Related papers: Higher Resolution VLBI Imaging with Fast Frequency…

Many of the compact extragalactic radio sources that are used as fiducial points to define the celestial reference frame are known to have proper motions detectable with long-term geodetic/astrometric Very Long Baseline Interferometry…

We have used the European VLBI Network (EVN) to observe a sample of Lyman Break Analogs (LBAs), nearby (z < 0.3) galaxies with properties similar to the more distant Lyman Break Galaxies (LBGs). The study of LBGs may help define the…

Context. Blazars are among the most energetic objects in the Universe. In 2008 August, Fermi/LAT detected the blazar PKS 1502+106 showing a rapid and strong gamma-ray outburst followed by high and variable flux over the next months. This…

We present the design and implementation of an automated data calibration and reduction pipeline for very-long-baseline interferometric (VLBI) observations taken at millimeter wavelengths. These short radio-wavelengths provide the best…

We present a case for significantly enhancing the utility and efficiency of the ngEHT by incorporating an additional 86 GHz observing band. In contrast to 230 or 345 GHz, weather conditions at the ngEHT sites are reliably good enough for 86…

We present a milliarcsecond-resolution radio survey of 17 high-redshift (4 < z < 5.4) blazar candidates observed with the European Very Long Baseline Interferometry (VLBI) Network at 5 GHz. The primary objective of this study was to…

We present the results of a program to monitor the structure of the radio emission in 42 $\gamma$-ray bright blazars (31 quasars and 11 BL Lac objects) with the VLBA at 43, 22, and occasionally 15 and 8.4 GHz, over the period from November…

Radio observations using the Very Long Baseline Interferometry (VLBI) technique typically have fields of view of only a few arcseconds, due to the computational problems inherent in imaging larger fields. Furthermore, sensitivity…

We introduce the cross spectrum based FRB (Fast Radio Burst) search method for VLBI observation. This method optimizes the fringe fitting scheme in geodetic VLBI data post processing, which fully utilizes the cross spectrum fringe phase…

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…

Centaurus A is the closest active galactic nucleus. High resolution imaging using Very Long Baseline Interferometry (VLBI) enables us to study the spectral and kinematic behavior of the radio jet-counterjet system on sub-parsec scales,…

When comparing modern fundamental reference frames in the radio (International Celestial Reference Frame) and optical (Gaia), a couple of bright radio reference sources appear to have very large radio-optical offsets, from tens up to…

In recent years, the jet formation region in active galaxies has been imaged through mm-VLBI in few ideal targets, first and foremost M87. An important leap forward for understanding jet launching could be made by identifying a larger…

Many important techniques for investigating the properties of extragalactic radio sources, such as spectral-index and rotation-measure mapping, involve the comparison of images at two or more frequencies. In the case of radio…

(Abridged) Conventional radio surveys of deep fields ordinarily have arc-second scale resolutions often insufficient to reliably separate radio emission in distant galaxies originating from star-formation and AGN-related activity. Very long…

Multi-epoch Very Long Baseline Interferometry (VLBI) study of the sub-pc scale jet of 3C 84 is presented. We carried out 14-epoch VLBI observations during 2006-2009 with the Japanese VLBI Network (JVN) and the VLBI Exploration of Radio…

We have carried out a high-precision astrometric analysis of two very-long-baseline-interferometry (VLBI) epochs of observation of the 13 extragalactic radio sources in the complete S5 polar cap sample. The VLBI epochs span a time baseline…

In this paper, we propose a new approach to determining cosmological distances to active galactic nuclei (AGN) via light travel-time arguments, which can be extended from nearby sources to very high redshift sources. The key assumption is…

In April 2002 an array of antennas operating at 129GHz successfully detected VLBI fringes on both continuum AGN and SiO maser sources. The 129GHz fringes on maser sources represent the highest frequency spectral line VLBI detections to…

The sub/millimeter wavelengths (86-690 GHz) very long baseline interferometry (VLBI) will provide $\sim5-40\ \mu$as angular resolution, $\sim10$ mJy baseline sensitivity, and $\sim 1\ \mu$as/yr proper motion precision, which can directly…