Direct Measurement of the X-Ray Time-delay Transfer Function in Active Galactic Nuclei

  title={Direct Measurement of the X-Ray Time-delay Transfer Function in Active Galactic Nuclei},
  author={E. Legg and Lance L. Miller and T. J. Turner and Margherita Giustini and J. N. Reeves and S. B. Kraemer},
  journal={The Astrophysical Journal},
The origin of the observed time lags, in nearby active galactic nuclei (AGNs), between hard and soft X-ray photons is investigated using new XMM-Newton data for the narrow-line Seyfert I galaxy Ark 564 and existing data for 1H 0707-495 and NGC 4051. These AGNs have highly variable X-ray light curves that contain frequent, high peaks of emission. The averaged light curve of the peaks is directly measured from the time series, and it is shown that (1) peaks occur at the same time, within the… 
Hard X-Ray Lags in Active Galactic Nuclei: Testing the Distant Reverberation Hypothesis with NGC 6814
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General relativistic modelling of the negative reverberation X-ray time delays in AGN
We present the first systematic physical modelling of the time-lag spectra between the soft (0.3–1 keV) and the hard (1.5–4 keV) X-ray energy bands, as a function of Fourier frequency, in a sample of
UV and X-Ray Variability of the Narrow-Line Seyfert 1 Galaxy Ark 564
We analyse eight XMM-Newton observations of the bright Narrow-Line Seyfert 1 galaxy Arakelian 564 (Ark 564). These observations, separated by ~6 days, allow us to look for correlations between the
X-ray time delays from the Seyfert 2 galaxy IRAS 18325−5926
Using new XMM-Newtonobservations we detect hard X-ray time lags in the rapid variability of the Compton-thin Seyfert 2 galaxy IRAS 18325 5926. The higher-energy X-ray variations lag behind correlated
The flux-dependent X-ray time lags in NGC 4051
We present an analysis of the X-ray time lags for the highly variable Seyfert 1 galaxy NGC 4051, based on a series of XMM-Newton observations taken in 2009. We investigate the Fourier frequency
Modelling the broad Fe Kα reverberation in the AGN NGC 4151
The recent detection of X-ray reverberation lags, especially in the Fe Kα line region, around active galactic nuclei (AGN) has opened up the possibility of studying the time-resolved response
Revealing a hard X-ray spectral component that reverberates within one light hour of the central supermassive black hole in Ark 564
Ark 564 (z=0.0247) is an X-ray-bright NLS1. By using advanced X-ray timing techniques, an excess of "delayed" emission in the hard X-ray band (4-7.5 keV) following about 1000 seconds after "flaring"
Several X-ray observations have recently revealed the presence of reverberation time delays between spectral components in active galactic nuclei. Most of the observed lags are between the power-law
X-ray reverberation lags of the Fe–K line due to AGN disc winds
Short X-ray reverberation lags are seen across a broad Fe–K energy band in more than 20 active galactic nuclei (AGNs). This broad iron line feature in the lag spectrum is most significant in
Modelling the extreme X-ray spectrum of IRAS 13224−3809
The extreme narrow-line Seyfert 1 galaxy IRAS 13224−3809 shows significant variability, frequency-dependent time lags, and strong Fe K line and Fe L features in the long 2011 XMM–Newton observation.


Non‐linear X‐ray variability in X‐ray binaries and active galaxies
We show that the rms-flux relation recently discovered in the X-ray light curves of Active Galactic Nuclei (AGN) and X-ray binaries (XRBs) implies that the light curves have a formally non-linear,
Discovery of multiple Lorentzian components in the X-ray timing properties of the Narrow Line Seyfert 1 Ark 564
We present a power spectral analysis of a 100-ks XMM-Newton observation of the Narrow Line Seyfert 1 galaxy Ark 564. When combined with earlier RXTE and ASCA observations, these data produce a power
Combined long and short time-scale X-ray variability of NGC 4051 with RXTE and XMM-Newton
We present a comprehensive examination of the X-ray variability of the narrow-line Seyfert 1 (NLS 1) galaxy NGC 405 1, one of the most variable active galactic nuclei (AGN) in the sky. We combine
Spectral variability and reverberation time delays in the Suzaku X‐ray spectrum of NGC 4051
Long-exposure Suzaku X-ray observations of the nearby active galaxy NGC 4051 from 2005 and 2008 are analysed, in an attempt to reach a self-consistent understanding of both the spectral variability
X-ray Characteristics of NGC 3516: A View through the Complex Absorber
We consider new Suzaku data for NGC 3516 taken during 2009, along with other recent X-ray observations of the source. The cumulative characteristics of NGC 3516 cannot be explained without invoking
Variable iron-line emission near the black hole of Markarian 766
Aims. We investigate the link between ionised Fe X-ray line emission and continuum emission in a bright nearby AGN, Mrk 766. Methods. A new long (433 ks) XMM-Newton observation is analysed, together
Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
Correlated variations in the line and continuum emission from active galactic nuclei (AGNs) can be used to determine the size and geometry of the broad emission-line regions (BLRs). We have spectro-
Relative Timing and Spectra of Solar Flare Hard X-ray Sources
Hard X-ray lightcurves, spectrograms, images, and spectra of three medium-sized flares observed by the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) are presented. Imaging
Broad iron L line and X-ray reverberation in 1H0707-495
A detailed analysis of a long XMM-Newton observation of the narrow-line type 1 Seyfert galaxy 1H0707-495 is presented, including spectral fitting, spectral variability and timing studies. The two
Spectral-timing evidence for a very high state in the narrow-line Seyfert 1 Ark 564
We use a 100 ks long XMM-Newton observation of the narrow-line Seyfert 1 galaxy Ark 564 and combine it with the month-long monitoring of the same source produced by ASCA, to calculate the phase lags