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Related papers: Navigating AGN variability with self-organizing ma…

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We use mid-infrared variability in galaxies to search for active galactic nuclei (AGN) in the local universe. We use a sample of 10,220 galaxies from the Mapping Nearby Galaxies at APO (MaNGA) survey, part of the Sloan Digital Sky Survey…

Astrophysics of Galaxies · Physics 2024-12-09 Aashay Pai , Michael R. Blanton , John Moustakas

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…

Astrophysics of Galaxies · Physics 2021-10-26 Yu-Yen Chang , Bau-Ching Hsieh , Wei-Hao Wang , Yen-Ting Lin , Chen-Fatt Lim , Yoshiki Toba , Yuxing Zhong , Siou-Yu Chang

Classifying catalog objects as stars, galaxies, or AGN is a crucial part of any statistical study of galaxies. We describe our pipeline for binary (star/galaxy) and multiclass (star/galaxy/Type I AGN/Type II AGN) classification developed…

Astrophysics of Galaxies · Physics 2021-04-14 Anneya Golob , Marcin Sawicki , Andy D. Goulding , Jean Coupon

The morphological study is crucial to investigate the connections between active galactic nuclei (AGN) activities and the evolution of galaxies. Substantial studies have found that radiative-mode AGNs primarily reside in disk galaxies,…

Astrophysics of Galaxies · Physics 2022-02-09 Yuxing Zhong , Akio K. Inoue , Satoshi Yamanaka , Toru Yamada

The fast classification of new variable stars is an important step in making them available for further research. Selection of science targets from large databases is much more efficient if they have been classified first. Defining the…

Astrophysics · Physics 2009-11-13 J. Debosscher , L. M. Sarro , C. Aerts , J. Cuypers , B. Vandenbussche , R. Garrido , E. Solano

In a series of papers based on the FIRST and Sloan Digital Sky Surveys (SDSS), we investigate the local population of star-forming galaxies and Active Galactic Nuclei (AGN) in order to clarify the link between these two types of activity,…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-25 Pietro M. Reviglio , David J. Helfand

Literature on optical and infrared microvariability in Active Galactic Nuclei (AGNs) reflects a diversity of statistical tests and strategies to detect tiny variations in the lightcurves of these sources. Comparison between the results…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Jose A. de Diego

The field of gamma ray astronomy relies heavily on the statistical analysis of data. Because of the paucity of data, and the often large errors associated with detecting gamma rays, analysis and interpretation of the data require…

Astrophysics · Physics 2007-05-23 W. F. Tompkins

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…

Astrophysics of Galaxies · Physics 2022-12-16 Ziting Guo , John F. Wu , Chelsea E. Sharon

We analyze the X-ray properties for a sample of 23 high probability AGN candidates with ultraviolet variability identified in Wasleske et al. (2022). Using data from the Chandra X-ray Observatory and the XMM-Newton Observatory, we find…

Astrophysics of Galaxies · Physics 2024-05-31 Erik J. Wasleske , Vivienne F. Baldassare

We use HST/ACS images and a photometric catalog of the COSMOS field to analyze morphologies of the host galaxies of approximately 400 AGN candidates at redshifts 0.3 < z < 1.0. We compare the AGN hosts with a sample of non-active galaxies…

We present the results of a program to identify so far unknown active nuclei (AGN) in galaxies. Candidate galactic nuclei have been selected for optical spectroscopy from a cross-correlation of the ROSAT all sky survey (RASS) bright source…

Astrophysics · Physics 2007-05-23 K. Bischoff , W. Pietsch , T. Boller , S. Döbereiner , W. Kollatschny , H. -U. Zimmermann

Obtaining a census of active galactic nuclei (AGN) activity across cosmic time is critical to our understanding of galaxy evolution and formation. Many AGN classification techniques are compromised by dust obscuration. However, very long…

Astrophysics of Galaxies · Physics 2021-05-12 J. F. Radcliffe , P. D. Barthel , A. P. Thomson , M. A. Garrett , R. J. Beswick , T. W. B. Muxlow

The unified model of active galactic nuclei (AGN) includes a toroidal obscuring structure to explain the differences between Type I and Type II AGN as an effect of inclination angle. This toroidal structure is thought to be 'clumpy' as the…

Astrophysics of Galaxies · Physics 2023-01-19 Isaiah Cox , Nuria Torres-Alba , Stefano Marchesi , Xiurui Zhao , Marco Ajello , Andrealuna Pizzetti , Ross Silver

We present a numerical framework for the variability of active galactic nuclei (AGN), which links the variability of AGN over a broad range of timescales and luminosities to the observed properties of the AGN population as a whole, and…

Astrophysics of Galaxies · Physics 2019-10-09 Lia F. Sartori , Benny Trakhtenbrot , Kevin Schawinski , Neven Caplar , Ezequiel Treister , Ce Zhang

{We focus on characterizing the high-energy emission mechanisms of blazars by analyzing the variability in the radio band of the light curves of more than a thousand sources. We are interested in assigning complexity parameters to these…

Data Analysis, Statistics and Probability · Physics 2022-05-11 Belén Acosta-Tripailao , Walter Max-Moerbeck , Denisse Pastén , Pablo S. Moya

We study the black hole mass $-$ host galaxy stellar mass relation, $M_{\rm{BH}}-M_{\ast}$, for a sample of 706 $z \lesssim 1.5$ and $i \lesssim 24$ optically-variable active galactic nuclei (AGNs) in three Dark Energy Survey (DES) deep…

Astrophysics of Galaxies · Physics 2025-03-11 Yichen Liu , Colin J. Burke , Diego Miura , Xin Liu , Qian Yang , Priyamvada Natarajan , Charlotte A. Ward

The goal of this work is to search for Active Galactic Nuclei (AGN) in the Galactic disc at very low latitudes with |b| $<$ 2$^\circ$. For this, we studied the five sources from the VVV near-infrared galaxy catalogue that have also WISE…

The variability of active galactic nuclei (AGNs) is ubiquitous but has not yet been understood. Measuring the optical variation properties of AGNs, such as variation timescale and amplitude, and then correlating them with their fundamental…

Astrophysics of Galaxies · Physics 2024-01-11 Xu-Fan Hu , Zhen-Yi Cai , Jun-Xian Wang
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