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Strong both broad and narrow emission lines from central broad emission line regions (BLRs) and narrow emission line regions (NLRs) are fundamental spectroscopic characteristics of broad line Active Galactic Nuclei (BLAGNs). Lack of central…

Astrophysics of Galaxies · Physics 2025-06-24 Zhang XueGuang

In the manuscript, the composite galaxy SDSS J103911-000057 (=SDSS J1039) is reported as a better candidate of true Type-2 AGN without hidden BLRs. None broad but only narrow emission lines detected in SDSS J1039 can be well confirmed both…

Astrophysics of Galaxies · Physics 2022-03-25 XueGuang Zhang , YingFei Zhang , PeiZhen Cheng , BaoHan Wang , YiLi Lv , HaiChao Yu

In this manuscript, we study properties of BLR of well-known reverberation-mapped AGN, in order to find reliable evidence for intermediate BLR. We firstly check properties of mapped AGN collected from literature in plane of $\sHb^2/\sHa^2$…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-16 Xue-Guang Zhang

In the manuscript, a candidate of sub-pc binary black hole (BBH) system is reported in SDSS J1257+2023 through different properties of broad Balmer emission lines. After subtractions of host galaxy contributions, Gaussian functions are…

Astrophysics of Galaxies · Physics 2023-08-02 XueGuang Zhang

There is clear observational evidence that some narrow line (type 2) AGN have a hidden broad line region (BLR), and are thus intrinsically broad line (type 1) AGN. Does this AGN unification applies for all type 2 AGN? Indirect arguments…

Astrophysics · Physics 2009-11-07 Ari Laor

The profiles of broad emission lines in active galactic nuclei (AGNs) provide critical insights into the geometry and kinematics of the broad-line region (BLR), which in turn influence the uncertainties in estimating the masses of central…

Astrophysics of Galaxies · Physics 2025-06-10 Jiancheng Wu , Qingwen Wu , Chen Hu , Bing Lyu , Hua-Rui Bai , Yi-Xin Fu , Yu Zhao , Jian-Min Wang , Xinwu Cao

We report the virial measurements of the BH mass of a sample of 17 type 2 AGN, drawn from the Swift/BAT 70-month 14-195 keV hard X-ray catalogue, where a faint BLR component has been measured via deep NIR (0.8-2.5 $\mu$m) spectroscopy. We…

Astrophysics of Galaxies · Physics 2017-04-12 F. Onori , F. Ricci , F. La Franca , S. Bianchi , A. Bongiorno , M. Brusa , F. Fiore , R. Maiolino , A. Marconi , E. Sani , C. Vignali

Here we investigate the kinematics of the part of the broad line region (BLR) in active galactic nuclei (AGNs) emitting H$\beta$ and H$\alpha$ emission lines. We explore the widths and asymmetries of the broad H$\beta$ and H$\alpha$…

Astrophysics of Galaxies · Physics 2022-08-24 Nemanja Rakić

We present measurements of broad emission lines and virial estimates of supermassive black hole masses ($M_{BH}$) for a large sample of ultra-hard X-ray selected active galactic nuclei (AGNs) as part of the second data release of the BAT…

According to the classical AGN model, broad emission lines originate from the broad-line region (BLR) and are observable only when the attenuation by the dusty torus is small. However, we recently found several heavily-obscured ($A_V > 50$…

The hidden broad-line regions (BLRs) in Seyfert 2 galaxies, which display broad emission lines (BELs) in their polarized spectra, are a key piece of evidence in support of the unified model for active galactic nuclei (AGNs). However, the…

Astrophysics of Galaxies · Physics 2017-05-03 Pu Du , Jian-Min Wang , Zhi-Xiang Zhang

The line widths of broad line regions (BLRs) of AGNs are key parameters for understanding the central super massive black holes (SMBHs). However, due to obscuration from dusty torus, optical recombination lines from BLRs in type II AGNs can…

Astrophysics of Galaxies · Physics 2022-11-15 Junzhi Wang , Yong Shi , Zhi-Yu Zhang , Shu Liu , Yu Gao , Jiangshui Zhang , Fengyao Zhu , Min Fang

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

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

In the manuscript, the properties of the proposed intermediate BLR are checked for the mapped AGN PG 0052+251. With the considerations of the apparent effects of the broad He {\sc ii} line on the observed broad H$\beta$ profile, the line…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 XueGuang Zhang

In this manuscript, through applications of TDE (tidal disruption event) expected variability properties, a potential candidate for True type-2 AGN without hidden central broad line regions (=TT2AGN) is reported in the SDSS…

Astrophysics of Galaxies · Physics 2025-05-28 Gu Ying , Zheng Qi , Cheng Peizheng , Li Xiao , Xing-Qian Cheng , Zhang XueGuang , Liang EnWei

The main objective is to check the Unified Model (UM) expected similar stellar velocity dispersions between Type-1 AGN and Type-2 AGN, then to provide further clues on BH mass properties. Not similar as previous comparisons of BH masses…

Astrophysics of Galaxies · Physics 2022-05-03 Zhang XueGuang

The SINFONI survey for Unveiling the Physics and Effect of Radiative feedback (SUPER) was designed to conduct a blind search for AGN-driven outflows on X-ray selected AGN at redshift z$\sim$2 with high ($\sim$2 kpc) spatial resolution, and…

We analyze the properties of the broad line region (BLR) in low luminosity AGN by using HST/STIS spectra. We consider a sample of 24 nearby galaxies in which the presence of a BLR has been reported from their Palomar ground-based spectra.…

Astrophysics of Galaxies · Physics 2015-06-18 B. Balmaverde , A. Capetti , INAF - Osservatorio Astrofisico di Torino

Dust torus plays the key role in determining active galactic nuclei (AGN) observational appearance. Here, the scenario of accretion regulated central dust torus is tested for the first time in the individual changing-look AGN (CLAGN) SDSS…

Astrophysics of Galaxies · Physics 2026-04-09 Zhang XueGuang
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