Related papers: Constraining VLBI-optical offsets in high redshift…

Low-luminosity radio-loud active galactic nuclei (AGN) are of importance in studies concerning feedback from radio AGN since a dominant fraction of AGN belong to this class. We report high-resolution Very Large Array (VLA) and European VLBI…

Following our study of the radio and high-energy properties of $\gamma$-ray-emitting radio galaxies, here we investigate the kinematic and spectral properties of the parsec-scale jets of radio galaxies that have not yet been detected by…

We report on the discovery of three bright, strongly-lensed objects behind Abell 1703 and CL0024+16 from a dropout search over 25 square arcminutes of deep NICMOS data, with deep ACS optical coverage. They are undetected in the deep ACS…

We use high-resolution adaptive optics (AO) imaging on the Keck II telescope to study the gravitational lens B0128+437 in unprecedented detail, allowing us to resolve individual lensed quasar components and, for the first time, detect and…

We present a novel pilot search for gravitational lenses in the mJIVE-20 survey, which observed $24\,903$ radio sources selected from FIRST with the VLBA at an angular resolution of 5 mas. We have taken the visibility data for an initial…

We search for strongly lensed and multiply imaged gravitational wave signals in the second observing run of Advanced LIGO and Advanced Virgo (O2). We exploit a new source of information, the so-called Morse phase, which further mitigates…

We cross-identified the ROSAT Bright Source Catalog (RBSC) and the NRAO VLA Sky Survey (NVSS) to construct the RBSC-NVSS sample of the brightest X-ray sources (>= 0.1 counts/s or ~1E-12 ergs/cm/cm/s in the 0.1-2.4 keV band) that are also…

We present phase-referenced VLBI results on the radio continuum and the OH 18 cm megamaser emission from the Ultra-Luminous Infrared Galaxy, IRAS 17208--0014. The observations were carried out at 1599 MHz using the Very Long Baseline Array,…

We present HST observations of previously undetected optical jets in the low-luminosity radio galaxies B2 0755+37 and B2 1553+24. We show that there is accurate spatial coincidence between optical and radio emission, implying that the…

We present a joint analysis of rest-UV and rest-optical spectra obtained using Keck/LRIS and Keck/MOSFIRE for a sample of 62 star-forming galaxies at $z\sim2.3$. We divide our sample into 2 bins based on their location in the [OIII]/Hb vs.…

We use a Chandra X-ray observation of the gravitationally lensed system MGB2016+112 at z=3.273 to elucidate presence of at least two X-ray sources. We find that these sources are consistent with the VLBI components measured by…

Radio-loud quasars at high redshift (z > 4) are rare objects in the Universe and rarely observed with Very Long Baseline Interferometry (VLBI). But some of them have flux density sufficiently high for monitoring of their apparent position.…

We present a series of high resolution radio and optical observations of the CLASS gravitational lens system B1152+199 obtained with the Multi-Element Radio-Linked Interferometer Network (MERLIN), Very Long Baseline Array (VLBA) and Hubble…

Robotic telescope networks play an important role in capturing early and bright optical afterglows, providing critical insights into the energetics and emission mechanisms of GRBs. In this study, we analyze GRB 230204B, an exceptionally…

We have made radio- and millimeter-wavelength interferometric observations of a variety of molecular absorption lines toward the gravitational lens systems B0218+357 and PKS1830-211. The absorption occurs in the lensing galaxies at…

Compact symmetric objects (CSOs) are thought to be short-lived radio sources with two lobes of emission that are separated by less than a kpc in projection. However, studies of such systems at high redshift is challenging due to the limited…

Central gravitational image detection is very important for the study of the mass distribution of the inner parts ($\sim 100$ pc) of lens galaxies. However, the detection of such images is extremely rare and difficult. We present a 1.7-GHz…

As part of a program to study the relationship between QSO Lyman alpha clouds and galaxies at low redshifts, we have obtained a high signal-to-noise far UV spectrum of H 1821+643 [z(em) = 0.297] with the G140L grating of the GHRS. The…

Recent observations show a population of active galaxies with milliarcseconds offsets between optical and radio emission. Such offsets can be an indication of extreme phenomena associated with supermassive black holes including relativistic…

We present very long baseline interferometry (VLBI) images of ten very high redshift (z>3) quasars at 5 GHz. The sources 0004+139, 0830+101, 0906+041, 0938+119 and 1500+045 were observed in September 1992 using a global VLBI array, while…