30 citations · 157 across the 22 of their papers we have counts for
22 papers
Quasar Impostors: Two Extremely UV-Bright () Reionisation-Epoch Galaxies Powered by Very Massive Stars
Daming Yang, Joseph F. Hennawi, Sarah E. I. Bosman +20
The extreme bright end of the galaxy UV luminosity function during reionisation remains poorly constrained, particularly where the galaxy and quasar luminosity functions overlap an…
Euclid: Discovery of 31 new quasars at
D. Yang, J. F. Hennawi, F. Guarneri +211
We report the discovery of 31 new high- quasars in the redshift range . These quasars were selected from approximately 3000 deg of sky covered during the firs…
Euclid: A UV-faint quasar in a highly luminous star-forming host galaxy at
S. Belladitta, R. Decarli, E. Bañados +180
Constraining the co-evolution of supermassive black holes and their host galaxies in the first billion years after the Big Bang is essential for understanding the formation of the…
Estimating the completeness of the QUBRICS Survey with 3501 QSO redshifts from Gaia DR3 spectra
Matteo Porru, Stefano Cristiani, Francesco Guarneri +9
QSOs are essential for investigating the structure and evolution of the Universe. Historically, their identification has been concentrated in the northern hemisphere, primarily due…
The ESPRESSO Redshift Drift Experiment III -- The Third Epoch of QSO J052915.80-435152.0
Andrea Trost, Catarina M. J. Marques, S. Cristiani +25
The Sandage-Loeb test probes cosmic expansion directly by measuring the redshift drift in quasar absorption features in a model-independent way. In this series of papers, we have l…
From the Intergalactic to the Interstellar Scales -- EQUALS: a High-resolution Legacy Survey of Gas in the Distant Universe Using ESPRESSO
Trystyn Berg, Valentina D'Odorico, Elisa Boera +14
Understanding how the Universe evolved from diffuse primordial gas into the rich cosmic web we observe today is one of the great challenges of modern astrophysics. Quasar absorptio…
The ESPRESSO Redshift Drift Experiment I -- High-resolution spectra of the Lyman- forest of QSO J052915.80-435152.0
Andrea Trost, Catarina M. J. Marques, Stefano Cristiani +25
The measurement of the temporal evolution in the redshift of distant objects, the redshift drift, is a probe of universal expansion and cosmology. We perform the first steps toward…
What are the Pillars of Reionization? Revising the AGN Luminosity Function at z~5
Andrea Grazian, Emanuele Giallongo, Konstantina Boutsia +22
In the past, high-z AGNs were given a minor role as possible drivers of reionization, despite initial evidences in favor of their large space densities at low luminosities by Chand…
Probing the small scale structure of the Inter-Galactic Medium with ESPRESSO: spectroscopy of the lensed QSO UM673
Stefano Cristiani, Guido Cupani, Andrea Trost +20
The gravitationally lensed quasar J014516.6-094517 at z=2.719 has been observed with the ESPRESSO instrument at the ESO VLT to obtain high-fidelity spectra of the two images A and…
Fundamental physics with ESPRESSO: a new determination of the D/H ratio towards PKS1937-101
Francesco Guarneri, Luca Pasquini, Valentina D'Odorico +19
Primordial abundances of light elements are sensitive to the physics of the early Universe and can directly constrain cosmological quantities, such as the baryon-to-photon ratio $η…
Boost recall in QSO selection from highly imbalanced photometric datasets
Giorgio Calderone, Francesco Guarneri, Matteo Porru +9
Context. The identification of bright QSOs is of great importance to probe the intergalactic medium and address open questions in cosmology. Several approaches have been adopted to…
Crossing the Rubicon of Reionization with z~5 QSOs
A. Grazian, K. Boutsia, E. Giallongo +12
One of the key open questions in Cosmology is the nature of the sources that completed the cosmological hydrogen Reionization at z~5.2. High-z primeval galaxies have been long cons…
Advanced Data Analysis for Observational Cosmology: applications to the study of the Intergalactic Medium
Guido Cupani, Giorgio Calderone, Stefano Cristiani +1
The analysis of absorption features along the line of sight to distant sources is an invaluable tool for observational cosmology, giving a direct insight into the physical and chem…
Spectroscopy of QUBRICS quasar candidates: 1672 new redshifts and a Golden Sample for the Sandage Test of the Redshift Drift
Stefano Cristiani, Matteo Porru, Francesco Guarneri +10
The QUBRICS (QUasars as BRIght beacons for Cosmology in the Southern hemisphere) survey aims at constructing a sample of the brightest quasars with z>~2.5, observable with faciliti…
Spectrographs and Spectroscopists for the Sandage Test
S. Cristiani, K. Boutsia, G. Calderone +9
The redshift drift is a small, dynamic change in the redshift of objects following the Hubble flow. Its measurement provides a direct, real-time, model-independent mapping of the e…
Eddington accreting Black Holes in the Epoch of Reionization
Fabio Fontanot, Stefano Cristiani, Andrea Grazian +8
The evolution of the luminosity function (LF) of Active Galactic Nuclei (AGNs) at represents a key constraint to understand their contribution to the ionizing photon…
The probabilistic random forest applied to the QUBRICS survey: improving the selection of high-redshift quasars with synthetic data
Francesco Guarneri, Giorgio Calderone, Stefano Cristiani +10
Several recent works have focused on the search for bright, high-z quasars (QSOs) in the South. Among them, the QUasars as BRIght beacons for Cosmology in the Southern hemisphere (…
Near-infrared spectroscopy of extreme BAL QSOs from the QUBRICS bright quasar survey
Guido Cupani, Giorgio Calderone, Pierluigi Selvelli +8
We report on the spectral confirmation of 18 QSO candidates from the "QUasars as BRIght beacons for Cosmology in the Southern hemisphere'' survey (QUBRICS), previously observed in…
The space density of ultra-luminous QSOs at the end of reionization epoch by the QUBRICS Survey and the AGN contribution to the hydrogen ionizing background
A. Grazian, E. Giallongo, K. Boutsia +6
Motivated by evidences favoring a rapid and late hydrogen reionization process completing at z~5.2-5.5 and mainly driven by rare and luminous sources, we have reassessed the estima…
The Probabilistic Random Forest applied to the selection of quasar candidates in the QUBRICS Survey
Francesco Guarneri, Giorgio Calderone, Stefano Cristiani +5
The number of known, bright (), high-redshift () QSOs in the Southern Hemisphere is considerably lower than the corresponding number in the Northern Hemisphere due to…
The Luminosity Function of bright QSOs at z~4 and implications for the cosmic ionizing background
K. Boutsia, A. Grazian, F. Fontanot +8
Based on results by recent surveys, the number of bright quasars at redshifts z>3 is being constantly revised upwards. Current consensus is that at bright magnitudes ($M_{1450}\le…
The spectroscopic follow-up of the QUBRICS bright quasar survey
K. Boutsia, A. Grazian, G. Calderone +11
We present the results of the spectroscopic follow up of the QUBRICS survey. The selection method is based on a machine learning approach applied to photometric catalogs, covering…