Related papers: Automated algorithms to build Active Galactic Nucl…

X-Ray Evolution of Active Galactic Nuclei and Hierarchical Galaxy Formation

We have incorporated the description of the X-ray properties of Active Galactic Nuclei (AGNs) into a semi-analytic model of galaxy formation, adopting physically motivated scaling laws for accretion triggered by galaxy encounters. Our model…

Astrophysics · Physics 2009-11-10 N. Menci , F. Fiore , G. C. Perola , A. Cavaliere

Euclid Quick Data Release (Q1). First Euclid statistical study of the active galactic nuclei contribution fraction

Active galactic nuclei (AGN) play a key role in galaxy evolution but are challenging to identify due to their varied observational signatures. Furthermore, understanding their impact requires quantifying their strength relative to their…

Astrophysics of Galaxies · Physics 2025-03-20 Euclid Collaboration , B. Margalef-Bentabol , L. Wang , A. La Marca , V. Rodriguez-Gomez , A. Humphrey , S. Fotopoulou , F. Ricci , Y. Toba , G. Stevens , M. Mezcua , W. Roster , J. H. Knapen , M. Salvato , M. Siudek , F. Shankar , T. Matamoro Zatarain , L. Spinoglio , P. Dayal , J. Petley , R. Kondapally , N. Aghanim , B. Altieri , A. Amara , S. Andreon , N. Auricchio , H. Aussel , C. Baccigalupi , M. Baldi , A. Balestra , S. Bardelli , P. Battaglia , A. Biviano , A. Bonchi , D. Bonino , E. Branchini , M. Brescia , J. Brinchmann , S. Camera , G. Cañas-Herrera , V. Capobianco , C. Carbone , J. Carretero , S. Casas , M. Castellano , G. Castignani , S. Cavuoti , K. C. Chambers , A. Cimatti , C. Colodro-Conde , G. Congedo , C. J. Conselice , L. Conversi , Y. Copin , A. Costille , F. Courbin , H. M. Courtois , M. Cropper , A. Da Silva , H. Degaudenzi , G. De Lucia , A. M. Di Giorgio , C. Dolding , H. Dole , F. Dubath , C. A. J. Duncan , X. Dupac , A. Ealet , S. Escoffier , M. Farina , R. Farinelli , F. Faustini , S. Ferriol , F. Finelli , M. Frailis , E. Franceschi , S. Galeotta , K. George , B. Gillis , C. Giocoli , P. Gómez-Alvarez , J. Gracia-Carpio , B. R. Granett , A. Grazian , F. Grupp , L. Guzzo , S. Gwyn , S. V. H. Haugan , W. Holmes , I. M. Hook , F. Hormuth , A. Hornstrup , P. Hudelot , K. Jahnke , M. Jhabvala , E. Keihänen , S. Kermiche , A. Kiessling , B. Kubik , M. Kümmel , M. Kunz , H. Kurki-Suonio , Q. Le Boulc'h , A. M. C. Le Brun , D. Le Mignant , P. Liebing , S. Ligori , P. B. Lilje , V. Lindholm , I. Lloro , G. Mainetti , D. Maino , E. Maiorano , O. Mansutti , S. Marcin , O. Marggraf , M. Martinelli , N. Martinet , F. Marulli , R. Massey , S. Maurogordato , E. Medinaceli , S. Mei , M. Melchior , Y. Mellier , M. Meneghetti , E. Merlin , G. Meylan , A. Mora , M. Moresco , L. Moscardini , R. Nakajima , C. Neissner , S. -M. Niemi , J. W. Nightingale , C. Padilla , S. Paltani , F. Pasian , K. Pedersen , W. J. Percival , V. Pettorino , S. Pires , G. Polenta , M. Poncet , L. A. Popa , L. Pozzetti , F. Raison , R. Rebolo , A. Renzi , J. Rhodes , G. Riccio , E. Romelli , M. Roncarelli , H. J. A. Rottgering , B. Rusholme , R. Saglia , Z. Sakr , D. Sapone , B. Sartoris , J. A. Schewtschenko , P. Schneider , T. Schrabback , A. Secroun , G. Seidel , M. Seiffert , S. Serrano , P. Simon , C. Sirignano , G. Sirri , L. Stanco , J. Steinwagner , P. Tallada-Crespí , A. N. Taylor , I. Tereno , S. Toft , R. Toledo-Moreo , F. Torradeflot , I. Tutusaus , L. Valenziano , J. Valiviita , T. Vassallo , G. Verdoes Kleijn , A. Veropalumbo , Y. Wang , J. Weller , A. Zacchei , G. Zamorani , F. M. Zerbi , I. A. Zinchenko , E. Zucca , V. Allevato , M. Ballardini , M. Bolzonella , E. Bozzo , C. Burigana , R. Cabanac , A. Cappi , D. Di Ferdinando , J. A. Escartin Vigo , L. Gabarra , M. Huertas-Company , J. Martín-Fleitas , S. Matthew , N. Mauri , R. B. Metcalf , A. Pezzotta , M. Pöntinen , C. Porciani , I. Risso , V. Scottez , M. Sereno , M. Tenti , M. Viel , M. Wiesmann , Y. Akrami , I. T. Andika , S. Anselmi , M. Archidiacono , F. Atrio-Barandela , C. Benoist , K. Benson , D. Bertacca , M. Bethermin , L. Bisigello , A. Blanchard , L. Blot , H. Böhringer , S. Borgani , M. L. Brown , S. Bruton , A. Calabro , B. Camacho Quevedo , F. Caro , C. S. Carvalho , T. Castro , F. Cogato , A. R. Cooray , O. Cucciati , S. Davini , F. De Paolis , G. Desprez , A. Díaz-Sánchez , J. J. Diaz , S. Di Domizio , J. M. Diego , P. -A. Duc , A. Enia , Y. Fang , A. G. Ferrari , P. G. Ferreira , A. Finoguenov , A. Fontana , A. Franco , K. Ganga , J. García-Bellido , T. Gasparetto , V. Gautard , R. Gavazzi , E. Gaztanaga , F. Giacomini , F. Gianotti , G. Gozaliasl , M. Guidi , C. M. Gutierrez , A. Hall , W. G. Hartley , S. Hemmati , C. Hernández-Monteagudo , H. Hildebrandt , J. Hjorth , J. J. E. Kajava , Y. Kang , V. Kansal , D. Karagiannis , K. Kiiveri , C. C. Kirkpatrick , S. Kruk , J. Le Graet , L. Legrand , M. Lembo , F. Lepori , G. Leroy , G. F. Lesci , J. Lesgourgues , L. Leuzzi , T. I. Liaudat , S. J. Liu , A. Loureiro , J. Macias-Perez , G. Maggio , M. Magliocchetti , F. Mannucci , R. Maoli , C. J. A. P. Martins , L. Maurin , M. Miluzio , P. Monaco , C. Moretti , G. Morgante , C. Murray , K. Naidoo , A. Navarro-Alsina , S. Nesseris , F. Passalacqua , K. Paterson , L. Patrizii , A. Pisani , D. Potter , S. Quai , M. Radovich , P. -F. Rocci , G. Rodighiero , S. Sacquegna , M. Sahlén , D. B. Sanders , E. Sarpa , C. Scarlata , A. Schneider , D. Sciotti , E. Sellentin , L. C. Smith , K. Tanidis , G. Testera , R. Teyssier , S. Tosi , A. Troja , M. Tucci , C. Valieri , A. Venhola , D. Vergani , G. Verza , P. Vielzeuf , N. A. Walton , D. Scott

