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The X-ray variability of NGC 6814 - Power spectrumThe existence of the periodic component seen in NGC 6814 with Exosat at 12,000 +/- 100 s is confirmed by a power spectrum and folded light curve analysis of unevenly sampled Ginga data. A comparison of the power spectra produced from simulated light curves with that observed enables the intrinsic shape of the power spectrum of the source to be determined despite the distortions introduced by the window function. The best estimate for the period is 12,132 +/- 3 s, where the error is that derived from simulations. An upper limit to the rate of change of period of about 10 exp -9 is inferred if the light curves are truly phase-coherent, but as this is not required by the data, the conservative upper limit is not greater than 5 x 10 exp -7. The large amount of power in the periodic component and its stability both suggest occultation of the source as its origin.
Document ID
19930032115
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Done, C.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Madejski, G. M.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Mushotzky, R. F.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Turner, T. J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Koyama, K.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Kunieda, H.
(Nagoya Univ. Japan)
Date Acquired
August 15, 2013
Publication Date
November 20, 1992
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 400
Issue: 1
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
93A16112
Distribution Limits
Public
Copyright
Other

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