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

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We investigate the characteristics of the gamma-ray signal following the decay of MeV-scale Axion-Like Particles (ALPs) coupled to photons which are produced in a Supernova (SN) explosion. This analysis is the first to include the…

High Energy Astrophysical Phenomena · Physics 2023-08-03 Eike Müller , Francesca Calore , Pierluca Carenza , Christopher Eckner , M. C. David Marsh

ATLAS (Australia Telescope Large Area Survey) is a wide deep radio survey which is distinguished by its comprehensive multi-wavelength approach. ATLAS is creating a large dataset of radio-selected galaxies for studying the evolution and…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Ray P. Norris , the ATLAS team

Studies of the high-redshift rest-frame ultraviolet (UV) luminosity functions (LFs) have typically treated the star-forming galaxy and active galactic nuclei (AGN) populations separately, as they have different survey depth and area…

Astrophysics of Galaxies · Physics 2022-10-26 Steven L. Finkelstein , Micaela B. Bagley

The properties of the host galaxies of a well-defined sample of 2215 radio-loud AGN with redshifts 0.03 < z < 0.3, defined from the SDSS, are investigated. These are predominantly low radio luminosity sources, with 1.4GHz luminosities of…

Astrophysics · Physics 2008-11-26 P. N. Best , G. Kauffmann , T. M. Heckman , J. Brinchmann , S. Charlot , Z. Ivezic , S. D. M. White

We present a machine learning model to classify Active Galactic Nuclei (AGN) and galaxies (AGN-galaxy classifier) and a model to identify type 1 (optically unabsorbed) and type 2 (optically absorbed) AGN (type 1/2 classifier). We test…

Astrophysics of Galaxies · Physics 2021-12-08 Serena Falocco , Francisco J. Carrera , Josefin Larsson

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

We present the discovery of a high redshift, X-ray selected AGN by the Calan-Yale Deep Extragalactic Research (CYDER) survey: CXOCY J033716.7-050153, located at $z=4.61$, the second high redshift AGN discovered by this survey. Here, we…

We present results exploring the role that probabilistic deep learning models can play in cosmology from large scale astronomical surveys through estimating the distances to galaxies (redshifts) from photometry. Due to the massive scale of…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-16 Evan Jones , Tuan Do , Bernie Boscoe , Yujie Wan , Zooey Nguyen , Jack Singal

Context: Redshifts are fundamental for our understanding of extragalactic X-ray sources. Ambiguous counterpart associations, expensive optical spectroscopy and/or multimission multiwavelength coverage to resolve degeneracies make estimation…

Instrumentation and Methods for Astrophysics · Physics 2018-10-17 Charlotte Simmonds , Johannes Buchner , Mara Salvato , Li-Ting Hsu , Franz Erik Bauer

Despite the plethora of deep (sub-mJy) radio surveys there remains considerable doubt as to the exact nature of the galaxies contributing to the source counts. Current evidence suggests that starformation in moderately luminous 'normal'…

Astrophysics · Physics 2009-11-11 Nick Seymour , Derek Moss , Ian McHardy , Katherine Gunn , Mat Page , Nic Loaring , Tom Dwelly

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

This paper describes an efficient rule generation algorithm, called rule generation from artificial neural networks (RGANN) to generate symbolic rules from ANNs. Classification rules are sought in many areas from automatic knowledge…

Neural and Evolutionary Computing · Computer Science 2010-09-28 S. M. Kamruzzaman

We briefly review some recent results from Chandra and XMM-Newton studies of the highest redshift (z > 4) active galactic nuclei (AGNs). Specific topics covered include radio-quiet quasars, radio-loud quasars, moderate-luminosity AGNs in…

Astrophysics · Physics 2009-11-10 W. N. Brandt , C. Vignali , B. D. Lehmer , L. A. Lopez , D. P. Schneider , I. V. Strateva

We present a machine-learning framework to accurately characterize morphologies of Active Galactic Nucleus (AGN) host galaxies within $z<1$. We first use PSFGAN to decouple host galaxy light from the central point source, then we invoke the…

Direct observations of the first generation of luminous objects will likely become feasible over the next decade. The advent of the Next Generation Space Telescope (NGST) will allow imaging of numerous galaxies and mini-quasars at redshifts…

Astrophysics · Physics 2009-10-31 Rennan Barkana , Abraham Loeb

We briefly review how X-ray observations of high-redshift active galactic nuclei (AGNs) at z = 4-7 have played a critical role in understanding their basic demographics as well as their physical processes; e.g., absorption by nuclear…

High Energy Astrophysical Phenomena · Physics 2017-05-10 W. N. Brandt , F. Vito

We present the identification and analysis of an unbiased sample of AGN that lie within the local galaxy population. Using the MPA-JHU catalogue (based on SDSS DR8) and 3XMM DR7 we define a parent sample of 25,949 local galaxies ($z \leq…

Astrophysics of Galaxies · Physics 2021-12-15 Keir L. Birchall , M. G. Watson , J. Aird , R. L. C. Starling

This study characterises the radio luminosity functions (RLFs) for SFGs and AGN using statistical redshift estimation in the absence of comprehensive spectroscopic data. Sensitive radio surveys over large areas detect many sources with…

We construct a sample of 3,516 radio-loud host galaxies of active galactic nuclei (AGN) from the optical Sloan Digital Sky Survey (SDSS) and Faint Images of the Radio Sky at Twenty cm (FIRST). These have 1.4 GHz luminosities in the range…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-17 Elizabeth J. A. Mannering , Diana M. Worrall , Mark Birkinshaw

I review recent results of the high-redshift X-ray selected AGN clustering, based on the XMM/2dF survey. Using the luminosity-dependent density evolution luminosity function we find that the spatial clustering lengths, derived using…

Astrophysics · Physics 2007-05-23 Manolis Plionis