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Related papers: Periodicity detection in AGN with the boosted tree…

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We evaluate the performance of four different machine learning (ML) algorithms: an Artificial Neural Network Multi-Layer Perceptron (ANN MLP ), Adaboost, Gradient Boosting Classifier (GBC), XGBoost, for the separation of pulsars from radio…

Instrumentation and Methods for Astrophysics · Physics 2018-03-06 Suryarao Bethapudi , Shantanu Desai

The operating state of bearing directly affects the performance of rotating machinery and how to accurately and decisively extract features from the original vibration signal and recognize the faulty parts as early as possible is very…

Signal Processing · Electrical Eng. & Systems 2021-12-03 Haiquan Wang , Wenxuan Yue , Shengjun Wen , Xiaobin Xu , Menghao Su , Shanshan Zhang , Panpan Du

{We focus on characterizing the high-energy emission mechanisms of blazars by analyzing the variability in the radio band of the light curves of more than a thousand sources. We are interested in assigning complexity parameters to these…

Data Analysis, Statistics and Probability · Physics 2022-05-11 Belén Acosta-Tripailao , Walter Max-Moerbeck , Denisse Pastén , Pablo S. Moya

The bright low-mass X-ray binary (LMXB) GX 13+1 is one of the most peculiar Galactic binary systems. A periodicity of 24.27 d with a formal statistical error of 0.03 d was observed in its power spectrum density obtained with RXTE All Sky…

High Energy Astrophysical Phenomena · Physics 2015-06-17 R. Iaria , T. Di Salvo , L. Burderi , A. Riggio , A. D'Ai , N. R. Robba

Context. The nature of X-shaped sources is a matter of considerable debate in the literature: it has even been proposed that they provide evidence for black-hole-mergers/spin-reorientation, and therefore constrain the rate of strong…

The variability of the high-frequency peaked BL Lac object PKS 2155-304 is studied using almost 10 years of optical, X-ray and gamma-rays data. Publicly available data have been gathered and analyzed with the aim to characterize the…

High Energy Astrophysical Phenomena · Physics 2019-01-16 J. Chevalier , D. A. Sanchez , P. D. Serpico , J. -P. Lenain , G. Maurin

In today's era, a tremendous amount of data is generated by different observatories and manual classification of data is something which is practically impossible. Hence, to classify and categorize the objects there are multiple machine and…

Instrumentation and Methods for Astrophysics · Physics 2023-01-03 Sarvesh Gharat , Bhaskar Bose

We used the 1.4 GHz NVSS to study radio sources in two color-selected QSO samples: a volume-limited sample of 1313 QSOs defined by M_i < -23 in the redshift range 0.2 < z < 0.45 and a magnitude-limited sample of 2471 QSOs with m_r < 18.5…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 J. J. Condon , K. I. Kellermann , Amy E. Kimball , Zeljko Ivezic , R. A. Perley

Machine learning algorithms are now being extensively used in our daily lives, spanning across diverse industries as well as academia. In the field of high energy physics (HEP), the most common and challenging task is separating a rare…

High Energy Physics - Phenomenology · Physics 2025-07-23 Arghya Choudhury , Arpita Mondal , Subhadeep Sarkar

We present results from daily radio continuum observations of the Bootes field as part of the Pi GHz Sky Survey (PiGSS). These results are part of a systematic and unbiased campaign to characterize variable and transient sources in the…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Geoffrey C. Bower , David Whysong , Samantha Blair , Steve Croft , Garrett Keating , Casey Law , Peter K. G. Williams , Melvyn C. H. Wright

Ongoing and future surveys with repeat imaging in multiple bands are producing (or will produce) time-spaced measurements of brightness, resulting in the identification of large numbers of variable sources in the sky. A large fraction of…

Instrumentation and Methods for Astrophysics · Physics 2017-11-29 Abhijit Saha , A. Katherina Vivas

We study the space density evolution of active galactic nuclei (AGN) using the $610 \ \mathrm{MHz}$ radio survey of the XXL-North field, performed with the Giant Metrewave Radio Telescope (GMRT). The survey covers an area of $30.4 \…

Despite their theoretical appeal, totally corrective boosting methods based on linear programming have received limited empirical attention. In this paper, we conduct the first large-scale experimental study of six LP-based boosting…

Machine Learning · Computer Science 2025-12-22 Fabian Akkerman , Julien Ferry , Christian Artigues , Emmanuel Hebrard , Thibaut Vidal

Remnant radio galaxies represent the dying phase of radio-loud active galactic nuclei (AGN). Large samples of remnant radio galaxies are important for quantifying the radio galaxy life cycle. The remnants of radio-loud AGN can be identified…

We developed and trained a pipeline of three machine learning (ML) models than can predict which sources are more likely to be an AGN and to be detected in specific radio surveys. Also, it can estimate redshift values for predicted…

The Gaussian phase noise of intensity time series is demonstrated to be drastically reduced when the raw voltage data are digitally filtered through an arbitrarily large number $n$ of orthornormal bandpass profiles (eigen-filters) sharing…

Instrumentation and Methods for Astrophysics · Physics 2020-08-26 Richard Lieu , Kristen Lackeos

Simulations predict that supermassive black hole binaries (SMBHBs) will exhibit periodic brightness variations that may exceed the stochastic variability intrinsic to active galactic nuclei (AGN). In this paper, we simulate SMBHBs with…

Astrophysics of Galaxies · Physics 2026-01-23 Sebastian Banaszak , Caitlin Witt , Adam Miller

This paper compares the performances of three supervised machine learning algorithms in terms of predictive ability and model interpretation on structured or tabular data. The algorithms considered were scikit-learn implementations of…

Machine Learning · Statistics 2022-05-06 Alice J. Liu , Arpita Mukherjee , Linwei Hu , Jie Chen , Vijayan N. Nair

The survey of the COSMOS field by the VLT Survey Telescope is an appealing testing ground for variability studies of active galactic nuclei (AGN). With 54 r-band visits over 3.3 yr and a single-visit depth of 24.6 r-band mag, the dataset is…

Astrophysics of Galaxies · Physics 2021-01-27 D. De Cicco , F. E. Bauer , M. Paolillo , S. Cavuoti , P. Sánchez-Sáez , W. N. Brandt , G. Pignata , M. Vaccari , M. Radovich
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