Modeling active galactic nuclei: ongoing problems for the faint-end of the luminosity function

We consider simple semi-analytic models that relate the active galactic nuclei (AGN) evolution to the merging history of their host dark matter haloes and quantify their ability of matching the AGN luminosity function and its spatial…

Astrophysics · Physics 2008-11-26 F. Marulli , E. Branchini , L. Moscardini , M. Volonteri

Unveiling the nature of INTEGRAL objects through optical spectroscopy. VIII. Identification of 44 newly detected hard X-ray sources

(abridged) Hard X-ray surveys performed by the INTEGRAL satellite have discovered a conspicuous fraction (up to 30%) of unidentified objects among the detected sources. Here we continue our identification program by selecting probable…

High Energy Astrophysical Phenomena · Physics 2015-05-19 N. Masetti , P. Parisi , E. Palazzi , E. Jimenez-Bailon , V. Chavushyan , L. Bassani , A. Bazzano , A. J. Bird , A. J. Dean , P. A. Charles , G. Galaz , R. Landi , A. Malizia , E. Mason , V. A. McBride , D. Minniti , L. Morelli , F. Schiavone , J. B. Stephen , P. Ubertini

RESOLVE and ECO: Finding Low-Metallicity $z\sim0$ Dwarf AGN Candidates Using Optimized Emission-Line Diagnostics

