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With the advancement of technology, machine learning-based analytical methods have pervaded nearly every discipline in modern studies. Particularly, a number of methods have been employed to estimate the redshift of gamma-ray loud active…

High Energy Astrophysical Phenomena · Physics 2023-12-13 Sarvesh Gharat , Abhimanyu Borthakur , Gopal Bhatta

AGNs are very powerful galaxies characterized by extremely bright emissions coming out from their central massive black holes. Knowing the redshifts of AGNs provides us with an opportunity to determine their distance to investigate…

The latest $\textit{Fermi}$-LAT gamma-ray catalog, 4FGL-DR3, presents a large fraction of sources without clear association to known counterparts, i.e., unidentified sources (unIDs). In this paper, we aim to classify them using machine…

High Energy Astrophysical Phenomena · Physics 2023-04-03 Javier Coronado-Blázquez

Measuring the redshift of active galactic nuclei (AGNs) requires the use of time-consuming and expensive spectroscopic analysis. However, obtaining redshift measurements of AGNs is crucial as it can enable AGN population studies, provide…

The Fermi Gamma-ray Space Telescope is producing the most detailed inventory of the gamma-ray sky to date. Despite tremendous achievements approximately 25% of all Fermi extragalactic sources in the Second Fermi LAT Catalogue (2FGL) are…

High Energy Astrophysical Phenomena · Physics 2012-12-12 T. Hassan , N. Mirabal , J. L. Contreras , I. Oya

We apply a number of statistical and machine learning techniques to classify and rank gamma-ray sources from the Third Fermi Large Area Telescope (LAT) Source Catalog (3FGL), according to their likelihood of falling into the two major…

High Energy Astrophysical Phenomena · Physics 2016-03-23 P. M. Saz Parkinson , H. Xu , P. L. H. Yu , D. Salvetti , M. Marelli , A. D. Falcone

Gamma-ray bursts (GRBs) are spectacularly energetic events, with the potential to inform on the early universe and its evolution, once their redshifts are known. Unfortunately, determining redshifts is a painstaking procedure requiring…

Machine learning is an automatic technique that is revolutionizing scientific research, with innovative applications and wide use in astrophysics. The aim of this study was to developed an optimized version of an Artificial Neural Network…

High Energy Astrophysical Phenomena · Physics 2020-06-26 Miloš Kovačević , Graziano Chiaro , Sara Cutini , Gino Tosti

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

Since 2008 August the Fermi Large Area Telescope (LAT) has provided continuous coverage of the gamma-ray sky yielding more than 5000 gamma-ray sources, but 54% of the detected sources remain with no certain or unknown association with a low…

High Energy Astrophysical Phenomena · Physics 2020-12-01 Chiaro G. , Kovacevic M. , La Mura G

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

We have investigated a number of factors that can have significant impacts on the classification performance of $\gamma$-ray sources detected by Fermi Large Area Telescope (LAT) with machine learning techniques. We show that a framework of…

Instrumentation and Methods for Astrophysics · Physics 2020-01-29 Shengda Luo , Alex P. Leung , C. Y. Hui , K. L. Li

The extragalactic high-energy $\gamma$-ray sky is dominated by blazars, which are active galactic nuclei with their jets pointing towards us. Distance measurements are of fundamental importance yet for some of these sources are challenging…

High Energy Astrophysical Phenomena · Physics 2023-11-13 A. Domínguez , M. Láinez , V. S. Paliya , N. Álvarez-Crespo , M. Ajello , J. Finke , M. Nievas-Rosillo , J. L. Contreras , A. Desai

A new approach to estimating photometric redshifts - using Artificial Neural Networks (ANNs) - is investigated. Unlike the standard template-fitting photometric redshift technique, a large spectroscopically-identified training set is…

Astrophysics · Physics 2009-11-07 Andrew E. Firth , Ofer Lahav , Rachel S. Somerville

The accurate estimation of photometric redshifts plays a crucial role in accomplishing science objectives of the large survey projects. The template-fitting and machine learning are the two main types of methods applied currently. Based on…

Machine learning has emerged as a powerful tool in the field of gamma-ray astrophysics. The algorithms can distinguish between different source types, such as blazars and pulsars, and help uncover new insights into the high-energy universe.…

High Energy Astrophysical Phenomena · Physics 2024-01-05 Gopal Bhatta , Sarvesh Gharat , Abhimanyu Borthakur , Aman Kumar

Gamma-Ray Bursts (GRBs), due to their high luminosities are detected up to redshift 10, and thus have the potential to be vital cosmological probes of early processes in the universe. Fulfilling this potential requires a large sample of…

It is known that the soft tail of the gamma-ray bursts' spectra show excesses from the exact power-law dependence. In this article we show that this departure can be detected in the peak flux ratios of different BATSE DISCSC energy…

Astrophysics · Physics 2009-11-07 Z. Bagoly , I. Csabai , A. Mészáros , P. Mészáros , I. Horváth , L. G. Balázs , R. Vavrek

Measuring distances of cosmological sources such as galaxies, stars and quasars plays an increasingly critical role in modern cosmology. Obtaining the optical spectrum and consequently calculating the redshift as a distance indicator could…

Astrophysics of Galaxies · Physics 2022-01-13 Aidin Momtaz , Mohammad Hossein Salimi , Soroush Shakeri

We are compiling a new list of gamma-ray jetted active galactic nuclei (AGN), starting from the fourth catalog of point sources of the Fermi Large Area Telescope (LAT). Our aim is to prepare a list of jetted AGN with known redshifts and…

High Energy Astrophysical Phenomena · Physics 2021-10-06 L. Foschini , M. L. Lister , S. Antón , M. Berton , S. Ciroi , M. J. M. Marchã , M. Tornikoski , E. Järvelä , P. Romano , S. Vercellone , E. Dalla Bontà
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