51 citations · 234 across the 23 of their papers we have counts for
23 papers
Extraction method for response functions from X-ray light curves of AGN by optimization algorithm
Sanhanat Deesamutara, Tirawut Worrakitpoonpon, Poemwai Chainakun +4
We introduce a numerical optimization method to extract the X-ray reverberation response functions from the multi-band light curves of the active galactic nuclei. This approach doe…
Radial Velocity Evidence for a Post-Mass-Transfer Massive Binary System NaSt1
Kittipong Wangnok, Samaporn Tinyanont, Ryan M. Lau +11
We present multi-epoch high-resolution optical spectroscopy () of the emission-line object NaSt1 to test its proposed binary nature, along with long-term multiba…
Hybrid corona and transient soft X-ray lags in Fairall 9
K. Khanthasombat, P. Chainakun, W. Luangtip +2
Fairall 9 is among the most massive Seyfert galaxies exhibiting a strong soft X-ray excess, but it is challenging to probe soft X-ray reverberation lags (if any) due to the long in…
Revealing Hidden Repeaters in the CHIME/FRB Catalog: Semi-Supervised Insights into the Fast Radio Burst Population
N. Mankatwit, P. Thongkonsing, S. Loekkesee +3
Fast radio bursts (FRBs) are millisecond-duration extragalactic transients, observationally classified as repeaters or nonrepeaters. This classification may be biased, as some appa…
The brightest X-ray AGNs at redshift
Cameron Heather, Teeraparb Chantavat, Siri Chongchitnan +1
Given recent X-ray observations of high-redshift active galactic nuclei (AGNs), we consider whether the extreme luminosities of these AGNs are consistent with current semi-analytic…
Extracting the X-ray reverberation response functions from the AGN light curves using an autoencoder
Sanhanat Deesamutara, Poemwai Chainakun, Tirawut Worrakitpoonpon +5
We study the X-ray reverberation in active galactic nuclei (AGN) using the variational autoencoder (VAE), which is a machine-learning algorithm widely used for signal processing an…
Tracing the evolving X-ray reverberation lags within an individual AGN light curve
N. Nakhonthong, P. Chainakun, W. Luangtip +1
We present the Granger causality (GC) test for the X-ray reverberation analysis of Active Galactic Nuclei (AGN). If the light curves in the continuum-dominated band help predict (G…
Parameter dependency on the public X-ray reverberation models kynxilrev and kynrefrev
K. Khanthasombat, P. Chainakun, A. J. Young
We present a comparative study of the constrained parameters of active galactic nuclei (AGN) made by the public X-ray reverberation model kynxilrev and kynrefrev that make use of t…
Investigating scaling relations in X-ray reverberating AGN using symbolic regression
P. Thongkonsing, P. Chainakun, T. Worrakitpoonpon +1
Symbolic regression (SR) is a regression analysis based on genetic algorithms to search for mathematical expressions that best fit a given data set, by allowing the expressions the…
Coronal height constraint in IRAS 13224-3809 and 1H 0707-495 by the random forest regressor
N. Mankatwit, P. Chainakun, W. Luangtip +1
We develop a random forest regressor (RFR) machine learning model to trace the coronal evolution in two highly variable active galactic nuclei (AGNs) IRAS 13224-3809 and 1H 0707-49…
Revealing the intrinsic X-ray reverberation lags in IRAS 13224-3809 through the Granger causality test
P. Chainakun, N. Nakhonthong, W. Luangtip +1
The Granger causality is an econometric test for determining whether one time series is useful for forecasting another one with a certain Granger lag. Here, the light curves in the…
Extended Corona Models of X-ray Reverberation in the AGN 1H~0707-495 and IRAS 13224-3809
S. Hancock, A. J. Young, P. Chainakun
We fit a new vertically extended corona model to previously measured reverberation time lags observed by \emph{XMM-Newton} in two extremely variable Narrow Line Seyfert 1 Active Ga…
Mapping the X-ray corona evolution of IRAS 13224-3809 with the power spectral density
Poemwai Chainakun, Wasuthep Luangtip, Jiachen Jiang +1
We develop the power spectral density (PSD) model to explain the nature of the X-ray variability in IRAS 13224-3809, including the full effects of the X-ray reverberation due to th…
Predicting the black hole mass and correlations in X-ray reverberating AGN using neural networks
P. Chainakun, I. Fongkaew, S. Hancock +1
We develop neural network models to predict the black hole mass using 22 reverberating AGN samples in the XMM-Newton archive. The model features include the fractional excess varia…
Effects of the refractive index of the X-ray corona on the emission lines in AGN
P. Chainakun, A. Watcharangkool, A. J. Young
X-ray reflection from an accretion disc produces characteristic emission lines allowing us to probe the innermost regions in AGN. We investigate these emission lines under a framew…
X-ray reverberation models of the disc wind in ultraluminous X-ray source NGC 5408 X-1
W. Luangtip, P. Chainakun, S. Loekkesee +3
Majority of ultraluminous X-ray sources (ULXs) are believed to be super-Eddington objects, providing a nearby prototype for studying an accretion in super-critical regime. In this…
The nature of the extreme X-ray variability in the NLS1 1H 0707-495
M. L. Parker, W. N. Alston, L. Härer +11
We examine archival XMM-Newton data on the extremely variable narrow-line Seyfert 1 (NLS1) active galactic nucleus (AGN) 1H 0707-495. We construct fractional excess variance (Fvar)…
Machine learning application to detect light echoes around black holes
P. Chainakun, N. Mankatwit, P. Thongkonsing +1
X-ray reverberation has become a powerful tool to probe the disc-corona geometry near black holes. Here, we develop Machine Learning (ML) models to extract the X-ray reverberation…
Evolution of the truncated disc and inner hot-flow of GX 339-4
P. Chainakun, W. Luangtip, A. J. Young +2
Aims. We study the changes in geometry of the truncated disc and the inner hot-flow of GX 339-4 by analyzing the Power SpectralDensity (PSD) extracted from six XMM-Newton observati…
Modelling the X-ray power spectra of AGN by using reprocessing echoes from an extended corona
Poemwai Chainakun
Characteristic signatures that X-ray reverberation from an extended corona can manifest in the observed PSD of AGN are investigated. The presence of two X-ray blobs illuminating an…
X-ray time lags in AGN: inverse-Compton scattering and spherical corona model
P. Chainakun, A. Watcharangkool, A. J. Young +1
We develop a physically motivated, spherical corona model to investigate the frequency-dependent time lags in AGN. The model includes the effects of Compton up-scattering between t…
Relativistic X-ray reverberation modelling of the combined time-averaged and lag-energy spectra in AGN
P. Chainakun, A. J. Young, E. Kara
General relativistic ray tracing simulations of the time-averaged spectrum and energy-dependent time delays in AGN are presented. We model the lamp-post geometry in which the accre…
Simultaneous spectral and reverberation modelling of relativistic reflection in Mrk 335
P. Chainakun, A. J. Young
We present an X-ray spectral and timing model to investigate the broad and variable iron line seen in the high flux state of Mrk 335. The model consists of a variable X-ray source…