Existing star-forming vs. active galactic nucleus (AGN) classification schemes using optical emission-line diagnostics mostly fail for low-metallicity and/or highly star-forming galaxies, missing AGN in typical $z\sim0$ dwarfs. To recover…

Astrophysics of Galaxies · Physics 2022-06-01 Mugdha S. Polimera , Sheila J. Kannappan , Chris T. Richardson , Ashley S. Bittner , Carlynn Ferguson , Amanda J. Moffett , Kathleen D. Eckert , Jillian M. Bellovary , Mark A. Norris

Elusive Active Galactic Nuclei

A fraction of active galactic nuclei do not show the classical Seyfert-type signatures in their optical spectra, i.e. they are optically "elusive". X-ray observations are an optimal tool to identify this class of objects. We combine new…

Astrophysics · Physics 2009-11-10 R. Maiolino , A. Comastri , R. Gilli , N. M. Nagar , S. Bianchi , T. Boeker , E. Colbert , A. Krabbe , A. Marconi , G. Matt , M. Salvati

Mergers in Double-Peaked [O III] Active Galactic Nuclei

As a natural consequence of galaxy mergers, binary active galactic nuclei (AGNs) should be commonplace. Nevertheless, observational confirmations are rare, especially for binaries with separations less than ten kpc. Such a system may show…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Hai Fu , Adam D. Myers , S. G. Djorgovski , Lin Yan

Morphology Classification and Photometric Redshift Measurement of Galaxies

Based on the Sloan Digital Sky Survey Data Release 5 Galaxy Sample, we explore photometric morphology classification and redshift estimation of galaxies using photometric data and known spectroscopic redshifts. An unsupervised method,…

Astrophysics · Physics 2009-11-13 Yanxia Zhang , Lili Li , Yongheng Zhao

A New Sample of Gamma-Ray Emitting Jetted Active Galactic Nuclei -- Preliminary Results

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

The incidence of obscuration in active galactic nuclei

We study the incidence of nuclear obscuration on a complete sample of 1310 AGN selected on the basis of their rest-frame 2-10 keV X-ray flux from the XMM-COSMOS survey, in the redshift range 0.3<z<3.5. We classify the AGN as obscured or…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 A. Merloni , A. Bongiorno , M. Brusa , K. Iwasawa , V. Mainieri , B. Magnelli , M. Salvato , S. Berta , N. Cappelluti , A. Comastri , F. Fiore , R. Gilli , A. Koekemoer , E. Le Floc'h , E. Lusso , D. Lutz , T. Miyaji , F. Pozzi , L. Riguccini , D. J. Rosario , J. Silverman , M. Symeonidis , E. Treister , C. Vignali , G. Zamorani

AGN environments: is the viewing angle sufficient to explain the difference between broad-line and narrow-line AGN? -- A low-redshift study of close AGN neighbours. Paper I

The unification of active galactic nuclei (AGN) is a model that has been difficult to test due to the lack of knowledge on the intrinsic luminosities of the objects. We present a test were we probe the model by statistical investigation of…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-05 Beatriz Villarroel , Andreas Korn , Yoshiki Matsuoka

Low Resolution Spectral Templates For AGNs and Galaxies From 0.03 -- 30 microns

We present a set of low resolution empirical SED templates for AGNs and galaxies in the wavelength range from 0.03 to 30 microns based on the multi-wavelength photometric observations of the NOAO Deep-Wide Field Survey Bootes field and the…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 R. J. Assef , C. S. Kochanek , M. Brodwin , R. Cool , W. Forman , A. H. Gonzalez , R. C. Hickox , C. Jones , E. Le Floc'h , J. Moustakas , S. S. Murray , D. Stern

Offset Active Galactic Nuclei as Tracers of Galaxy Mergers and Supermassive Black Hole Growth

Offset active galactic nuclei (AGNs) are AGNs that are in ongoing galaxy mergers, which produce kinematic offsets in the AGNs relative to their host galaxies. Offset AGNs are also close relatives of dual AGNs. We conduct a systematic search…

Astrophysics of Galaxies · Physics 2015-06-19 Julia M. Comerford , Jenny E. Greene

Chandra Survey of Nearby Galaxies: The Catalog

We searched in the public archive of the Chandra X-ray Observatory as of March 2016 and assembled a sample of 719 galaxies within 50 Mpc with ACIS observations available. By cross-correlation with the optical or near-infrared nuclei of…

