Radio interferometry and its application to arrays of element antennas enable sensitive
studies of celestial objects with angular resolutions comparable with, or surpassing, optical …

Very-long-baseline interferometry (VLBI) is a challenging observational technique, which
requires in-depth knowledge about radio telescope instrumentation, interferometry, and the …

In April 2019, the Event Horizon Telescope (EHT) Collaboration reported the first-ever event-
horizon-scale images of a black hole, resolving the central compact radio source in the giant …

We report four novel position angle measurements of the core region M 81* at 5 GHz and 8
GHz, which confirm the presence of sinusoidal jet precession in the M 81 jet region, as …

We present very long baseline interferometry (VLBI) observations of a continuum radio
source potentially associated with the fast radio burst source FRB 20190520B. Using the …

The Event Horizon Telescope (EHT) has imaged M87*, the 6.5× 109Me supermassive black
hole in the M87 galaxy, in both total intensity (Event Horizon Telescope Collaboration et al …

We analyze a single-epoch Global mm-VLBI Array (GMVA) observation of the blazar BL
Lacertae (BL Lac) at 86 GHz from April 2021. The participation of the upgraded, phased …

In this series of papers, we present new methods of frequency-and time-dependent
instrumental polarization calibration for very long baseline interferometry (VLBI). In most …

Abstract In April 2019, the Event Horizon Telescope (EHT) Collaboration reported the first-
ever event-horizon-scale images of a black hole, resolving the central compact radio source …

The first images of the black holes in Sagittarius A* and M87* have created a wide range of
new scientific opportunities in gravitational physics, compact objects, and relativistic …