Related papers: A candidate sub-parsec binary black hole in the Se…
A new radio map of the Abell 85 Brightest Cluster Galaxy (BCG) was obtained with the Karl G. Jansky Very Large Array (VLA). With a resolution of 0.02", this radio image shows two kiloparsec-scale bipolar jets emanating from the active…
Supermassive black holes (SMBHs) of 10^9-10^10 Msun were already in place ~13 Gyr ago, at z>6. Super-Eddington growth of low-mass BH seeds (~100 Msun) or less extreme accretion onto ~10^5 Msun seeds have been recently considered as the main…
Analyzing single-dish and VLBI radio, as well as \textit{Fermi}-LAT $\gamma$-ray observations, we explained the three major flares in the $\gamma$-ray light curve of FSRQ J1048+7143 with the spin--orbit precession of the dominant mass black…
The most massive black holes in our Universe form binaries at the centre of merging galaxies. The recent evidence for a gravitational-wave (GW) background from pulsar timing may constitute the first observation that these supermassive black…
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…
In this work, we report a radio galaxy with precessing jets, double-peaked emission lines and the presence of two compact radio components with a projected separation of ~6 parsec in Very Long Baseline Interferometry (VLBI) observations.…
Supermassive black holes are commonly found in the center of galaxies and evolve with their hosts. The supermassive binary black holes (SMBBH) are thus expected to exist in close galaxy pairs, however, none has been unequivocally detected.…
Wandering massive black holes (MBHs) are thought to form through gravitational recoil or galaxy mergers, but observational confirmation of their displacement in dwarf galaxies, critical laboratories for early-universe SMBH seeding, remains…
During a galaxy merger, the supermassive black hole (SMBH) in each galaxy is thought to sink to the center of the potential and form a supermassive black hole binary; this binary can eject stars via 3-body scattering, bringing the SMBHs…
The combined University of Michigan Radio Astronomy Observatory (UMRAO) and Owens Valley Radio Observatory (OVRO) blazar monitoring programs at 14.5/15 GHz provide uninterrupted light curves of $\sim~46-50$ yr duration for 83 blazars,…
Double-peaked broad emission lines in Active Galactic Nuclei (AGNs) may indicate the existence of a bound supermassive black hole (SMBH) binary where two distinct broad line regions (BLRs) contribute together to the line profile. An…
During a systematic search for supermassive black holes (SMBHs) not in galactic nuclei, we identified the compact symmetric radio source B3 1715+425 with an emission-line galaxy offset ~ 8.5 kpc from the nucleus of the brightest cluster…
Supermassive black hole (SMBH) binaries form due to galaxy mergers and minor accretion events. When the SMBHs are accreting, they form dual or binary AGN and can give rise to double-peaked emission lines in the optical spectra of the merger…
We present HST WFPC2/PC images and KPNO 4-m longslit spectroscopy of the QSO SDSS J153636.22+044127.0, which we advanced as a candidate binary supermassive black hole. The images reveal a close companion coincident with the radio source…
We present results from multi-frequency polarization-sensitive Very Large Array observations of the Seyfert-starburst composite galaxy NGC3079. Our sensitive radio observations reveal a plethora of radio filaments comprising the radio lobes…
Synergies between the {\em James Webb Space Telescope} ({\em JWST}) and the {\em Chandra} X-ray observatory have advanced the observational frontier by detecting a handful of active galactic nuclei (AGNs) beyond $z \sim$ 10. In particular,…
Recently, Rakshit et al. (2018) reported the discovery of SDSS J103024.95$+$551622.7, a radio-loud narrow-line Seyfert 1 galaxy having a $\sim 100$ kpc scale double-lobed radio structure. Here we analyse archival radio interferometric…
We present the serendipitous discovery of a double-double radio galaxy (DDRG) with a projected linear size exceeding 2 Mpc, hosted by a spiral galaxy. This unique combination of a giant radio structure and a spiral host challenges the…
Stellar black hole (BH) binaries are one of the most promising gravitational wave (GW) sources for GW detection by the ground-based detectors. Nuclear star clusters (NCs) located at the centre of galaxies are known to harbour massive black…
Although thousands of galaxy mergers are known, only a handful of sub-kiloparsec-scale supermassive black hole (SMBH) pairs have been confirmed so far, leaving a huge gap between the observed and predicted numbers of such objects. In this…