91 citations · 442 across the 28 of their papers we have counts for
29 papers
Nearly pristine gas in a galaxy 1 billion years after the Big Bang
Sarah E. I. Bosman, Frederick B. Davies, Louise Welsh +22
Excitation of carbon and oxygen ions is the primary mechanism by which collapsing gas clouds dissipate heat to form new stars. At early cosmic times, in galaxies with chemically pr…
OzSSy1: The Australian Southern Seyfert-1 Spectroscopic Atlas and Catalogue at z < 0.1
Neelesh Amrutha, Christian Wolf, Christopher A. Onken +3
We present a spectroscopic atlas of 887 broad-line active galactic nuclei (AGNs) in the Southern sky, spanning redshifts , declinations deg and Galactic latitudes $…
Updated dark pixel fraction constraints on reionization's end from the Lyman-series forests of XQR-30
Frederick B. Davies, Sarah E. I. Bosman, Valentina D'Odorico +16
The fraction of "dark pixels" in the Ly and other Lyman-series forests at provides a powerful constraint on the end of the reionization process. Any spectral region…
The clustering of C IV and Si IV at the end of reionisation: A perspective from the E-XQR-30 survey
Louise Welsh, Valentina D'Odorico, Fabio Fontanot +14
We aim to study the clustering of metal absorption lines and the structures that they arise in as a function of cosmic time. We focus on C IV and Si IV absorption features that are…
Percent-level timing of reionization: self-consistent, implicit-likelihood inference from XQR-30+ Ly forest data
Yuxiang Qin, Andrei Mesinger, David Prelogović +13
The Lyman alpha (Lya) forest in the spectra of z>5 quasars provides a powerful probe of the late stages of the Epoch of Reionization (EoR). With the recent advent of exquisite data…
Discovering Changing-Look AGN in the 6dF Galaxy Survey using ATLAS Light curves
Neelesh Amrutha, Christian Wolf, Christopher A. Onken +4
Changing-Look Active Galactic Nuclei (CLAGN) are characterised by extreme variations in line emission over short timescales, mostly affecting broad H lines. While a few hundred…
No Redshift Evolution in the Fe II/Mg II Flux Ratios of Quasars across Cosmic Time
Danyang Jiang, Masafusa Onoue, Linhua Jiang +13
The Fe II/Mg II emission line flux ratio in quasar spectra serves as a proxy for the relative Fe to alpha-element abundances in the broad line regions of quasars. Due to the expect…
Damping Wing-Like Features in the Stacked Ly Forest: Potential Neutral Hydrogen Islands at
Yongda Zhu, George D. Becker, Sarah E. I. Bosman +28
Recent quasar absorption line observations suggest that reionization may end as late as . As a means to search for large neutral hydrogen islands at , we revisi…
Supermassive black holes are growing slowly by
Samuel Lai, Christopher A. Onken, Christian Wolf +2
We investigate the black hole mass function at using XQz5, our recent sample of the most luminous quasars between the redshifts . We include 72 quasars with…
Multi-phase black-hole feedback and a bright [CII] halo in a Lo-BAL quasar at
Manuela Bischetti, Hyunseop Choi, Fabrizio Fiore +18
Although the mass growth of supermassive black holes during the Epoch of Reionisation is expected to play a role in shaping the concurrent growth of their host-galaxies, observatio…
IGM damping wing constraints on the tail end of reionisation from the enlarged XQR-30 sample
Bradley Greig, Andrei Mesinger, Eduardo Bañados +16
The attenuation of Ly photons by neutral hydrogen in the intergalactic medium (IGM) at continues to be a powerful probe for studying the epoch of reionisation. Given…
Evidence of Pop~III stars' chemical signature in neutral gas at z~6. A study based on the E-XQR-30 spectroscopic sample
Alessio Sodini, Valentina D'Odorico, Stefania Salvadori +16
This study explores the metal enrichment signatures attributed to the first generation of stars (PopIII) in the Universe, focusing on the E-XQR-30 sample. We aim to identify traces…
E-XQR-30: The evolution of MgII, CII and OI across 2<z<6
Alma Maria Sebastian, Emma Ryan-Weber, Rebecca L. Davies +12
Intervening metal absorbers in quasar spectra at can be used as probes to study the chemical enrichment of the Universe during the Epoch of Reionization (EoR). This work pr…
The accretion of a solar mass per day by a 17-billion solar mass black hole
Christian Wolf, Samuel Lai, Christopher A. Onken +5
Around a million quasars have been catalogued in the Universe by probing deeper and using new methods for discovery. However, the hardest ones to find seem to be the rarest and bri…
Constraints on the Evolution of the Ionizing Background and Ionizing Photon Mean Free Path at the End of Reionization
Frederick B. Davies, Sarah E. I. Bosman, Prakash Gaikwad +16
The variations in Ly forest opacity observed at between lines of sight to different background quasars are too strong to be caused by fluctuations in the density field a…
XQz5: A New Ultraluminous z5 Quasar Legacy Sample
Samuel Lai, Christopher Onken, Christian Wolf +2
Bright quasar samples at high redshift are useful for investigating active galactic nuclei evolution. In this study, we describe XQz5, a sample of 83 ultraluminous quasars in the r…
Virial Black Hole Mass Estimates of Quasars in the XQ-100 Legacy Survey
Samuel Lai, Christopher A. Onken, Christian Wolf +4
The black hole (BH) mass and luminosity are key factors in determining how a quasar interacts with its environment. In this study, we utilise data from the European Southern Observ…
Measurements of the Lyman- forest flux auto-correlation functions from the extended XQR-30 data set
Molly Wolfson, Joseph F. Hennawi, Sarah E. I. Bosman +14
Recently, the Lyman- (Ly) forest flux auto-correlation function has been shown to be sensitive to the mean free path of hydrogen-ionizing photons, , for simul…
Probing Ultra-late Reionization: Direct Measurements of the Mean Free Path over
Yongda Zhu, George D. Becker, Holly M. Christenson +22
The mean free path of ionizing photons, , is a critical parameter for modeling the intergalactic medium (IGM) both during and after reionization. We present direct mea…
XQR-30: Black Hole Masses and Accretion Rates of 42 z>6 Quasars
C. Mazzucchelli, M. Bischetti, V. D'Odorico +19
We present bolometric luminosities, black hole masses and Eddington ratios for 42 luminous quasars at z>6 using high signal-to-noise ratio VLT/X-Shooter spectra, acquired in the en…
XQR-30: the ultimate XSHOOTER quasar sample at the reionization epoch
Valentina D'Odorico, E. Banados, G. D. Becker +46
The final phase of the reionization process can be probed by rest-frame UV absorption spectra of quasars at z>6, shedding light on the properties of the diffuse intergalactic mediu…
Probing Quasar Viewing Angle with the Variability Structure Function
Ji-Jia Tang, Christian Wolf, John Tonry +3
Given the anisotropic emission from quasar accretion discs, their viewing angle affects estimates of the quasar luminosity, black-hole mass and Eddington ratio. Discs appear overlu…
New quasar proximity zone size measurements at using the enlarged XQR-30 sample
Sindhu Satyavolu, Anna-Christina Eilers, Girish Kulkarni +15
Proximity zones of high-redshift quasars are unique probes of their central supermassive black holes as well as the intergalactic medium in the last stages of reionization. We pres…
Measuring the photo-ionization rate, neutral fraction and mean free path of HI ionizing photons at from a large sample of XShooter and ESI spectra
Prakash Gaikwad, Martin G. Haehnelt, Frederick B. Davies +16
We measure the mean free path (), photo-ionization rate () and neutral fraction () of hydrogen in 12 redshif…