Related papers: The VLBA Calibrator Survey - VCS1

We conducted Very Long Baseline Array (VLBA) observations of seven nearby narrow-line Seyfert 1 (NLS1) galaxies at 1.7 GHz (18cm) with milli-arcsecond resolution. This is the first systematic very long baseline interferometry (VLBI) study…

Space-VLBI observations of stellar sources represent a challenge since there are few sources with sufficiently high brightness temperature for detection on space-ground baselines. X-ray binaries (XRB) are among the few types of stellar…

We present a wide-area and deep optical identification catalog for radio sources based on the VLASS Epoch 2 catalog at 3 GHz. Optical counterparts are identified using the final-year internal processing of the Hyper Suprime-Cam Subaru…

The observation and imaging of hundreds or thousands of radio sources with the technique of very long baseline interferometry (VLBI) is a computationally intensive task. However, these surveys allow us to conduct statistical investigations…

We have used the Very Large Array to search for compact milliarcsecond-size radio sources near methanol masers in high-mass star-forming regions. Such sources are required for Very Long Baseline Interferometry phase-referencing…

The VLA-COSMOS Large Project has imaged the 2 sq.deg. COSMOS field with a resolution of 1.5 arcsec and a sensitivity of about 11 microJy (1 sigma) yielding to a catalog of about 3600 radio sources. In this paper we present a further…

This thesis reports on the application of new wide-field Very Long Baseline Interferometry (VLBI) imaging techniques using real data for the first time. These techniques are used to target three specific science areas: (i) a…

We present the first astrometry catalog from the Japanese VLBI (very long baseline interferometer) project VERA (VLBI Exploration of Radio Astrometry). We have compiled all the astrometry results from VERA, providing accurate trigonometric…

We present the first results from a pilot study to search for distant radio galaxies in the southern hemisphere (delta < -32). Within a 360 deg^2 region of sky, we define a sample of 76 ultra-steep spectrum (USS) radio sources from the 843…

PKS 1155+251 is a radio-loud quasar source at z=0.203. Observations using very long baseline interferometry (VLBI) at ~2, 5, 8 and 15 GHz show that the structure of the radio source is quite complicated on parsec scales and that the outer…

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 preliminary results from a VLBI survey at $\lambda=6 $cm of a sample of 35 sources with flux densities of 2 - 100 mJy. These sources were selected from the VLA FIRST survey at $\lambda = 20 $cm, in a 3 degree field around the…

We report on the first wide-field, very long baseline interferometry (VLBI) survey at 90 cm. The survey area consists of two overlapping 28 deg^2 fields centred on the quasar J0226+3421 and the gravitational lens B0218+357. A total of 618…

We conducted a high-sensitivity radio detection survey for forty narrow-line Seyfert 1 (NLS1) galaxies using very-long-baseline interferometry (VLBI) at 22 GHz through phase-referencing long-time integration and using a newly developing…

We present $4-12$ GHz in-band spectral energy distributions with accompanying 6 GHz and 10 GHz imaging results for a volume-complete sample ($<40$ Mpc) of hard X-ray selected active galactic nuclei (AGNs) observed with the Karl G. Jansky…

The Low-Frequency Array (LOFAR) Long-Baseline Calibrator Survey (LBCS) was conducted between 2014 and 2019 in order to obtain a set of suitable calibrators for the LOFAR array. In this paper we present the complete survey, building on the…

We use the Very Long Baseline Array to conduct high precision astrometry of a sample of 33 compact, flat spectrum, variable radio sources in the direction of the Galactic plane (Becker et al. 2010). Although Becker et al. (2010) ruled out a…

Very long baseline interferometry (VLBI) technique allows us to determine positions of thousands of radio sources using the absolute astrometry approach. I have investigated the impact of a selection of observing frequencies in a range from…

We present results of multifrequency polarimetric VLBA observations of 34 compact radio sources. The observations are part of a large survey undertaken to identify CSOs Observed in the Northern Sky (COINS). Compact Symmetric Objects (CSOs)…

The past decade has seen significant advances in wide-field cm-wave very long baseline interferometry (VLBI), which is timely given the wide-area, synoptic survey-driven strategy of major facilities across the electromagnetic spectrum.…