相关论文: Frequency-resolved lags in UV/optical continuum re…

The X-ray emission from accreting black hole (BH) systems displays strong variability. Short reverberation lags are expected between the primary hard X-ray continuum and the reprocessed disc emission. These lags depend on light-travel…

Five archived X-ray observations of NGC 4051, taken using the NuSTAR observatory, have been analysed, revealing lags between flux variations in bands covering a wide range of X-ray photon energy. In all pairs of bands compared, the harder…

We report the first study of Fourier-frequency-dependent coherence and phase/time lags at optical wavelengths of cataclysmic variables (MV Lyr and LU Cam) displaying typical flickering variability in white light. Observations were performed…

To understand the physical processes governing accretion discs we can study active galactic nuclei (AGN), X-ray binary systems (XRBs) and cataclysmic variables (CVs). It has been shown that XRBs and CVs show similar observational properties…

We present 1.8 years of near-daily Swift monitoring of the bright, strongly variable Type 1 AGN Fairall 9. Totaling 575 successful visits, this is the largest such campaign reported to date. Variations within the UV/optical are…

We test the "reprocessing paradigm" of the optical -- UV AGN variability by detailed modeling of the correlated X-ray -- optical (3590 and 5510 Angstrem) variability of the recent multiwavelength campaign of NGC 3516. We produce model…

We here estimate the mass M of the central object in five active galactic nuclei (AGNs), using the most recent reverberation data obtained by the AGN Watch Consortium. The cross-correlation function (CCF) centroids of the broad Ly-alpha…

The variable continuum emission of an active galactic nucleus (AGN) produces corresponding responses in the broad emission lines, which are modulated by light travel delays, and contain information on the physical properties, structure, and…

Measurements of the physical properties of accretion disks in active galactic nuclei are important for better understanding the growth and evolution of supermassive black holes. We present the accretion disk sizes of 22 quasars from…

The recent detection of X-ray reverberation lags, especially in the Fe K\alpha\ line region, around Active Galactic Nuclei (AGN) has opened up the possibility of studying the time-resolved response (reflection) of hard X-rays from the…

We present a reverberation mapping (RM) experiment that combines broad- and intermediate-band photometry; it is the first such attempt targeting a sample of 13 quasars at $0.2<z<0.9$. The quasars were selected to have strong H$\alpha$ or…

We present optical broadband (B and R) observations of the Seyfert 1 nucleus NGC 3516, obtained at Wise Observatory from 1997 March to 1998 September, contemporaneously with the X-ray 2-10 keV measurements of RXTE. The cross correlation…

The origin of short timescale (weeks/months) variability of AGN, whether due to intrinsic disc variations or reprocessing of X-ray emission by a surrounding accretion disc, has been a puzzle for many years. However recently a number of…

Photometric reverberation mapping employs a wide bandpass to measure the AGN continuum variations and a suitable band, usually a narrow band (NB), to trace the echo of an emission line in the broad line region (BLR). The narrow band catches…

We present a 140ks observation of NGC 4593 with XMM-Newton providing simultaneous and continuous PN X-ray and OM UV (UVW1 2910\AA) lightcurves which sample short-timescale variations better than previous observations. These observations…

Understanding the geometry and kinematics of the broad line region (BLR) of active galactic nuclei (AGN) is important to estimate black hole masses in AGN and study the accretion process. The technique of reverberation mapping (RM) has…

We present composite broad-line region (BLR) reverberation-mapping lag measurements for \halpha, \hbeta, \HeII\,$\lambda4686$ and \MgII\ for a sample of 144, $z\lesssim 1$ quasars from the Sloan Digital Sky Survey Reverberation Mapping…

Reverberation mapping of nearby active galactic nuclei has led to estimates of broad-line-region (BLR) sizes and central-object masses for some 37 objects to date. However, successful reverberation mapping has yet to be performed for…

Thermal reverberation in accretion discs of active galactic nuclei is thought to be the reason of the continuum UV/optical time lags seen in these sources. Recently, we studied thermal reverberation of a standard Novikov-Thorne accretion…

The dynamical and geometric structures of the Broad Line Region (BLR), along with the origins of continuum time delays in active galaxies, remain topics of ongoing debate. In this study, we aim to reproduce the observed broadband spectrum,…