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We present results of recurrence analysis of 46 active galactic nuclei (AGN) using light curves from the 157-month catalog of the Swift Burst Alert Telescope (BAT) in the 14-150 keV band. We generate recurrence plots and compute recurrence…

High Energy Astrophysical Phenomena · Physics 2022-11-28 R. A. Phillipson , M. S. Vogeley , P. T. Boyd

We study the distribution of Eddington luminosity ratios, L_bol/L_edd, of active galactic nuclei (AGNs) discovered in the AGN and Galaxy Evolution Survey (AGES). We combine H-beta, MgII, and CIV line widths with continuum luminosities to…

The masses of 68 supermassive black holes (SMBHs) in nearby (z<0.15) active galactic nuclei (AGNs) detected by the INTEGRAL observatory in the hard X-ray energy band (17-60 keV) outside the Galactic plane (|b| > 5 degrees) have been…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-24 G. A. Khorunzhev , S. Yu. Sazonov , R. A. Burenin , A. Yu. Tkachenko

The large-scale environments of active galactic nuclei (AGN) reveal important information on the growth and evolution of supermassive black holes (SMBHs). Previous AGN clustering measurements using 2-point correlation functions have hinted…

Astrophysics of Galaxies · Physics 2025-09-03 A. Mhatre , M. C. Powell , S. Yuan , S. W. Allen , T. Caglar , M. Koss , I. del Moral-Castro , K. Oh , A. Peca , C. Ricci , F. Ricci , A. Rojas , M. Signorini

We have newly identified a substantial number of type 1 active galactic nuclei (AGN) featuring weak broad-line regions (BLRs) at z < 0.2 from detailed analysis of galaxy spectra in the Sloan Digital Sky Survey Data Release 7. These objects…

Astrophysics of Galaxies · Physics 2015-07-15 Kyuseok Oh , Sukyoung K. Yi , Kevin Schawinski , Michael Koss , Benny Trakhtenbrot

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 active galactic nuclei X-ray luminosity function traces actively accreting supermassive black holes and is essential for the study of the properties of the active galactic nuclei (AGN) population, black hole evolution, and galaxy-black…

A supermassive black hole (SMBH) ejected from the potential well of its host galaxy via gravitational wave recoil carries important information about the mass ratio and spin alignment of the pre-merger SMBH binary. Such a recoiling SMBH may…

With the advancement of technology, machine learning-based analytical methods have pervaded nearly every discipline in modern studies. Particularly, a number of methods have been employed to estimate the redshift of gamma-ray loud active…

High Energy Astrophysical Phenomena · Physics 2023-12-13 Sarvesh Gharat , Abhimanyu Borthakur , Gopal Bhatta

More than 50% of Active Galactic Nuclei (AGNs) are suspected to be red and affected by dust-obscuration. Meanwhile, popular spectral diagnostics of AGNs are based on optical or ultraviolet light, making the dust obscuration as a primary…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Dohyeong Kim , Myungshin Im , Minjin Kim

Understanding the relationship between supermassive black holes (SMBHs) and their host galaxies at different redshifts is crucial for unraveling the processes of SMBH-galaxy co-evolution. We present the properties of nine type 1 Active…

Astrophysics of Galaxies · Physics 2025-07-03 Atsushi Hoshi , Toru Yamada

X-rays provide a robust method in identifying AGN. However, in the high-redshift Universe, their space density is relatively low, and, in combination with the small areas covered by X-ray surveys, the selected AGN are poorly sampled. Deep…

Astrophysics of Galaxies · Physics 2025-05-21 E. Pouliasis , A. Ruiz , I. Georgantopoulos , A. Akylas , N. A. Webb , F. J. Carrera , S. Mateos , A. Nebot , M. G. Watson , F. X. Pineau , C. Motch

We present a sample of 930 intermediate-mass black hole (IMBH) active galactic nuclei (AGNs) with black hole masses of $M_\mathrm{BH} \leqslant 2 \times 10^{6}$ M$_{\odot}$, uniformly selected from the Seventeenth Data Release of the Sloan…

Astrophysics of Galaxies · Physics 2026-05-12 Wen-Juan Liu , Luis C. Ho , Xiao-Bo Dong , Su Yao , Paulina Lira , Yicheng Guo

In order to study the evolution of the relative fraction of obscured Active Galactic Nuclei (AGN) we constructed the largest sample to date of AGN selected in hard X-rays. The full sample contains 2341 X-ray-selected AGN, roughly 4 times…

Astrophysics · Physics 2009-11-11 Ezequiel Treister , C. Megan Urry

The co-evolution of host galaxies and the active black holes which reside in their centre is one of the most important topics in modern observational cosmology. Here we present a study of the properties of obscured Active Galactic Nuclei…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 M. Brusa , F. Fiore , P. Santini , A. Grazian , A. Comastri , G. Zamorani , G. Hasinger , A. Merloni , F. Civano , A. Fontana , V. Mainieri

The cosmic history of supermassive black hole (SMBH) growth is important for understanding galaxy evolution, reionization and the physics of accretion. Recent NuSTAR, Swift-BAT and \textit{Chandra} hard X-ray surveys have provided new…

Understanding the co-evolution of supermassive black holes (SMBHs) and their host systems requires a comprehensive census of active galactic nuclei (AGN) behavior across a wide range of redshift, luminosity, obscuration level and galaxy…

Measuring the redshift of active galactic nuclei (AGNs) requires the use of time-consuming and expensive spectroscopic analysis. However, obtaining redshift measurements of AGNs is crucial as it can enable AGN population studies, provide…

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 present our statistical analysis of the connection between active galactic nuclei (AGN) variability and physical properties of the central supermassive black hole (SMBH). We constructed optical light curves using data from the QUEST-La…

Astrophysics of Galaxies · Physics 2018-09-19 P. Sánchez-Sáez , P. Lira , J. Mejía-Restrepo , L. C. Ho , P. Arévalo , M. Kim , R. Cartier , P. Coppi