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Related papers: Examining AGN UV/optical Variability Beyond the Si…

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Despite intensive studies of kink oscillations of coronal loops in the last decade, a large scale statistically significant investigation of the oscillation parameters has not been made using data from the Solar Dynamics Observatory (SDO).…

Solar and Stellar Astrophysics · Physics 2016-01-13 C. R. Goddard , G. Nistic`o , V. M. Nakariakov , I. V. Zimovets

The system of oscillator interacting with vacuum is considered as a problem of random motion of quantum reactive harmonic oscillator (QRHO). It is formulated in terms of a wave functional regarded as complex probability process in the…

Quantum Physics · Physics 2007-05-23 Alexander V. Bogdanov , Ashot S. Gevorkyan

The harmonic oscillator is the paragon of physical models; conceptually and computationally simple, yet rich enough to teach us about physics on scales that span classical mechanics to quantum field theory. This multifaceted nature extends…

High Energy Physics - Theory · Physics 2021-02-10 Arpan Bhattacharyya , Wissam Chemissany , S. Shajidul Haque , Jeff Murugan , Bin Yan

We consider the Fermi quantization of the classical damped harmonic oscillator (dho). In past work on the subject, authors double the phase space of the dho in order to close the system at each moment in time. For an infinite-dimensional…

Quantum Physics · Physics 2009-11-10 D. C. Latimer

We develop a model of an accretion disc in which the variability induced at a given radius is governed by a damped harmonic oscillator at the corresponding epicyclic frequency. That variability induces both linear and non-linear responses…

Astrophysics · Physics 2009-11-13 R. Misra , A. A. Zdziarski

The relation between X-ray and UV/optical variability in AGNs has been explored in many individual sources, however a large sample study is yet absent. Through matching the XMM-Newton serendipitous X-ray and UV source catalogs with SDSS…

Astrophysics of Galaxies · Physics 2022-04-20 Hao Sou , Jun-Xian Wang , Zhang-Liang Xie , Wen-Yong Kang , Zhen-Yi Cai

Horizontal line arrays are often employed in underwater environments to estimate the direction of arrival (DOA) of a weak signal. Conventional beamforming (CB) is robust but has wide beamwidths and high-level sidelobes. High-resolution…

Signal Processing · Electrical Eng. & Systems 2020-12-09 Qi Zhang , Jiang Zhu , Yuantao Gu , Zhiwei Xu

A long-term variability study spanning a range of black hole mass systems, from microquasars hosting stellar-mass black holes to active galactic nuclei (AGNs) harboring supermassive black holes, provides new insights into the physics of…

High Energy Astrophysical Phenomena · Physics 2026-04-20 Yongyun Chen , Qiusheng Gu , Junhui Fan , Dingrong Xiong , Xiaoling Yu , Xiaogu Zhong , Xiaotong Guo

We present the first short time-scale ($\sim$hours to days) optical variability study of a large sample of Active Galactic Nuclei (AGN) observed with the Kepler/K2 mission. The sample contains 252 AGN observed over four campaigns with $\sim…

High Energy Astrophysical Phenomena · Physics 2018-03-14 E. Aranzana , E. Kording , P. Uttley , S. Scaringi , S. Bloemen

Optical quasi-periodic oscillations (QPOs) with periodicity around hundreds to thousands of days have been accepted as an efficient indicator for sub-pc binary black hole systems (BBHs) in broad line active galactic nuclei (BLAGN). However,…

Astrophysics of Galaxies · Physics 2025-10-17 Zhang XueGuang

We present the first direct measurement of the mean Halo Occupation Distribution (HOD) of X-ray selected AGN in the COSMOS field at z < 1, based on the association of 41 XMM and 17 C-COSMOS AGN with member galaxies of 189 X-ray detected…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 V. Allevato , A. Finoguenov , G. Hasinger , T. Miyaji , N. Cappelluti , M. Salvato , G. Zamorani , R. Gilli , M. R. George , M. Tanaka , M. Brusa , J. Silverman , F. Civano , M. Elvis , F. Shankar

The origin of the optical flux variability in active galactic nuclei (AGN) is largely unknown. Previous studies have correlated features of the variability structure function (SF) with AGN properties, though they mostly involved…

Astrophysics of Galaxies · Physics 2026-05-06 Ashley Hai Tung Tan , Christian Wolf , Neelesh Amrutha , Christopher A. Onken , John L. Tonry , Rachel Webster

Supermassive black hole binaries (SMBHB) are expected to produce periodic modulations in active galactic nuclei (AGN) light curves, but distinguishing such signals from stochastic red-noise variability remains a major challenge. We present…

High Energy Astrophysical Phenomena · Physics 2026-05-13 Pablo Huijse , Jordy Davelaar , Joris De Ridder , Nicholas Jannsen , Conny Aerts

We compile and analyse long term (~10 year) submillimetre (1.3, 0.87, 0.43 mm, submm) wavelength light curves of the Galactic centre black hole, Sagittarius A*. The 0.87 and 0.43 mm data are taken from the literature, while the majority of…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Jason Dexter , Brandon Kelly , Geoffrey C. Bower , Daniel P. Marrone , Jordan Stone , Richard Plambeck , Sheperd S. Doeleman

We conduct an analysis of over 60,000 dwarf galaxies (7<=log(M_*/M_\odot)<=10) in search of photometric variability indicative of active galactic nuclei (AGNs). Using data from the Young Supernova Experiment (YSE), a time domain survey on…

The quantum harmonic oscillator (QHO), one of the most important and ubiquitous model systems in quantum mechanics, features equally spaced energy levels or eigenstates. Here we present a new class of nearly ideal QHOs formed by hydrogenic…

Quantum Physics · Physics 2022-11-15 Guangqiang Mei , Pengfei Suo , Li Mao , Min Feng , Limin Cao

On the basis of data from an energy-conserving 3D general relativistic MHD simulation, we predict the statistical character of variability in the coronal luminosity from accreting black holes. When the inner boundary of the corona is…

High Energy Astrophysical Phenomena · Physics 2009-09-28 Scott C. Noble , Julian H. Krolik

We numerically examine centrifugally supported shock waves in 2D rotating accretion flows around a stellar-mass (10M_sun) and a supermassive (10^6M_sun) black holes over a wide range of input accretion rates of 10^7 >\dot M/\dot…

Astrophysics · Physics 2008-11-26 T. Okuda , V. Teresi , D. Molteni

This paper is devoted to the study of the asymptotic dynamics of a class of coupled second order oscillators driven by white noises. It is shown that any system of such coupled oscillators with positive damping and coupling coefficients…

Dynamical Systems · Mathematics 2013-11-08 Wenxian Shen , Zhongwei Shen , Shengfan Zhou

This is the fifth paper in a series of investigations of the clustering properties of luminous, broad-emission-line active galactic nuclei (AGN) identified in the ROSAT All-Sky Survey (RASS) and Sloan Digital Sky Survey (SDSS). In this work…