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Related papers: Revisiting Stochastic Variability of AGNs with Str…

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We study the optical variability characteristics of Active Galactic Nuclei (AGN) from the Swift Burst Alert Telescope (BAT) AGN catalogue by utilising approximately five years of optical light curves from the Zwicky Transient Facility (ZTF)…

High Energy Astrophysical Phenomena · Physics 2025-08-12 Vivek Kumar Jha , Debbijoy Bhattacharya , Hum Chand

This is the first paper in a dedicated series to study the properties of the optically selected BLR-less AGNs (Active Galactic Nuclei with no-hidden central broad emission line regions). We carried out a systematic search for the BLR-less…

Astrophysics of Galaxies · Physics 2015-06-17 Xue Guang Zhang

We systematically analyze X-ray variability of active galactic nuclei (AGNs) in the 7~Ms \textit{Chandra} Deep Field-South survey. On the longest timescale ($\approx~17$ years), we find only weak (if any) dependence of X-ray variability…

We present damped harmonic oscillator (DHO) light-curve modeling for a sample of 12,714 spectroscopically confirmed quasars in the Sloan Digital Sky Survey Stripe 82 region. DHO is a second-order continuous-time autoregressive…

Astrophysics of Galaxies · Physics 2022-09-14 Weixiang Yu , Gordon T. Richards , Michael S. Vogeley , Jackeline Moreno , Matthew J. Graham

We investigate the relation between AGN and star formation (SF) activity at $0.5 < z < 3$ by analyzing 898 galaxies with X-ray luminous AGN ($L_X > 10^{44}$ erg s$^{-1}$) and a large comparison sample of $\sim 320,000$ galaxies without…

We present the star formation rate (SFR) measurements based on the spectral energy distribution (SED) analysis with new sub-mm fluxes combined with archival multi-wavelength data for a sample of 52 AGN host galaxies at z $<0.2$. We carried…

Machine learning is a promising tool to reconstruct time-series phenomena, such as variability of active galactic nuclei (AGN), from sparsely-sampled data. Here we use three Continuous Auto-Regressive Moving Average (CARMA) representations…

High Energy Astrophysical Phenomena · Physics 2022-04-21 Xinyue Sheng , Nicholas Ross , Matt Nicholl

A common feature of Active Galactic Nuclei (AGN) is their random variations in brightness across the whole emission spectrum, from radio to $\gamma$-rays. Studying the nature and origin of these fluctuations is critical to characterising…

Astrophysics of Galaxies · Physics 2025-10-17 Mehdy Lefkir , Simon Vaughan , Daniela Huppenkothen , Phil Uttley , Vysakh Anilkumar

The Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) program monitors 849 active galactic nuclei (AGN) both spectroscopically and photometrically. The photometric observations used in this work span over four years and provide an…

Scaling relations are the most powerful astrophysical tools to set constraints to the physical mechanisms of astro- nomical sources and to infer properties that cannot be accessed directly. We re-investigate here one of these scaling…

Astrophysics of Galaxies · Physics 2018-05-02 O. González-Martín

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 introduce our project, AGNSTRONG (Active Galactic Nuclei and STaR fOrmation in Nearby Galaxies). Our research goals encompass investigating the kinematic properties of ionized and molecular gas outflows, understanding the impact of AGN…

Astrophysics of Galaxies · Physics 2024-05-16 Huynh Anh N. Le , Chen Qin , Yongquan Xue , Shifu Zhu , Kim Ngan N. Nguyen , Ruisong Xia , Xiaozhi Lin

We present the results from the spectral analysis of more than 7,500 RXTE spectra of 10 AGN, which have been observed by RXTE regularly over a long period of time ~ 7-11 years. These observations most probably sample most of the flux and…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-02 M. A. Sobolewska , I. E. Papadakis

We present the two--point correlation function (2PCF) of narrow-line active galactic nuclei (AGN) selected within the First Data Release of the Sloan Digital Sky Survey. Using a sample of 13605 AGN in the redshift range 0.055 < z < 0.2, we…

We study the X-ray variability properties of distant AGNs in the Chandra Deep Field-South region over 17 years, up to $z\sim 4$, and compare them with those predicted by models based on local samples. We use the results of Monte Carlo…

We investigate the effect of active galactic nucleus (AGN) variability on the observed connection between star formation and black hole accretion in extragalactic surveys. Recent studies have reported relatively weak correlations between…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Ryan C. Hickox , James R. Mullaney , David M. Alexander , Chien-Ting J. Chen , Francesca M. Civano , Andy D. Goulding , Kevin N. Hainline

We report the relationship between the luminosities of active galactic nuclei (AGNs) and the rates of star formation (SF) for a sample of 323 far-infrared (FIR)-detected AGNs. This sample has a redshift range of 0.2 $< z <$ 2.5, and spans…

We study a combined sample of 264 star-forming, 51 composite, and 73 active galaxies using optical spectra from SDSS and mid-infrared (mid-IR) spectra from the Spitzer Infrared Spectrograph. We examine optical and mid-IR spectroscopic…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Stephanie M. LaMassa , T. M. Heckman , A. Ptak , D. Schiminovich , M. O'Dowd , B. Bertincourt

Changing-look active galactic nuclei (CL AGNs) show large changes in luminosity and optical spectral state on time-scales of a few years, and provide a valuable probe of time-dependent accretion in the disc-BLR-torus system. We present a…

Astrophysics of Galaxies · Physics 2026-03-19 Yu Tao , Jie Tang , Xuan Wei