Astrophysics of Galaxies · Physics 2017-02-08 Rui She , Luis C. Ho , Hua Feng

Euclid Quick Data Release (Q1). Active galactic nuclei identification using diffusion-based inpainting of Euclid VIS images

Light emission from galaxies exhibit diverse brightness profiles, influenced by factors such as galaxy type, structural features and interactions with other galaxies. Elliptical galaxies feature more uniform light distributions, while…

Astrophysics of Galaxies · Physics 2025-10-20 Euclid Collaboration , G. Stevens , S. Fotopoulou , M. N. Bremer , T. Matamoro Zatarain , K. Jahnke , B. Margalef-Bentabol , M. Huertas-Company , M. J. Smith , M. Walmsley , M. Salvato , M. Mezcua , A. Paulino-Afonso , M. Siudek , M. Talia , F. Ricci , W. Roster , N. Aghanim , B. Altieri , S. Andreon , H. Aussel , C. Baccigalupi , M. Baldi , S. Bardelli , P. Battaglia , A. Biviano , A. Bonchi , E. Branchini , M. Brescia , J. Brinchmann , S. Camera , G. Cañas-Herrera , V. Capobianco , C. Carbone , J. Carretero , M. Castellano , G. Castignani , S. Cavuoti , K. C. Chambers , A. Cimatti , C. Colodro-Conde , G. Congedo , C. J. Conselice , L. Conversi , Y. Copin , A. Costille , F. Courbin , H. M. Courtois , M. Cropper , A. Da Silva , H. Degaudenzi , G. De Lucia , C. Dolding , H. Dole , M. Douspis , F. Dubath , X. Dupac , S. Dusini , S. Escoffier , M. Farina , S. Ferriol , K. George , C. Giocoli , B. R. Granett , A. Grazian , F. Grupp , S. V. H. Haugan , I. M. Hook , F. Hormuth , A. Hornstrup , P. Hudelot , M. Jhabvala , E. Keihänen , S. Kermiche , A. Kiessling , M. Kilbinger , B. Kubik , M. Kümmel , H. Kurki-Suonio , Q. Le Boulc'h , A. M. C. Le Brun , D. Le Mignant , P. B. Lilje , V. Lindholm , I. Lloro , G. Mainetti , D. Maino , E. Maiorano , O. Marggraf , M. Martinelli , N. Martinet , F. Marulli , R. Massey , S. Maurogordato , H. J. McCracken , E. Medinaceli , S. Mei , M. Melchior , M. Meneghetti , E. Merlin , G. Meylan , A. Mora , M. Moresco , L. Moscardini , R. Nakajima , C. Neissner , S. -M. Niemi , C. Padilla , S. Paltani , F. Pasian , K. Pedersen , W. J. Percival , V. Pettorino , G. Polenta , M. Poncet , L. A. Popa , L. Pozzetti , F. Raison , R. Rebolo , A. Renzi , J. Rhodes , G. Riccio , E. Romelli , M. Roncarelli , R. Saglia , A. G. Sánchez , D. Sapone , J. A. Schewtschenko , M. Schirmer , P. Schneider , T. Schrabback , A. Secroun , S. Serrano , P. Simon , C. Sirignano , G. Sirri , J. Skottfelt , L. Stanco , J. Steinwagner , P. Tallada-Crespí , A. N. Taylor , I. Tereno , S. Toft , R. Toledo-Moreo , F. Torradeflot , I. Tutusaus , L. Valenziano , J. Valiviita , T. Vassallo , G. Verdoes Kleijn , A. Veropalumbo , Y. Wang , J. Weller , A. Zacchei , G. Zamorani , F. M. Zerbi , I. A. Zinchenko , E. Zucca , V. Allevato , M. Ballardini , M. Bolzonella , E. Bozzo , C. Burigana , R. Cabanac , A. Cappi , J. A. Escartin Vigo , L. Gabarra , W. G. Hartley , J. Martín-Fleitas , S. Matthew , R. B. Metcalf , A. Pezzotta , M. Pöntinen , I. Risso , V. Scottez , M. Sereno , M. Tenti , M. Wiesmann , Y. Akrami , S. Alvi , I. T. Andika , S. Anselmi , M. Archidiacono , F. Atrio-Barandela , D. Bertacca , M. Bethermin , L. Bisigello , A. Blanchard , L. Blot , S. Borgani , M. L. Brown , S. Bruton , A. Calabro , F. Caro , T. Castro , F. Cogato , S. Davini , G. Desprez , A. Díaz-Sánchez , J. J. Diaz , S. Di Domizio , J. M. Diego , P. -A. Duc , A. Enia , Y. Fang , A. G. Ferrari , A. Finoguenov , A. Fontana , A. Franco , J. García-Bellido , T. Gasparetto , V. Gautard , E. Gaztanaga , F. Giacomini , F. Gianotti , M. Guidi , C. M. Gutierrez , A. Hall , S. Hemmati , H. Hildebrandt , J. Hjorth , J. J. E. Kajava , Y. Kang , V. Kansal , D. Karagiannis , C. C. Kirkpatrick , S. Kruk , L. Legrand , M. Lembo , F. Lepori , G. Leroy , J. Lesgourgues , L. Leuzzi , T. I. Liaudat , J. Macias-Perez , M. Magliocchetti , F. Mannucci , R. Maoli , C. J. A. P. Martins , L. Maurin , M. Miluzio , P. Monaco , G. Morgante , K. Naidoo , A. Navarro-Alsina , F. Passalacqua , K. Paterson , L. Patrizii , A. Pisani , D. Potter , S. Quai , M. Radovich , P. -F. Rocci , G. Rodighiero , S. Sacquegna , M. Sahlén , D. B. Sanders , E. Sarpa , A. Schneider , M. Schultheis , D. Sciotti , E. Sellentin , F. Shankar , L. C. Smith , K. Tanidis , G. Testera , R. Teyssier , S. Tosi , A. Troja , M. Tucci , C. Valieri , D. Vergani , G. Verza , N. A. Walton

