Document Type
Article
Abstract
Timing techniques are powerful tools to study dynamical astrophysical phenomena. In the X-ray band, they offer the potential of probing accretion physics down to the event horizon. Recent work has used frequency- and energy-dependent time lags as tools for studying relativistic reverberation around the black holes in several Seyfert galaxies. This was achieved due to the evenly sampled light curves obtained using XMM-Newton. Continuously sampled data are, however, not always available and standard Fourier techniques are not applicable. Here, building on the work of Miller et al., we discuss and use a maximum likelihood method to obtain frequency-dependent lags that takes into account light curve gaps. Instead of calculating the lag directly, the method estimates the most likely lag values at a particular frequency given two observed light curves. We use Monte Carlo simulations to assess the method's applicability and use it to obtain lag-energy spectra from Suzaku data for two objects, NGC 4151 and MCG-5-23-16, that had previously shown signatures of iron K reverberation. The lags obtained are consistent with those calculated using standard methods using XMM-Newton data.
Disciplines
Cosmology, Relativity, and Gravity | External Galaxies | Instrumentation
Recommended Citation
Calculating Time Lags from Unevenly Sampled Light Curves
A. Zoghbi et al. 2013 ApJ 777 24
Included in
Cosmology, Relativity, and Gravity Commons, External Galaxies Commons, Instrumentation Commons
Comments
NOTICE IN COMPLIANCE WITH PUBLISHER POLICY: ©2013, American Astronomical Society. Available at: doi:10.1088/0004-637X/777/1/24