Using simultaneous modeling of continuum lag-spectrum and broadband SED of Fairall 9 with the H0RIZON-AGN model, the authors obtain H0 = 72.4_{-3.7}^{+3.4} km s^{-1} Mpc^{-1}.
On Uncertainties in Cross-Correlation Lags and the Reality of Wavelength-Dependent Continuum Lags in Active Galactic Nuclei
4 Pith papers cite this work. Polarity classification is still indexing.
4
Pith papers citing it
abstract
We describe a model-independent method of assessing the uncertainties in cross-correlation lags determined from AGN light curves, and use this method to investigate the reality of lags between UV and optical continuum variations in well-studied AGNs. Our results confirm the existence of such lags in NGC 7469. We find that the continuum variations at 1825 A, 4845 A, and 6962 A follow those at 1315A by 0.22^{+0.12}_{-0.13} days, 1.25^{+0.48}_{-0.35} days, and 1.84^{+0.93}_{-0.94} days, respectively, based on the centroids of the cross-correlation functions; the error intervals quoted correspond to 68% confidence levels, and each of these lags is greater than zero at no less than 97% confidence. We do not find statistically significant interband continuum lags in NGC 5548, NGC 3783, or Fairall 9. Wavelength-dependent continuum lags may be marginally detected in the case of NGC 4151. However, on the basis of theoretical considerations, wavelength-dependent continuum lags in sources other than NGC 7469 are not expected to have been detectable in previous experiments. We also confirm the existence of a statistically significant lag between X-ray and UV continuum variations in the blazar PKS 2155-304.
years
2026 4verdicts
UNVERDICTED 4representative citing papers
Variable column density and covering factor of three ionized absorbers in clumpy disk winds explain the X-ray variability in I Zw 1 with stable corona.
Simultaneous observations of NGC 4151 and UGC 3374 show that ICCF-Cut photometric Hα light curves and lags match spectroscopic results within uncertainties, with minor discrepancies attributed to He I contamination that can be corrected.
Radio precedes X-ray Compton luminosity by ~3 days in the rising hard state but lags by ~8 days in the decaying hard state of GX 339-4, with inner magnetic field strength estimated from accretion rate and truncation radius accounting for both.
citing papers explorer
-
HALO II: Constraining Hubble constant $H_{0}$ through continuum delay fitting of Fairall 9
Using simultaneous modeling of continuum lag-spectrum and broadband SED of Fairall 9 with the H0RIZON-AGN model, the authors obtain H0 = 72.4_{-3.7}^{+3.4} km s^{-1} Mpc^{-1}.
-
Strong X-ray Variability of I Zwicky 1: Obscuration from Clumpy Accretion-Disk Winds
Variable column density and covering factor of three ionized absorbers in clumpy disk winds explain the X-ray variability in I Zw 1 with stable corona.
-
Validating the ICCF-Cut Method with Simultaneous Photometric and Spectroscopic H$\alpha$ Reverberation Mapping of NGC 4151 and UGC 3374
Simultaneous observations of NGC 4151 and UGC 3374 show that ICCF-Cut photometric Hα light curves and lags match spectroscopic results within uncertainties, with minor discrepancies attributed to He I contamination that can be corrected.
-
Radio-X-ray Time Lags in GX 339-4: Probing Magnetic Field Transport in Black Hole Accretion
Radio precedes X-ray Compton luminosity by ~3 days in the rising hard state but lags by ~8 days in the decaying hard state of GX 339-4, with inner magnetic field strength estimated from accretion rate and truncation radius accounting for both.