Related papers: A sub-kpc-scale binary AGN with double narrow-line…

We have analyzed the emission line properties of 6019 Type II AGN at redshifts between 0.4-0.8 with [OIII] luminosities greater than 3x10^8 Lsun, characteristic of the Type II quasars first identified in population studies by Zakamska et al…

Aims: We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN), of all degrees of activity, in the wavelength interval of 0.8-2.4 microns, including the fluxes of the observed emission lines. We analyze the spectroscopic…

The sources SDSS\,J113126.08-020459.2 and SDSS\,J110851.04+065901.4 are two double-peaked [O III] emitting AGN, identified as candidate binary AGNs by optical and near infrared (NIR) observations. We observed the two sources with high…

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…

We present a detailed analysis of the Astrophysical Research Consortium 3.5 m telescope spectrum of QSO SDSS J0838+2955. The object shows three broad absorption line (BAL) systems at 22,000, 13,000, and 4900 km s^-1 blueshifted from the…

According to hierarchical structure formation models, merging galaxies are expected to be seen in different stages of their coalescence. However, currently there are no straightforward observational methods neither to select nor to confirm…

We report the detection of an intriguing parsec-scale radio source in the "offset AGN" candidate, KISSR 102. The elliptical host galaxy includes two optical nuclei at a projected separation of 1.54 kpc, N1 and N2, to the south-east and…

The search and study of close pairs of supermassive black holes (SMBHs) is important in the study of galaxy mergers which can possibly trigger active galactic nucleus (AGN) activity, and in the context of their evolution into the…

We present a sample of 18 optically-selected and X-ray detected spatially offset active galactic nuclei (AGN) from the Sloan Digital Sky Survey (SDSS). In 9 systems, the X-ray AGN is spatially offset from the galactic stellar core that is…

We report the results of an investigation to determine the nature of the offset active galactic nucleus (AGN) found in the source CXO J101527.2+625911. Hubble Space Telescope and Chandra X-ray observatory data had suggested that the offset…

Binary or dual active galactic nuclei (DAGN) are expected from galaxy formation theories. However, confirmed DAGN are rare and finding these systems has proved to be challenging. Recent systematic searches for DAGN using double-peaked…

The X-ray source CXOXBJ142607.6+353351 (CXOJ1426+35), which was identified in a 172 ks Chandra image in the Bootes field, shows double-peaked rest-frame optical/UV emission lines, separated by 0.69" (5.5 kpc) in the spatial dimension and by…

Hierarchical galaxy mergers will lead to the formation of binary and, in the case of a subsequent merger before a binary coalesce, triple supermassive black holes (SMBHs), given that most massive galaxies harbor SMBHs. A triple of SMBHs…

We present an investigation of the structure of the emission line region in a sample of 12 single-peaked Active Galactic Nuclei (AGNs). Using the high resolution H-beta and H-alpha line profiles observed with the Isaac Newton Telescope (La…

We present analysis of the first Chandra observation of PSO J334.2028+01.4075 (PSO J334), targeted as a binary-AGN candidate based on periodic variations of the optical flux. With no prior targeted X-ray coverage for PSO J334, our new 40…

We report a triple black hole candidate with a close binary black hole (BBH) in the blue quasar SDSS J153231.80+420342.7 (=SDSS J1532) at a redshift of 0.209. It shows double-peaked profiles in all narrow emission lines, which can be a…

We present 3-5 micron spectroscopy of the interacting system NGC 6240, showing the presence of two active galactic nuclei. The brightest (southern) nucleus shows up with a starburst-like emission, with a prominent 3.3 micron emission…

We present HST and UKIRT spectra and images of the 2 kpc binary quasar LBQS 0103-2753 (z=0.858). The HST images (V- and I-band) show tidal features demonstrating that this system is a major galaxy merger in progress. A two-color composite…

We present the results of our ALMA Cycle 2 high angular resolution (0.1-0.2 arcsec) observations of the nuclear region of the nearby well-studied type-2 active galactic nucleus (AGN), NGC 1068, at HCN J=3-2 and HCO+ J=3-2 emission lines.…

Driven by the imminent need to rapidly process and classify millions of AGN spectra drawn from next generation astronomical facilities, we present a spectral fitting routine for Type 2 AGN spectra optimised for high volume processing, using…