Related papers: The Most Massive Active Galactic Nuclei at $1\less…

Reverberation mapping (RM) of active galactic nuclei (AGNs) has been used over the past three decades to determine AGN broad-line region (BLR) sizes and central black-hole masses, and their relations with the AGN's luminosity. Until…

Kpc-scale triple active galactic nuclei (AGNs), potential precursors of gravitationally-bound triple massive black holes (MBHs), are rarely seen objects and believed to play an important role in the evolution of MBHs and their host…

In the last decade, there have been several discoveries of Active Galactic Nuclei (AGN) in dwarf galaxies including an AGN in an ultra-compact dwarf galaxy with a Black Hole mass $>$10$^{6}$ M$_{\odot}$. However, finding a Supermassive…

High-$z$ AGNs hosted in gas rich galaxies are expected to grow through significantly obscured accretion phases. This may limit or bias their observability. In this work, we use \textsc{BlueTides}, a large volume cosmological simulation of…

We present a comprehensive analysis of the X-ray spectral properties of 198 newly identified active galactic nuclei (AGNs), leveraging archival data from the {\it Chandra} X-ray Observatory. All these AGNs exhibit a powerlaw spectral…

We present results of the clustering analysis between active galactic nuclei (AGNs) and galaxies at redshift 0.1-1.0 for investigating properties of galaxies associated with the AGNs, revealing the nature of fueling mechanism of…

Although the super-massive (AGN) and stellar mass (XRBs) black holes have many properties in common, the broad emission lines (BELs) are exclusively signatures of the AGN. Based on the detection of these lines from SDSS data bases, there…

We present a sample of 131 quasars from the Sloan Digital Sky Survey at redshifts 0.8<z<1.6 with double peaks in either of the high-ionization narrow emission lines [NeV]3426 or [NeIII]3869. These sources were selected with the intention of…

Double-peaked narrow emission lines in active galactic nucleus (AGN) spectra can be produced by AGN outflows, rotation, or dual AGNs, which are AGN pairs in ongoing galaxy mergers. Consequently, double-peaked narrow AGN emission lines are…

From a parent catalog of 561 changing-look active galactic nuclei (CL-AGNs) identified by Guo et al. (2025), we investigate the evolutionary sequence of broad emission lines using a redshift-selected subset (0.35 < z < 0.45) of 54 CL-AGNs…

In this work, we aim to further populate the low-mass regime of black hole (BH) scaling relations to better understand the formation and growth mechanisms of central supermassive BHs. We target six galaxies that have been previously…

Broad (~10,000 km/s), double-peaked emission-line profiles of Balmer lines emitted by active galactic nuclei (AGN) are thought to originate in the outer parts of an accretion disk surrounding a nuclear supermassive black hole (SMBH), at…

In contrast to massive galaxies with Solar or super-Solar gas phase metallicities, very few Active Galactic Nuclei (AGN) are found in low-metallicity dwarf galaxies. Such a population could provide insight into the origins of supermassive…

Type 2 active galactic nuclei (AGN) represent the majority of the AGN population. However, due to the difficulties in measuring their black hole (BH) masses, it is still unknown whether they follow the same BH mass-host galaxy scaling…

We take advantage of the rich multi-wavelength data available in the Chandra Deep Field South (CDF-S), including the 4 Msec Chandra observations (the deepest X-ray data to date), in order to search for heavily-obscured low-luminosity AGN…

We have obtained new spectropolarimetric observations at visible wavelengths of the changing-look active galactic nucleus (AGN) Mrk 1018. The AGN direct spectrum shows an extremely weak continuum with faint broad H$\beta$ and H$\alpha$…

Distant quasars (QSOs) in galaxy overdensities are considered key actors in the evolution of the early Universe. In this work, we studied the kinematic and physical properties of the BR1202-0725 system at z=4.7, one of the most overdense…

We present X-ray and multiwavelength studies of a sample of eight high-luminosity active galactic nuclei (AGNs) with disc-like H\beta emission-line profiles selected from the Sloan Digital Sky Survey Data Release 7. These sources have…

Massive black holes (BHs) in dwarf galaxies can provide strong constraints on BH seeds, however reliably detecting them is notoriously difficult. High resolution radio observations were recently used to identify accreting massive BHs in…

To understand the origin of nuclear ($\lesssim$ 100 pc) millimeter-wave (mm-wave) continuum emission in active galactic nuclei (AGNs), we systematically analyzed sub-arcsec resolution Band-6 (211-275 GHz) ALMA data of 98 nearby AGNs ($z <$…