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Related papers: An Active Galactic Nucleus Recognition Model based…

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We present a new method to predict the line-of-sight column density (NH) values of active galactic nuclei (AGN) based on mid-infrared (MIR), soft, and hard X-ray data. We developed a multiple linear regression machine learning algorithm…

Astrophysics of Galaxies · Physics 2023-07-05 Ross Silver , Núria Torres-Alba , Xiurui Zhao , Stefano Marchesi , Andrealuna Pizzetti , Isaiah Cox , Marco Ajello

Deep neural networks (DNN) have shown remarkable success in the classification of physiological signals. In this study we propose a method for examining to what extent does a DNN's performance rely on rediscovering existing features of the…

Machine Learning · Statistics 2020-08-26 Tom Beer , Bar Eini-Porat , Sebastian Goodfellow , Danny Eytan , Uri Shalit

Active Galactic Nuclei (AGN) are powered by the accretion of material onto a supermassive black hole (SMBH), and are among the most luminous objects in the Universe. However, the huge radiative power of most AGN cannot be seen directly, as…

Astrophysics of Galaxies · Physics 2018-10-17 Ryan C. Hickox , David M. Alexander

Modeling the spectral energy distribution (SED) of active galactic nuclei (AGN) plays a very important role in constraining modern cosmological simulations of galaxy formation. Here, we utilize an advanced supermassive black hole (SMBH)…

Astrophysics of Galaxies · Physics 2026-03-23 Tong Su , Qi Guo , Erlin Qiao , Wenxiang Pei , Luis C. Ho , Cedric G. Lacey

We introduce the Mass-Excitation (MEx) diagnostic to identify active galactic nuclei (AGN) in galaxies at intermediate redshift. In the absence of near-infrared spectroscopy, necessary to use traditional nebular line diagrams at z>0.4, we…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Stéphanie Juneau , Mark Dickinson , David M. Alexander , Samir Salim

We have compiled a large sample of low-redshift active galactic nuclei (AGN) identified via their emission line characteristics from the spectroscopic data of the Sloan Digital Sky Survey. Since emission lines are often contaminated by…

Accurate active galactic nucleus (AGN) identifications in large galaxy samples are crucial to assess the role of AGN and AGN feedback in the coevolution of galaxies and their central supermassive black holes. Emission line flux ratio…

Astrophysics of Galaxies · Physics 2023-06-07 Marco Albán , Dominika Wylezalek

We investigate the possible presence of active galactic nuclei (AGN) in dwarf galaxies and other nearby galaxies to identify candidates for follow-up confirmation and dynamical mass measurements. We use the Wide-field Infrared Survey…

Astrophysics of Galaxies · Physics 2017-07-19 Francine R. Marleau , Dominic Clancy , Rebecca Habas , Matteo Bianconi

We present a large sample of infrared-luminous candidate active galactic nuclei (AGNs) that lack X-ray detections in Chandra, XMM-Newton, and NuSTAR fields. We selected all optically detected SDSS sources with redshift measurements,…

Double-peaked [O III]5007, profiles in active galactic nuclei (AGNs) may provide evidence for the existence of dual AGNs, but a good diagnostic for selecting them is currently lacking. Starting from $\sim$ 7000 active galaxies in SDSS DR7,…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 J. -M Wang , Y. -M. Chen , C. Hu , W. -M. Mao , S. Zhang , W. -H. Bian

Among the most extreme objects in the Universe, active galactic nuclei (AGN) are luminous centers of galaxies where a black hole feeds on surrounding matter. The variability patterns of the light emitted by an AGN contain information about…

Instrumentation and Methods for Astrophysics · Physics 2021-06-22 Ji Won Park , Ashley Villar , Yin Li , Yan-Fei Jiang , Shirley Ho , Joshua Yao-Yu Lin , Philip J. Marshall , Aaron Roodman

It is still a matter of intense debate how supermassive black holes (SMBH) grow, and the role played by feedback from active galactic nuclei (AGN) in the co-evolution of SMBHs and galaxies. To test the coevolution proposed by theoretical…

Astrophysics of Galaxies · Physics 2022-11-30 George Mountrichas , Francesco Shankar

Context. A defining characteristic of active galactic nuclei (AGN) that distinguishes them from other astronomical sources is their stochastic variability, which is observable across the entire electromagnetic spectrum. Upcoming optical…

We describe an Artificial Neural Network (ANN) approach to classification of galaxy images and spectra. ANNs can replicate the classification of galaxy images by a human expert to the same degree of agreement as that between two human…

Astrophysics · Physics 2007-05-23 Ofer Lahav

We have developed an efficient Active Galactic Nucleus (AGN) selection method using 18-band Spectral Energy Distribution (SED) fitting in mid-infrared (mid-IR). AGNs are often obscured by gas and dust, and those obscured AGNs tend to be…

Astrophysics of Galaxies · Physics 2017-08-29 Ting-Chi Huang , Tomotsugu Goto , Tetsuya Hashimoto , Nagisa Oi , Hideo Matsuhara

We describe an algorithm to decompose deep images of Active Galactic Nuclei into host galaxy and nuclear components. Currently supported are three galaxy models: A de-Vaucouleurs spheroidal, an exponential disc, and a two-component…

Astrophysics · Physics 2009-11-10 B. Kuhlbrodt , L. Wisotzki , K. Jahnke

Active galactic nuclei (AGN) are powered by the accretion of disks of gas onto supermassive black holes (SMBHs). Stars and stellar remnants orbiting the SMBH in the nuclear star cluster (NSC) will interact with the AGN disk. Orbiters…

Astrophysics of Galaxies · Physics 2020-11-02 Gaia Fabj , Syeda S. Nasim , Freddy Caban , K. E. Saavik Ford , Barry McKernan , Jillian M. Bellovary

Over the last five decades, AGN studies have produced a number of spectacular examples of synergies and multifaceted approaches in astrophysics. The field of AGN research now spans the entire spectral range and covers more than twelve…

Astrophysics · Physics 2015-06-24 Andrei P. Lobanov , J. Anton Zensus

A semi-empirical model is presented that describes the distribution of Active Galactic Nuclei (AGN) on the cosmic web. It populates dark-matter halos in N-body simulations (MultiDark) with galaxy stellar masses using empirical relations…

High Energy Astrophysical Phenomena · Physics 2018-12-26 A. Georgakakis , J. Comparat , A. Merloni , L. Ciesla , J. Aird , A. Finoguenov

The finding of active galactic nuclei (AGN) in dwarf galaxies has important implications for galaxy evolution and supermassive black hole formation models. Yet, how AGN in dwarf galaxies form is still debated, in part due to scant…

Astrophysics of Galaxies · Physics 2024-02-12 M. Mezcua , H. Domínguez Sánchez