Related papers: An X-ray high-frequency quasi-periodic oscillation…
Quasi-periodic oscillations (QPOs) are coherent peaks of variability power observed in the X-ray power spectra (PSDs) of stellar mass X-ray binaries (XRBs). A scale invariance of the accretion process implies they should be present in the…
This study aims to detect and characterize quasi-periodic oscillations (QPOs) signals in X-ray observations of NGC 4151. We employed the Weighted Wavelet Z-transform (WWZ) and Lomb-Scargle periodogram (LSP) methods for our analysis. QPO…
Quasi-periodic oscillation (QPO) detected in the X-ray radiation of black hole X-ray binaries (BHXBs) is thought to originate from dynamical processes in the close vicinity of the black holes (BHs), and thus carries important physical…
In the narrow-line Seyfert 1 galaxy Mrk 766, a Quasi-Periodic Oscillation (QPO) signal with a period of $\sim6450$ s is detected in the \emph{XMM-Newton} data collected on 2005 May 31. This QPO signal is highly statistical significant at…
In the narrow-line Seyfert 1 galaxy 1H 0707-495, recently a transient quasi-periodic oscillation (QPO) signal with a frequency of $\sim 2.6\times 10^{-4}$ Hz has been detected at a high statistical significance. Here, we reanalyze the same…
Following our previous work of Lachowicz & Czerny (2005), we explore further the application of the continuous wavelet transform to X-ray astronomical signals. Using the public archive of the XMM-Newton satellite, we analyze all available…
We report the discovery of a $\sim 1.5 \times 10^{-4}$ Hz ($\sim 2$ hr) X-ray quasi-periodic oscillation (QPO) in the active galaxy MS 2254.9-3712, using a $\sim 70$ ks XMM-Newton observation. The QPO is significantly detected ($\sim 3.3…
Here we report an optical quasi-periodic oscillation (QPO) with a period of $\sim$134~day detected in g- and r-band light curves of a narrow-line Seyfert 1 galaxy TXS 1206+549 at redshift of 1.34 with the data from the Zwicky Transient…
We found a possible ~ 1 hour quasi-periodic oscillation (QPO) in a ~ 55 ks X-ray observation of the narrow-line Seyfert 1 galaxy MCG--06--30--15 made with the XMM-Newton EPIC/pn detector in the energy range 0.3 -- 10 keV. We identify a…
We apply the global mode analysis, which has been recently developed for the modeling of kHz quasi-periodic oscillations (QPOs) from neutron stars, to the inner region of an accretion disk around a rotating black hole. Within a…
Following the discovery of 3:2 resonance quasi-periodic oscillations (QPOs) in M82X-1 (Pasham et al. 2014), we have constructed power density spectra (PDS) of all 15 (sufficiently long) {\it XMM-Newton} observations of the ultraluminous…
We report the discovery with XMM-Newton of an approximately 7 mHz X-ray (0.3-10.0 keV) quasi-periodic oscillation (QPO) from the eclipsing, high-inclination black hole binary IC 10 X-1. The QPO is significant at > 4.33 sigma confidence…
The X-ray quasi-periodic oscillation (QPO) at $\sim 2.6 \times 10^{-4}$ Hz in RE J1034+396 has been robustly observed in the 0.2-10 keV band of one $\sim 90$ ks XMM-Newton observation, but was not detected in subsequent observations. Here,…
Quasi-periodic oscillations (QPOs) at frequencies near 1000 Hz were recently discovered in several x-ray binaries containing neutron stars. Two sources show no correlation between QPO frequency and source count rate (Berger et al. 1996,…
RE J1034+396 is a narrow-line Seyfert 1 galaxy (NLS1) in which the first significant X-ray quasi-periodic oscillation (QPO) in an active galactic nuclei (AGN) was observed in 2007. We report the detection of this QPO in a recent XMM-Newton…
Quasi-periodic oscillations (QPOs) have been widely observed in black hole X-ray binaries (BHBs), which often exhibit significant X-ray variations. Extensive research has explored the long-term evolution of the properties of QPOs in BHBs.…
We report evidence for a quasi-periodic oscillation (QPO) in the optical light curve of KIC 9650712, a narrow-line Seyfert 1 galaxy in the original Kepler field. After the development and application of a pipeline for Kepler data specific…
The Seyfert 1 galaxy J1626+5120 is estimated to host a $10^8 M_{\odot}$ black hole (BH) accreting at Eddington ratio $\dot{m}_{\text{Edd}} \approx 0.043$. Its long-term multi-band light curve data show flicker-like variations, but in a…
We have carried out a systematic study of the properties of the kilo-Hertz quasi-periodic oscillations (QPO) observed in the X-ray emission of the neutron star low-mass X-ray binary 4U1608-52, using archival data obtained with the Rossi…
We report the detection of high frequency variability in the black hole X-ray transient XTE J1650-500. A quasi-periodic oscillation (QPO) was found at 250 Hz during a transition from the hard to the soft state. We also detected less…