the light curves of five low- luminosity active galactic nuclei observed by EXOSAT. There is no statistically significant phase coherence in any of them. This statement is equivalent, subject to a technical caveat, to a demonstration that their fluctuation statistics are Gaussian. Models in which the X-ray output is controlled wholly by a unitary process undergoing a nonlinear limit cycle are therefore ruled out, while models with either a large number of randomly excited independent oscillation modes or nonlinearly interacting spatially dependent oscillations are favored. We also demonstrate how the degree of phase coherence in light curve fluctuations influences the application of causality bounds on internal length scales. Subject headings: galaxies: active - X-rays: galaxies
Retrieve 5 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home