56 citations · 282 across the 26 of their papers we have counts for
27 papers
From compact jets to extended lobes: radio morphologies of distant quasars at z > 4
K. É. Gabányi, M. Kunert-Bajraszewska, A. Krauze +9
High-redshift quasars play an essential role in studying the growth and evolution of supermassive black holes and active galactic nuclei (AGN). Radio-loud quasars additionally enab…
SKAVLBI view of AGN jets in the early Universe
C. Spingola, M. Mezcua, Y. Liu +33
Active Galactic Nuclei (AGN) are among the brightest sources in the Universe, and those that are also jetted are uniquely valuable at the earliest epochs, because their relativisti…
Revealing faint compact radio jets at redshifts above 5 with very long baseline interferometry
Máté Krezinger, Giovanni Baldini, Marcello Giroletti +6
Over the past two decades, our knowledge of the high-redshift (z > 5) radio quasars has expanded, thanks to dedicated high-resolution very long baseline interferometry (VLBI) obser…
European VLBI Network observations of the peculiar radio source 4C 35.06 overlapping with a compact group of nine galaxies
Patrik Milán Veres, Krisztina Éva Gabányi, Sándor Frey +8
Context. According to the hierarchical structure formation model, brightest cluster galaxies (BCGs) evolve into the most luminous and massive galaxies in the Universe through multi…
JWST Reveals Powerful Feedback from Radio Jets in a Massive Galaxy at z = 4.1
Namrata Roy, Timothy Heckman, Roderik Overzier +11
We report observations of a powerful ionized gas outflow in a z = 4.1 luminous () radio galaxy TNJ1338-1942 hosting an obscured quasar usi…
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…
Follow-up on the Supermassive Black Hole Binary Candidate J1048+7143: Successful Prediction of the Next Gamma-ray Flare and Refined Binary Parameters in the Framework of Jet Precession Model
Emma Kun, Ilja Jaroschewski, Julia Becker Tjus +6
Analyzing single-dish and VLBI radio, as well as \textit{Fermi}-LAT -ray observations, we explained the three major flares in the -ray light curve of FSRQ J1048+7143 with the…
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…
J2102+6015: an Intriguing Radio-loud Active Galactic Nucleus in the Early Universe
S. Frey, T. An, K. Gabányi +10
The powerful high-redshift quasar J2102+6015 (at z=4.575) may provide useful information for studying supermassive black hole growth, galaxy evolution and feedback in the early Uni…
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…
Radio-loud Quasars above Redshift 4: VLBI Imaging of an Extended Sample
M. Krezinger, K. Perger, K. É. Gabányi +7
High-redshift radio sources provide plentiful opportunities for studying the formation and evolution of early galaxies and supermassive black holes. However, the number of known ra…
Searching for the Origin of Double-peaked Broad Emission Lines in a Merging Galaxy with EVN
Krisztina É. Gabányi, Sándor Frey, Emma Kun +2
The current cosmological structure formation models predict that galaxies evolve through frequent mergers. During these events, the supermassive black holes (SMBHs) residing in the…
A long-lived compact jet in the black hole X-ray binary candidate AT2019wey
Hong-Min Cao, Giulia Migliori, Marcello Giroletti +7
AT2019wey is a transient discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) survey in December of 2019. Follow-up optical, radio, and X-ray observations led to…
Very Long Baseline Interferometry Observations of the Proposed Radio Counterpart of an EGRET Source
Patrik Milán Veres, Krisztina Éva Gabányi, Sándor Frey
We present high-resolution radio interferometric imaging observations of the radio source NVSS J182659+343113 (hereafter J1826+3431), the proposed radio counterpart of the -ray…
VLBI20-30: a scientific roadmap for the next decade -- The future of the European VLBI Network
Tiziana Venturi, Zsolt Paragi, Michael Lindqvist +77
This white paper describes the science case for Very Long Baseline Interferometry (VLBI) and provides suggestions towards upgrade paths for the European VLBI Network (EVN). The EVN…
Very long baseline interferometry observation of the triple AGN candidate J0849+1114
Krisztina Éva Gabányi, Sándor Frey, Shobita Satyapal +2
In the hierarchical structure formation model, galaxies grow through various merging events. Numerical simulations indicate that the mergers can enhance the activity of the central…
The rare extended radio-loud narrow-line Seyfert 1 galaxy SDSS J1030+5516 at high resolution
Krisztina Éva Gabányi, Sándor Frey, Péter Veres +1
Recently, Rakshit et al. (2018) reported the discovery of SDSS J103024.95551622.7, a radio-loud narrow-line Seyfert 1 galaxy having a kpc scale double-lobed radio str…
Three little radio galaxies in the early Universe
K. É. Gabányi, S. Frey, Z. Paragi +7
Volonteri et al. (2011) found that the number of radio-loud quasars above redshift 4 calculated from the luminosity function (based upon Swift/BAT observations) is much smaller tha…
Infrared variability of radio-loud narrow-line Seyfert 1 galaxies
K. É. Gabányi, A. Moór, S. Frey
Most of the radio-loud narrow-line Seyfert 1 (NLS1) galaxies resemble compact steep-spectrum sources. However, the extremely radio-loud ones show blazar-like characteristics, like…
VLBI observations of four radio quasars at : blazars or not?
H. -M. Cao, S. Frey, K. É. Gabányi +5
Blazars are active galactic nuclei (AGN) whose relativistic jets point nearly to the line of sight. Their compact radio structure can be imaged with very long baseline interferomet…
On the nature of bright compact radio sources at z>4.5
Rocco Coppejans, Sándor Frey, Dávid Cseh +7
High-redshift radio-loud quasars are used to, among other things, test the predictions of cosmological models, set constraints on black hole growth in the early universe and unders…
Parsec-scale jet properties of the quasar PG 1302102
P. Mohan, T. An, S. Frey +3
The quasar PG 1302102 is believed to harbour a supermassive binary black hole (SMBBH) system. Using the available 15 GHz and GHz, multi-epoch Very Long Baseline Array data…
VLBI observation of the newly discovered z=5.18 quasar SDSS J0131-0321
K. E. Gabanyi, D. Cseh, S. Frey +4
Few high-redshift, radio-loud quasars are known to date. The extremely luminous, radio-bright quasar, SDSS J013127.34-032100.1 was recently discovered at a redshift of . We…
A single radio-emitting nucleus in the dual AGN candidate NGC 5515
K. É. Gabányi, S. Frey, T. Xiao +4
The Seyfert galaxy NGC 5515 has double-peaked narrow-line emission in its optical spectrum, and it has been suggested that this could indicate that it has two active nuclei. We obs…