39 citations · 223 across the 22 of their papers we have counts for
19 papers · 1 filter
Extreme Enrichment at Cosmic Dawn: Three FeII-Strong Quasars at z > 6 from the JWST Aether survey
Anniek J. Gloudemans, Emanuele Paolo Farina, Roberto Decarli +22
We present three outliers on the quasar main sequence at z>6, as revealed by JWST/NIRSpec IFU observations from the Aether survey, a program targeting ~200 quasars at cosmic dawn.…
The most extreme high-z radio quasars in the eRASS:1 X-ray survey
L. Ighina, L. Palmieri, L. N. Martínez-Ramírez +7
We present the selection and identification of high-z radio quasars from a combination of X-ray (eROSITA All-Sky Survey), optical/NIR (DECam Local Volume Exploration), and radio (R…
The Road to Identifying the Earliest Radio-Powerful AGN with the SKA
Jose Afonso, Stergios Amarantidis, Stas Shabala +20
The Epoch of Reionization (EoR) is one of the most pivotal frontiers in modern astrophysics, marking the emergence of the first galaxies, stars, and supermassive black holes (SMBHs…
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…
Milliarcsecond-resolution Radio-imaging Survey of Blazar Candidates at 4 < z < 5.4
Máté Krezinger, Alessandro Caccianiga, Daniele Dallacasa +9
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…
X-ray investigation of possible super-Eddington accretion in a radio-loud quasar at
L. Ighina, A. Caccianiga, T. Connor +19
We present radio and X-ray observations of the recently discovered radio-powerful quasar RACS J032021.44352104.1 using uGMRT, ATCA, LBA, and Chandra. The observed radio…
The Centre of Attention: a Powerful Radio Galaxy Pinpoints a NIR-Dark Protocluster at z~3.9
A. J. Hedge, N. Seymour, J. W. Broderick +8
We report the discovery of a protocluster identified from Atacama Large Millimetre/sub-millimetre Array Band 3 spectral scans of a bright radio source selected from the…
High- radio Quasars in RACS I: Selection, identification, and multi-wavelength properties
L. Ighina, A. Caccianiga, A. Moretti +21
Radio-bright, jetted quasars at serve as unique laboratories for studying supermassive black hole activity in the early Universe. In this work, we present a sample of high-$z…
ESPRESSO reveals a single but perturbed broad-line region in the supermassive black hole binary candidate PG 1302-102
Fabio Rigamonti, Paola Severgnini, Erika Sottocorno +12
We present a new, Bayesian analysis of the highest-resolution optical spectrum of the supermassive black hole (SMBH) binary candidate PG 1302-102, obtained with ESPRESSO@VLT (R \si…
Multi-wavelength properties of three new radio-powerful quasi-stellar objects discovered from RACS
L. Ighina, A. Caccianiga, A. Moretti +12
We present a multi-wavelength study of three new quasi-stellar objects (QSOs) identified from dedicated spectroscopic observations. The three sources were selected as hi…
Comprehensive view on a radio-loud QSO: from the radio to the optical/NIR to the X-ray band
Luca Ighina, Alessandro Caccianiga, Alberto Moretti +9
We present a multi-wavelength analysis, from the radio to the X-ray band, of the redshift VIK J231831 radio-loud (RL) quasi stellar object (QSO), one of the most distan…
Obscuration in high redshift jetted QSO
A. Caccianiga, L. Ighina, A. Moretti +6
Obscuration in high-redshift quasi-stellar objects (QSO) has a profound impact on our understanding of the evolution of supermassive black holes across the cosmic time. An accurate…
New Radio-Loud QSOs at the end of the Re-ionisation Epoch
L. Ighina, A. Caccianiga, A. Moretti +5
We present the selection of high-redshift () radio-loud (RL) quasi-stellar object (QSO) candidates from the combination of the radio Rapid ASKAP Continuum Survey (RACS…
Impact of the CMB on the evolution of AGNs and their relativisitc jets at the highest redshift
Luca Ighina
Radio-Loud (RL) Active Galactic Nuclei (AGNs) are among the brightest astrophysical sources at all wavelengths. Their relativistic jets can affect both their Supermassive Black Hol…
Constraining the Radio Properties of the =6.44 QSO VIK J23183113
Luca Ighina, James K. Leung, Jess W. Broderick +19
The recent detection of the quasi-stellar object (QSO) VIKING J231818.3311346 (hereafter VIK J23183113) at redshift in the Rapid ASKAP Continuum Survey (RACS) uncove…
The Impact of the CMB on the Evolution of high-z Blazars
L. Ighina, A. Caccianiga, A. Moretti +3
Different works have recently found an increase of the average X-ray-to-radio luminosity ratio with redshift in the blazar population. We evaluate here whether the inverse Compton…
Radio Detection of VIK J23183113, the Most Distant Radio-Loud Quasar (=6.44)
L. Ighina, S. Belladitta, A. Caccianiga +4
We report the 888 MHz radio detection in the Rapid ASKAP Continuum Survey (RACS) of VIK J23183113, a =6.44 quasar. Its radio luminosity (1.2 W Hz at 5…
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…
The space density of z>4 blazars
Alessandro Caccianiga, Alberto Moretti, Silvia Belladitta +9
High redshift blazars are an important class of Active Galactic Nuclei (AGN) that can provide an independent estimate of the supermassive black-hole mass function in high redshift…