450 citations · 2.1k across the 56 of their papers we have counts for
14 papers · 1 filter
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…
The SRG/eROSITA All-Sky Survey: X-ray beacons at late cosmic dawn
J. Wolf, M. Salvato, S. Belladitta +12
The SRG/eROSITA All-Sky Survey (eRASS) is expected to contain ~100 quasars that emitted their light when the universe was less than a billion years old, i.e. at z>5.6. By selection…
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…
A small radio galaxy at z=4.026
Krisztina É. Gabányi, Sándor Frey, Tao An +8
Less than radio-loud active galactic nuclei (AGN) are known above redshift . Around of them have been observed at milliarcsecond (mas) scale resolution with very long…
Difficulties in Mid-Infrared selection of AGN in dwarf galaxies
Alessandro Lupi, Tullia Sbarrato, Stefano Carniani
While massive black holes (MBHs) are known to inhabit all massive galaxies, their ubiquitous presence in dwarf galaxies has not been confirmed yet, with only a limited number of so…
Searching for Super-Eddington Quasars using a Photon Trapping Accretion Disc Model
Quentin Pognan, Benny Trakhtenbrot, Tullia Sbarrato +2
Accretion onto black holes at rates above the Eddington limit has long been discussed in the context of supermassive black hole (SMBH) formation and evolution, providing a possible…
An extremely X--ray weak blazar at z=5
S. Belladitta, A. Moretti, A. Caccianiga +5
We present the discovery and properties of DESJ014132.4-542749.9 (DES0141-54), a new powerful radio-loud active galactic nucleus (AGN) in the early Universe (z=5.0). It was discove…
On the orientation of Narrow Line Seyfert I
Tullia Sbarrato, Massimo Dotti, Giancarlo Ghirlanda +1
We study a sample of Narrow-line Seyfert 1 galaxies (NLS1) in their optical and radio features, in order to understand the differences between their radio silent, radio-loud and ra…
AGN mass estimates in large spectroscopic surveys: the effect of host galaxy light
Ludovica Varisco, Tullia Sbarrato, Giorgio Calderone +1
Virial-based methods for estimating active supermassive black hole masses are now commonly used on extremely large spectroscopic quasar catalogues. Most spectral analyses, though,…
XMM-Newton observation of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.326
Yanli Ai, A. C. Fabian, Xiaohui Fan +7
A brief Chandra observation of the ultraluminous quasar, SDSS J010013.02+280225.8 at redshift 6.326, showed it to be a relatively bright, soft X-ray source with a count rate of abo…
CMB-induced radio quenching of high-redshift jetted AGNs with highly magnetic hotspots
Jianfeng Wu, Gabriele Ghisellini, Edmund Hodges-Kluck +5
In an effort to understand the cause of the apparent depletion in the number density of radio-loud AGNs at , this work investigates the viability of the so-called Cosmic Micro…
Faint progenitors of luminous quasars: why don't we see them?
Edwige Pezzulli, Rosa Valiante, Maria C. Orofino +3
Observational searches for faint active nuclei at have been extremely elusive, with a few candidates whose high- nature is still to be confirmed. Interpreting this lack…