395 citations · 2.4k across the 119 of their papers we have counts for
7 papers · 2 filters
Milliarcsecond-scale radio structure of the most distant BL Lac object candidate at redshift 6.57
S. Frey, Y. Zhang, K. Perger +7
The existence of accreting supermassive black holes up to billions of solar masses at early cosmological epochs (in the context of this work, redshifts z>=6) requires very fast gro…
From binary to singular: the AGN PSO J334.2028+1.4075 under the high-resolution scope
P. Benke, K. É. Gabányi, S. Frey +6
PSO J334.2028+1.4075 (PSO J334) is a luminous quasar located at redshift z=2.06. The source gained attention when periodic flux density variations were discovered in its optical li…
The Detection of a Compact Radio Feature in a Seyfert Galaxy After an Accretion Rate Change
K. É. Gabányi, K. Smith, S. Frey +3
X-ray binaries are known to show state transitions related to accretion rate changes which are often accompanied with dramatic changes in the jet emission. However, it is not clear…
Astrometric Apparent Motion of High-redshift Radio Sources
Oleg Titov, Sandor Frey, Alexei Melnikov +10
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 s…
Intermediate-mass black holes: finding of episodic, large-scale and powerful jet activity in a dwarf galaxy
Jun Yang, Zsolt Paragi, Sándor Frey +10
Dwarf galaxies are characterised by a very low luminosity and low mass. Because of significant accretion and ejection activity of massive black holes, some dwarf galaxies also host…
Very long baseline interferometry observations of the high-redshift blazar candidate J0141-5427
K. É. Gabányi, S. Belladitta, S. Frey +7
Active galactic nuclei (AGN) have been observed as far as redshift z~7. They are crucial in investigating the early Universe as well as the growth of supermassive black holes at th…
High-resolution Imaging of Two Radio Quasars at the End of the Reionization Epoch
Krisztina Perger, Yingkang Zhang, Sándor Frey +7
There are approximately 250 quasars discovered at redshift , of which only a handful were detected in radio bands, and even fewer were imaged with the highest resolution ve…