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Related papers: Extracting the X-ray reverberation response functi…

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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…

High Energy Astrophysical Phenomena · Physics 2019-05-15 B. De Marco , G. Ponti

X-ray variability provides a powerful probe of the innermost regions of active galactic nuclei (AGNs), offering valuable insights into the accretion process and the structure of the corona. Previous studies have established a correlation…

High Energy Astrophysical Phenomena · Physics 2026-04-07 Ruisong Xia , Hao Liu , Yongquan Xue , Jialai Wang , Guowei Ren , Mouyuan Sun , Shifu Zhu , Mengqiu Huang , Qingwen Wu , Xian-Liang Lu , Zhen-Bo Su , Shuying Zhou

The bulk of the X-ray emission in Active Galactic Nuclei (AGN) is produced very close to the accreting supermassive black hole (SMBH), in a corona of hot electrons which up scatters optical and ultraviolet photons from the accretion flow.…

High Energy Astrophysical Phenomena · Physics 2018-09-19 C. Ricci , L. C. Ho , A. C. Fabian , B. Trakhtenbrot , M. J. Koss , Y. Ueda , A. Lohfink , T. Shimizu , F. E. Bauer , R. Mushotzky , K. Schawinski , S. Paltani , I. Lamperti , E. Treister , K. Oh

Determining the physical parameters of pulsating variable stars such as RR Lyrae is essential for understanding their internal structure, pulsation mechanisms, and evolutionary state. In this study, we present a machine learning framework…

Solar and Stellar Astrophysics · Physics 2025-07-08 Nitesh Kumar , Harinder P. Singh , Oleg Malkov , Santosh Joshi , Kefeng Tan , Philippe Prugniel , Anupam Bhardwaj

X-ray polarimetry can potentially constrain the unknown geometrical shape of AGN coronae. We present simulations of the X-ray polarization signal expected from AGN coronae, assuming three different geometries, namely slab, spherical and…

High Energy Astrophysical Phenomena · Physics 2022-01-05 F. Ursini , G. Matt , S. Bianchi , A. Marinucci , M. Dovčiak , W. Zhang

In this study, we present novel calculations of X-ray polarization from radio-quiet and unobscured active galactic nuclei (AGNs) using the Monte Carlo code MONK, which includes all general and special relativity effects. Our geometric…

High Energy Astrophysical Phenomena · Physics 2025-09-01 D. Tagliacozzo , S. Bianchi. V. Gianolli , A. Gnarini , A. Marinucci , G. Matt , F. Ursini , W. Zhang

We present a new technique to generate the light curves of RRab stars in different photometric bands ($I$ and $V$ bands) using Artificial Neural Networks (ANN). A pre-computed grid of models was used to train the ANN, and the architecture…

Solar and Stellar Astrophysics · Physics 2023-04-03 Nitesh Kumar , Anupam Bhardwaj , Harinder P. Singh , Susmita Das , Marcella Marconi , Shashi M. Kanbur , Philippe Prugniel

Distributed learning and Edge AI necessitate efficient data processing, low-latency communication, decentralized model training, and stringent data privacy to facilitate real-time intelligence on edge devices while reducing dependency on…

Machine Learning · Computer Science 2025-07-08 Lucas Heublein , Simon Kocher , Tobias Feigl , Alexander Rügamer , Christopher Mutschler , Felix Ott

To gain a better understanding of the inner disc region that comprises active galactic nuclei it is necessary to understand the pattern in which the disc is illuminated (the emissivity profile) by X-rays emitted from the continuum source…

High Energy Astrophysical Phenomena · Physics 2017-09-27 A. G. Gonzalez , D. R. Wilkins , L. C. Gallo

AIMS: We present an analysis of an XMM-Newton observation of the dwarf novae V1504 Cyg during the decline from an outburst. Our goal is to search for evidence for an evaporated X-ray corona. Such a corona can be understood as an optically…

Solar and Stellar Astrophysics · Physics 2023-06-28 A. Dobrotka , J. -U. Ness , A. A. Nucita , M. Melicherčík

Continuous speech representations based on Variational Autoencoders (VAEs) have emerged as a promising alternative to traditional spectrogram or discrete token based features for speech generation and reconstruction. Recent research has…

Sound · Computer Science 2026-05-26 Changhao Cheng , Wei Wang , Wangyou Zhang , Dongya Jia , Jian Wu , Zhuo Chen , Yanmin Qian

Variational Auto-encoders (VAEs) have been very successful as methods for forming compressed latent representations of complex, often high-dimensional, data. In this paper, we derive an alternative variational lower bound from the one…

Machine Learning · Computer Science 2019-03-20 Shuyu Lin , Ronald Clark , Robert Birke , Niki Trigoni , Stephen Roberts

This paper presents an in depth look at the jet and coronal properties of 41 AGN. Utilizing the highest quality NuSTAR, XMM-Newton, and NVSS 1.4 GHz data, we find that the radio Eddington luminosity inversely scales with X-ray reflection…

High Energy Astrophysical Phenomena · Physics 2017-02-08 Ashley L. King , Anne Lohfink , Erin Kara

Variational Auto-Encoder (VAE) has been widely applied as a fundamental generative model in machine learning. For complex samples like imagery objects or scenes, however, VAE suffers from the dimensional dilemma between reconstruction…

Machine Learning · Computer Science 2020-02-18 Deli Zhao , Jiapeng Zhu , Bo Zhang

The Active Galactic Nuclei (AGN) produce copious amounts of X-rays through the corona that is the hot gas that lies close to the accretion disk. The temperature of the corona can be accurately determined by the cut-off signature in the…

High Energy Astrophysical Phenomena · Physics 2021-12-01 A. Akylas , I. Georgantopoulos

We compute fully relativistic disc response functions in the case of the "lamp-post" geometry using the full observed reflection spectrum for various X-ray source heights, disc inclination, and spin values of the central black hole. Since…

High Energy Astrophysical Phenomena · Physics 2016-03-23 I. Papadakis , T. Pechacek , M. Dovciak , A. Epitropakis , D. Emmanoulopoulos , V. Karas

AGN exhibit complex hard X-ray spectra. Our current understanding is that the emission is dominated by inverse Compton processes which take place in the corona above the accretion disk, and that absorption and reflection in a distant…

High Energy Astrophysical Phenomena · Physics 2009-06-25 V. Beckmann , T. J. -L. Courvoisier , N. Gehrels , P. Lubinski , J. Malzac , P. O. Petrucci , C. R. Shrader , S. Soldi

The active galactic nuclei X-ray luminosity function traces actively accreting supermassive black holes and is essential for the study of the properties of the active galactic nuclei (AGN) population, black hole evolution, and galaxy-black…

Effective treatment for rectal cancer relies on accurate lymph node metastasis (LNM) staging. However, radiological criteria based on lymph node (LN) size, shape and texture morphology have limited diagnostic accuracy. In this work, we…

Computer Vision and Pattern Recognition · Computer Science 2025-07-17 Benjamin Keel , Aaron Quyn , David Jayne , Maryam Mohsin , Samuel D. Relton

Gaia Data Release 3 (DR3) published for the first time epoch photometry, BP/RP (XP) low-resolution mean spectra, and supervised classification results for millions of variable sources. This extensive dataset offers a unique opportunity to…