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相关论文: Active galactic nuclei catalog from the AKARI NEP …

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I present a review of X-ray and mid-IR surveys for Compton-thick Active Galactic Nuclei (AGN). These are the most highly obscured sources having hydrogen column densities >1.5x10^24 cm-2. Key surveys in the local Universe are presented…

宇宙学与河外天体物理 · 物理学 2015-06-04 I. Georgantopoulos

One of the most peculiar characteristics of Active Galactic Nuclei (AGN) is their variability over all wavelengths. This property has been used in the past to select AGN samples and is foreseen to be one of the detection techniques applied…

Optical variability has proven to be an effective way of detecting AGNs in imaging surveys, lasting from weeks to years. In the present work we test its use as a tool to identify AGNs in the VST multi-epoch survey of the COSMOS field,…

In order to find a fast and reliable method for selecting metal poor galaxies (MPGs), especially in large surveys and huge database, an Artificial Neural Network (ANN) method is applied to a sample of star-forming galaxies from the Sloan…

星系天体物理 · 物理学 2015-06-18 F. Shi , Y-Y. Liu , X. Kong , Y. Chen

The efficiency of mid-infrared selection methods for finding obscured AGN is investigated using data in the \chandra Deep Field North. It is shown that samples of AGN candidates compiled on the basis of mid-infrared colours only suffer…

天体物理学 · 物理学 2009-11-13 I. Georgantopoulos , A. Georgakakis , M. Rowan-Robinson , E. Rovilos

Active galactic nuclei (AGN) are supermassive black holes with luminous accretion disks found in some galaxies, and are thought to play an important role in galaxy evolution. However, traditional optical spectroscopy for identifying AGN…

星系天体物理 · 物理学 2022-12-16 Ziting Guo , John F. Wu , Chelsea E. Sharon

Revealing what fraction of galaxies harbor AGN is central in understanding black hole accretion history of the Universe. However, optical and soft X-ray surveys miss the most highly obscured AGNs. Infrared (IR), instead, is more robust…

星系天体物理 · 物理学 2019-03-20 Chia-Ying Chiang , Tomotsugu Goto , Tetsuya Hashimoto , Seong-Jin Kim , Hideo Matsuhara , Nagisa Oi

A complete demographic of active galactic nuclei (AGN) is essential to understand the evolution of the Universe. Optical surveys estimate the population of AGN in the local Universe to be of $\sim$ 4%. However, these results could be biased…

The second Fermi-LAT source catalog (2FGL) is the deepest all-sky survey available in the gamma-ray band. It contains 1873 sources, of which 576 remain unassociated. Machine-learning algorithms can be trained on the gamma-ray properties of…

高能天体物理现象 · 物理学 2014-01-29 M. Doert , M. Errando

We present a photometric catalog for Spitzer Space Telescope warm mission observations of the North Ecliptic Pole (NEP; centered at $\rm R.A.=18^h00^m00^s$, $\rm Decl.=66^d33^m38^s.552$). The observations are conducted with IRAC in 3.6…

We demonstrate a newly developed mid-infrared planetary nebula (PN) selection technique. It is designed to enable efficient searches for obscured, previously unknown, PN candidates present in the photometric source catalogues of Galactic…

We study the host galaxy properties of radio sources in the AKARI-North Ecliptic Pole (NEP) field, using an ensemble of multi-wavelength datasets. We identify both radio-loud and radio-quiet AGN and study their host galaxy properties by…

宇宙学与河外天体物理 · 物理学 2015-06-12 Marios Karouzos , Myungshin Im , Markos Trichas , the AKARI-NEP team

We investigated AGN activity in low-mass galaxies, an important regime that can shed light onto BH formation and evolution, and their interaction with their host galaxies. We identified 336 AGN candidates from a parent sample of $\sim…

While emission-line flux ratio diagnostics are the most common technique for identifying active galactic nuclei (AGNs) in optical spectra, applying this approach to single fiber spectra of galaxies can omit entire subpopulations of AGNs.…

