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Related papers: Predicting the redshift of gamma-ray loud AGNs usi…

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In this paper, we discuss an artificial intelligence based approach to constrain the redshift of blazars using combined $\gamma$--ray observations from the \emph{Fermi} Large Area Telescope (LAT) and ground based atmospheric Cherenkov…

High Energy Astrophysical Phenomena · Physics 2019-11-26 K K Singh , V K Dhar , P J Meintjes

Machine learning techniques offer a precious tool box for use within astronomy to solve problems involving so-called big data. They provide a means to make accurate predictions about a particular system without prior knowledge of the…

Instrumentation and Methods for Astrophysics · Physics 2019-01-01 J. Elliott , R. S. de Souza , A. Krone-Martins , E. Cameron , E. E. O. Ishida , J. Hilbe

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

Extragalactic radio continuum surveys play an increasingly more important role in galaxy evolution and cosmology studies. While radio galaxies and radio quasars dominate at the bright end, star-forming galaxies (SFGs) and radio-quiet Active…

We use nine years of gamma-ray data provided by the Fermi Large Area Telescope (LAT) to systematically study the light curves of more than two thousand active galactic nuclei (AGN) included in recent Fermi-LAT catalogs. Ten different…

High Energy Astrophysical Phenomena · Physics 2020-07-01 P. Peñil , A. Domínguez , S. Buson , M. Ajello , J. Otero-Santos , J. A. Barrio , R. Nemmen , S. Cutini , B. Rani , A. Franckowiak , E. Cavazzuti

Classification of sources is one of the most important tasks in astronomy. Sources detected in one wavelength band, for example using gamma rays, may have several possible associations in other wavebands, or there may be no plausible…

High Energy Astrophysical Phenomena · Physics 2022-04-19 Aakash Bhat , Dmitry Malyshev

Machine-learning (ML) algorithms will play a crucial role in studying the large datasets delivered by new facilities over the next decade and beyond. Here, we investigate the capabilities and limits of such methods in finding galaxies with…

Instrumentation and Methods for Astrophysics · Physics 2019-08-22 Andreas L. Faisst , Abhishek Prakash , Peter L. Capak , Bomee Lee

X-rays offer a reliable method to identify Active Galactic Nuclei (AGN). However, in the high-redshift Universe X-ray AGN are poorly sampled due to their relatively low space density and the small areas covered by X-ray surveys. In addition…

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

We calculate photometric redshifts from the Sloan Digital Sky Survey Data Release 2 Galaxy Sample using artificial neural networks (ANNs). Different input patterns based on various parameters (e.g. magnitude, color index, flux information)…

Astrophysics · Physics 2007-05-23 Lili Li , Yanxia Zhang , Yongheng Zhao , Dawei Yang

Almost all massive galaxies today are understood to contain supermassive black holes (SMBH) at their centers. SMBHs grew by accreting material from their surroundings, emitting X-rays as they did so. X-ray Luminosity Functions (XLFs) of…

Astrophysics of Galaxies · Physics 2023-01-16 Ahlam Alqasim , Mat J. Page

In this paper we discuss an application of machine learning based methods to the identification of candidate AGN from optical survey data and to the automatic classification of AGNs in broad classes. We applied four different machine…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-14 Stefano Cavuoti , Massimo Brescia , Raffaele D'Abrusco , Giuseppe Longo , Maurizio Paolillo

Active Galactic Nuclei (AGN) sources feature supermassive black holes that launch relativistic plasma jets. They are key $\gamma$-ray sources providing a unique laboratory for studying extreme particle acceleration and plasma physics.…

High Energy Astrophysical Phenomena · Physics 2026-02-03 Luana Passos-Reis , Elisabete M. de Gouveia Dal Pino , Tarek Hassan , Santiago Pita , Alberto Domínguez

Computing photo-z for AGN is challenging, primarily due to the interplay of relative emissions associated with the SMBH and its host galaxy. SED fitting methods, effective in pencil-beam surveys, face limitations in all-sky surveys with…

All-sky radio surveys are set to revolutionise the field with new discoveries. However, the vast majority of the tens of millions of radio galaxies won't have the spectroscopic redshift measurements required for a large number of science…

Instrumentation and Methods for Astrophysics · Physics 2022-03-01 Kieran J. Luken , Ray P. Norris , Laurence A. F. Park , X. Rosalind Wang , Miroslav D. Filipovic

A majority of the active galactic nuclei (AGN) in the local Universe are classified as low-luminosity AGN (LLAGN), having bolometric luminosities $\lesssim 10^{42} \ \mathrm{erg \ s^{-1}}$. Although high-energy gamma-ray emission is…

High Energy Astrophysical Phenomena · Physics 2026-04-08 Chris Karwin , Nikita Khatiya , Margot Boughelilba , Xiurui Zhao , Anita Reimer , Marco Ajello

The second catalog of active galactic nuclei (AGNs) detected by the Fermi Large Area Telescope (LAT) in two years of scientific operation is presented. The Second LAT AGN Catalog (2LAC) includes 1017 gamma-ray sources located at high…

High Energy Astrophysical Phenomena · Physics 2015-05-30 LAT Collaboration

Identifying active galactic nuclei (AGN) is extremely important for understanding galaxy evolution and its connection with the assembly of supermassive black holes (SMBH). With the advent of deep and high angular resolution imaging surveys…

Astrophysics of Galaxies · Physics 2026-02-18 Berta Margalef-Bentabol , Lingyu Wang , Antonio La Marca , Vicente Rodriguez-Gomez

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

We present a composite machine learning framework to estimate posterior probability distributions of bulge-to-total light ratio, half-light radius, and flux for Active Galactic Nucleus (AGN) host galaxies within $z<1.4$ and $m<23$ in the…