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Testing for X-ray Periodicities in Seyfert GalaxiesThe Deep Survey instrument on the Extreme Ultraviolet Explorer obtained long, continuous light-curves of 10 Seyfert galaxies with durations of 5-33 days each. We present a uniform reduction of these data, which account for a total of 209 days of observation. Several of the light curves are uniquely suited to a search for periodicity or QPOs in the range of hours to days that might be expected from dynamical effects in the inner accretion disks around approximately 10(exp 8) solar mass black holes. Power spectra show features in three of the longest observations that could be transient periods: 0.9 days in RX J0437.4-4711, 2.1 days in Ton S180, and 5.8 days in 1H 0419-577. These period values seem to be unrelated to the length of the observations, which are similar in the three cases, but they do roughly scale as the luminosity of the objects, which would be expected in a dynamical scenario if the black hole masses also scale with luminosity. The significance of these periods will be evaluated in a future publication by using the method of Timmer & Konig (1995), which properly takes into account the red-noise properties of AGN light curves.
Document ID
20020058226
Acquisition Source
Goddard Space Flight Center
Document Type
Contractor or Grantee Report
Authors
Halpern, Jules P. (Columbia Univ. New York, NY United States)
Oliversen, Ronald J.
Date Acquired
September 7, 2013
Publication Date
June 1, 2002
Subject Category
Astrophysics
Report/Patent Number
CAL-3463
Funding Number(s)
CONTRACT_GRANT: NAG5-9094
CONTRACT_GRANT: NAG5-26555
CONTRACT_GRANT: NAG5-7584
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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