An incremental version of the fourth catalog of active galactic nuclei (AGNs) detected by the Fermi-Large Area Telescope is presented. This version (4LAC-DR3) derives from the third data release of the 4FGL catalog based on 12 years of E>50…

高能天体物理现象 · 物理学 2023-01-25 LAT collaboration , Marco Ajello , Luca Baldini , Jean Ballet , Denis Bastieri , Josefa Becerra Gonzalez , Ronaldo Bellazzini , Alessandra Berretta , Elisabetta Bissaldi , Raffaella Bonino , Ari Brill , Philippe Bruel , Sara Buson , Regina Caputo , Patrizia Caraveo , Teddy Cheung , Graziano Chiaro , Nicolo Cibrario , Stefano Ciprini , Milena Crnogorcevic , Sara Cutini , Filippo D'Ammando , Salvatore De Gaetano , Niccolo Di Lalla , Leonardo Di Venere , Alberto Dominguez , Vandad Fallah Ramazani , Elizabeth Ferrara , Alessio Fiori , Yasushi Fukazawa , Stefan Funk , Piergiorgio Fusco , Viviana Gammaldi , Fabio Gargano , Simone Garrappa , Dario Gasparrini , Nico Giglietto , Francesco Giordano , Marcello Giroletti , David Green , Isabelle Grenier , Sylvain Guiriec , Deirdre Horan , Xian Hou , Taishu Kayanoki , Michael Kuss , Stefan Larsson , Luca Latronico , Tiffany Lewis , Jian Li , Ioannis Liodakis , Francesco Longo , Francesco Loparco , Benoit Lott , Michael Lovellette , Pasquale Lubrano , Grzegorz Madejski , Simone Maldera , Alberto Manfreda , Guillem Marti-Devesa , Mario Nicola Mazziotta , Isabella Mereu , Peter Michelson , Nestor Mirabal , Warit Mitthumsiri , Tsunefumi Mizuno , Maria Elena Monzani , Aldo Morselli , Igor Moskalenko , Michela Negro , Roopesh Ojha , Monica Orienti , Elena Orlando , Jonathan F. Ormes , Zhiyuan Pei , Harold A. Pena-Herazo , Massimo Persic , Melissa Pesce-Rollins , Vahe Petrosian , Roberta Pillera , Helen Poon , Troy Porter , Giacomo Principe , Silvia Raino , Riccardo Rando , Bindu Rani , Massimiliano Razzano , Soebur Razzaque , Anita Reimer , Olaf Reimer , Jeff Scargle , Lorenzo Scotton , Davide Serini , Carmelo Sgro , Eric J. Siskind , Gloria Spandre , Paolo Spinelli , Dan Suson , Hiro Tajima , Diego F. Torres , Janeth Valverde , Hend Yassin , Gabrijela Zaharijas

X-ray emission detection in a galaxy is one of the efficient tools for selecting Active Galactic Nuclei (AGNs). However, many X-ray-selected AGNs are not easily selected as AGNs by their optical emission. These galaxies, so-called optically…

星系天体物理 · 物理学 2022-03-31 Itsna K. Fitriana , Takashi Murayama

We present the first Active Galactic Nuclei (AGN) catalog in the Hobby-Eberly Telescope Dark Energy Experiment Survey (HETDEX) observed between January 2017 and June 2020. HETDEX is an ongoing spectroscopic survey with no pre-selection…

(Abridged) Many classes of active galactic nuclei (AGN) have been defined entirely throughout optical wavelengths while the X-ray spectra have been very useful to investigate their inner regions. However, optical and X-ray results show many…

We use machine learning techniques to investigate their performance in classifying active galactic nuclei (AGNs), including X-ray selected AGNs (XAGNs), infrared selected AGNs (IRAGNs), and radio selected AGNs (RAGNs). Using known physical…

Context. A series of studies have demonstrated that the Gaia multipeak method (GMP) is a very efficient technique to select active galactic nucleus (AGN) pair candidates. The number of candidates is determined by the size of the input AGN…

星系天体物理 · 物理学 2024-12-11 Qiqi Wu , M. Scialpi , Shilong Liao , F. Mannucci , Zhaoxiang Qi