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Related papers: Stellar flare detection in XMM-Newton with gradien…

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Machine learning based approaches are emerging as very powerful tools for many applications including source classification in astrophysics research due to the availability of huge high quality data from different surveys in observational…

High Energy Astrophysical Phenomena · Physics 2023-07-05 A. Tolamatti , K. K. Singh , K. K. Yadav

Over the past years, thousands of stellar flares have been detected by harvesting data from large photometric surveys. These detections, however, do not account for potential sources of contamination such as background stars appearing in…

This work is part of a systematic X-ray survey of the Taurus star forming complex with XMM-Newton. We study the time series of all X-ray sources associated with Taurus members, to statistically characterize their X-ray variability, and…

Astrophysics · Physics 2009-11-11 B. Stelzer , E. Flaccomio , K. Briggs , G. Micela , L. Scelsi , M. Audard , I. Pillitteri , M. Guedel

Mass loss is a key aspect of stellar evolution, particularly in evolved massive stars, yet episodic mass loss remains poorly understood. To investigate this, we need evolved massive stellar populations across various galactic environments.…

Despite the growing number of gamma-ray sources detected by Fermi-LAT, about one third of the sources in each survey remains of uncertain type. We present a new deep neural network approach for the classification of unidentified or…

High Energy Astrophysical Phenomena · Physics 2021-09-28 Thorben Finke , Michael Krämer , Silvia Manconi

The EXTraS project (Exploring the X-ray Transient and variable Sky) will harvest the hitherto unexplored temporal domain information buried in the serendipitous data collected by the European Photon Imaging Camera (EPIC) instrument onboard…

High Energy Astrophysical Phenomena · Physics 2019-08-15 A. De Luca , R. Salvaterra , A. Tiengo , D. D'Agostino , M. G. Watson , F. Haberl , J. Wilms

This paper explores the application of machine learning methods for classifying astronomical sources using photometric data, including normal and emission line galaxies (ELGs; starforming, starburst, AGN, broad line), quasars, and stars. We…

Aims : Following the advent of increasingly sensitive X-ray observatories, deep observations of early-type stars became possible. However, the results for only a few objects or clusters have until now been reported and there has been no…

Solar and Stellar Astrophysics · Physics 2015-05-13 Yael Naze

A large number of unidentified sources found by astronomical surveys and other observations necessitate the use of an automated classification technique based on machine learning methods. The aim of this paper is to find a suitable…

High Energy Astrophysical Phenomena · Physics 2023-02-20 Shivam Kumaran , Samir Mandal , Sudip Bhattacharyya , Deepak Mishra

Galaxy clusters appear as extended sources in XMM-Newton images, but not all extended sources are clusters. So, their proper classification requires visual inspection with optical images, which is a slow process with biases that are almost…

We present photometric redshifts and spectral energy distribution (SED) classifications for a sample of 1542 optically identified sources detected with XMM in the COSMOS field. Our template fitting classifies 46 sources as stars and 464 as…

Stellar flares are abundant in space photometric light curves. As they are now available in large enough numbers, the statistical study of their overall temporal morphology is timely. We use light curves from the Transiting Exoplanet Survey…

Solar and Stellar Astrophysics · Physics 2025-02-12 Bálint Seli , Krisztián Vida , Katalin Oláh , Anna Görgei , Szabolcs Soós , András Pál , Levente Kriskovics , Zsolt Kővári

We present a Bayesian-odds-ratio-based algorithm for detecting stellar flares in light curve data. We assume flares are described by a model in which there is a rapid rise with a half-Gaussian profile, followed by an exponential decay. Our…

Solar and Stellar Astrophysics · Physics 2015-06-19 M. Pitkin , D. Williams , L. Fletcher , S. D. T. Grant

Time-resolved databases with large spatial coverage are quickly becoming a standard tool for all types of astronomical studies. We report preliminary results from our search for stellar flares in the 2MASS calibration fields. A sample of…

Solar and Stellar Astrophysics · Physics 2015-03-17 James R. A. Davenport , Andrew C. Becker , Suzanne L. Hawley , Adam F. Kowalski , Branimir Sesar , Roc M. Cutri

We present photometric redshifts for 1,031 X-ray sources in the X-ATLAS field, using the machine learning technique TPZ (Carrasco Kind & Brunner 2013). X-ATLAS covers 7.1 deg2 observed with the XMM-Newton within the Science Demonstration…

Astrophysics of Galaxies · Physics 2017-12-06 G. Mountrichas , A. Corral , V. A. Masoura , I. Georgantopoulos , A. Ruiz , A. Georgakakis , F. J. Carrera , S. Fotopoulou

Variable stars play a key role in understanding the Milky Way and the universe. The era of astronomical big data presents new challenges for quick identification of interesting and important variable stars. Accurately estimating the periods…

Instrumentation and Methods for Astrophysics · Physics 2022-12-21 Xiao-Hui Xu , Qing-Feng Zhu , Xu-Zhi Li , Bin Li , Hang Zheng , Jin-Sheng Qiu , Hai-Bin Zhao

Quasars exhibit stochastic variability across wavelengths, typically well described by a Damped Random Walk (DRW). Occasionally, however, they undergo extreme luminosity changes--known as flares--that represent significant departures from…

Instrumentation and Methods for Astrophysics · Physics 2026-04-15 Atal Agrawal

In this work we present the results of the survey carried out on one of the deepest X-ray fields observed by the XMM-Newton satellite. The 1.75 Ms Ultra Narrow Deep Field (XMM175UNDF) survey is made by 13 observations taken over 2 years…

Astrophysics of Galaxies · Physics 2021-09-29 M. Elías-Chávez , A. L. Longinotti , Y. Krongold , C. Vignali , F. Nicastro , D. Rosa-González , Y. D. Mayya , S. Mathur

We present a comprehensive re-analysis of stellar photometric variability in the field of the open cluster M37 following the application of a new photometry and de-trending method to MMT/Megacam image archive. This new analysis allows a…

Solar and Stellar Astrophysics · Physics 2015-05-19 S. -W. Chang , Y. -I. Byun , J. D. Hartman

The statistical characteristic of stellar flares at optical bands has received an extensive study, but it remains to be studied at soft X-ray bands, in particular for solar-type stars. Here, we present a statistical study of soft X-ray…

Solar and Stellar Astrophysics · Physics 2024-01-19 Zhanhao Zhao , Ziqian Hua , Xin Cheng , Zhiyuan Li , Mingde Ding