Related papers: The Quasar SDSS J1536+0441: An Unusual Double-Peak…
We report the discovery of two doubly-imaged quasars, SDSS J100128.61+502756.9 and SDSS J120629.65+433217.6, at redshifts of 1.838 and 1.789 and with image separations of 2.86'' and 2.90'', respectively. The objects were selected as lens…
Imaging and spectroscopy with HST show that LBQS 0103-2753 (V = 17.8, z = 0.848) is a binary quasar with a separation of 0.3 arcsec or 2.3 kpc. This is by far the smallest separation binary quasar reported to date. The two components have…
We report the confirmation of a kpc-scale binary active galactic nucleus (AGN) with high-resolution radio images from the Expanded Very Large Array (EVLA). SDSS J150243.1+111557 is a double-peaked [O III] AGN at z = 0.39 selected from the…
New spectroscopic observations of the halo hyper-velocity star candidate SDSS J121150.27+143716.2 ($V=17.92$ mag) revealed a cool companion to the hot subdwarf primary. The components have a very similar radial velocity and their absolute…
Optically bright, wide separation double (gravitationally lensed) quasars can be easily monitored, leading to light curves of great importance in determining the Hubble constant and other cosmological parameters, as well as the structure of…
We discuss results from very long baseline interferometry (VLBI) observations of two Seyfert galaxies with double peaked emission lines in their SDSS optical spectra. Such AGN are potential candidates for the presence of binary black holes,…
The millisecond pulsar in a triple system (PSR J0337+1715, recently discovered by Ransom et al.) is an unusual neutron star with two orbiting white dwarfs. The existence of such a system in the Galactic field poses new challenges to stellar…
Models and observations suggest that luminous quasar activity is triggered by mergers, so it should preferentially occur in the most massive primordial dark matter haloes, where the frequency of mergers is expected to be the highest. Since…
Spectroscopic observations of the quasar J0950$+$5128 spanning 22 years reveal monotonic radial velocity variations in its broad H$\beta$ emission line. Moreover, the line profile becomes broader over time, necessitating careful…
During galaxy merger events, the supermassive black holes in the center of the galaxies may form a pair of active galactic nuclei (AGN) with kpc-scale or even pc-scale separation. Recently, optical observations revealed a promising dual AGN…
Dual quasars separated at kiloparsec scale are widely regarded as precursors to binary supermassive black holes and offer a key insight into the dynamical evolution of galaxy mergers. Our series of studies focus on searching for dual…
Dual/binary Supermassive Black Hole (SMBH) systems are the inevitable consequence of the current Lambda Cold Dark Matter cosmological paradigm. In this context, we discuss here the properties of MCG+11-11-032, a local (z=0.0362) Seyfert 2…
LSI+61303 is one of the most observed Be/X-ray binary systems because, peculiarly, it has periodical radio and X-ray emission together with strong, variable gamma-ray emission. This source remains, however, quite enigmatic. Some properties…
We present results on a multi-wavelength analysis of SDSS J025214.67-002813.7, a system which has been previously classified as a binary AGN candidate based on periodic signals detected in the optical light curves. We use available…
We report our investigation of 1SWASP J234401.81-212229.1, a variable with a 18461.6 s period. After identification in a 2011 search of the SuperWASP archive for main-sequence eclipsing binary candidates near the distribution's short-period…
This manuscript investigates the possible existence of a binary supermassive black holes (BSMBH) system in the blue quasar SDSS J100438.8+151056 (=SDSS J1004+1510) at z=0.219 based on the detection of robust optical QPOs. We determine QPOs…
We present the discovery of strongly variable emission lines from a gaseous disc around the DA white dwarf SDSS J1617+1620, a star previously found to have an infrared excess indicative of a dusty debris disc formed by the tidal disruption…
We have studied the nuclear region of the previously detected dual AGN system in the galaxy pair IRAS 05589+2828 and 2MASX J06021107+2828382 through new optical spectroscopy observations, along with radio and X-ray archival data. Our…
In this manuscript, very blue-shifted broad H$\alpha$ with shifted velocity $\sim$2200km/s is reported in the low redshift Type-1.9 AGN SDSS J1052+1036. Blue-shifted broad emission lines may arise due to the presence of a rotating gas disk…
We have explored the nature of the extended emission-line region around the z=0.37 quasar 4C 37.43, using extensive ground-based and HST imaging and spectroscopy. The velocity field of the ionized gas shows gradual gradients within…