An XMM-Newton spectral survey of 12 micron selected galaxies. II. Implications for AGN selection and unification

We present a multi-waveband analysis of a 126 galaxy sub-sample of the 12 micron galaxy sample (12MGS), for which we have carried out a detailed X-ray spectral analysis of in a previous paper. We present optical activity classes and we…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Murray Brightman , Kirpal Nandra

Penetrating the Deep Cover of Compton Thick Active Galactic Nuclei

We analyze observations obtained with the Chandra X-ray Observatory of bright Compton thick active galactic nuclei (AGNs), those with column densities in excess of 1.5 x 10^{24} cm^{-2} along the lines of sight. We therefore view the…

Astrophysics · Physics 2011-07-21 N. A. Levenson , T. M. Heckman , J. H. Krolik , K. A. Weaver , P. T. Zycki

EMU/GAMA: A statistical perspective on active galactic nuclei diagnostics

While it is well known that galaxies are composites of many emission processes, quantifying the various contributions remains challenging. In this work, we use unsupervised machine learning based clustering algorithms to evaluate the…

Astrophysics of Galaxies · Physics 2026-03-06 J. Prathap , A. M. Hopkins , R. Carvajal , M. Cowley , S. M. Croom , D. Farrah , I. Prandoni , S. S. Shabala , J. Th. van Loon , C. Pappalardo , K. A. Pimbblet , U. T. Ahmed , M. Bilicki , M. J. I. Brown , D. Leahy , A. Mailvaganam , J. R. Marvil , T. Mukherjee , S. F. Rahman , T. Vernstrom , J. Willingham , T. Zafar

NuSTAR Observations of AGN with Low Observed X-ray to [OIII] Luminosity Ratios: Heavily Obscured AGN or Turned-Off AGN?

Type 2 active galactic nuclei (AGN) show signatures of accretion onto a supermassive black hole through strong, high-ionization, narrow emission lines extended on scales of 100s to 1000s of parsecs, but they lack the broad emission lines…

High Energy Astrophysical Phenomena · Physics 2022-09-21 M. Lynne Saade , Murray Brightman , Daniel Stern , Matthew A. Malkan , Javier A. Garcia

X-ray absorption, nuclear infrared emission and dust covering factors of AGN: testing Unification Schemes

We present the distributions of geometrical covering factors of active galactic nuclei (AGNs) dusty tori (f2) using an X-ray selected complete sample of 227 AGN drawn from the Bright Ultra-hard XMM-Newton Survey. The AGN have z from 0.05 to…

Astrophysics of Galaxies · Physics 2016-03-23 S. Mateos , F. J. Carrera , A. Alonso-Herrero , A. Hernán-Caballero , X. Barcons , A. Asensio Ramos , M. G. Watson , A. Blain , A. Caccianiga , L. Ballo , V. Braito , C. Ramos Almeida