Publications (35)
Fireworks at Cosmic Dawn: relieving BAO-CMB tensions with the Pop III.1 Flash
Yash Aggarwal, Christopher Cain, Garett Lopez +4
A Cosmic Microwave Background (CMB) optical depth of , several in excess of the latest Planck low- EE polarization measurement, has been proposed as a way t…
Imaging reionization's last phases with I-front Lyman- emissions
Bayu Wilson, Anson D'Aloisio, George D. Becker +2
Long troughs observed in the Ly and Ly forests are thought to be caused by the last remaining neutral patches during the end phases of reionization -- termed neut…
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 me…
Galaxy Underdensities Host the Clearest IGM Ly Transmission and Indicate Anisotropic Reionization
Yongda Zhu, George D. Becker, Anson D'Aloisio +6
How galaxies drive reionization and what governs its geometry remain fundamental questions. We present JWST/NIRCam wide-field slitless spectroscopy (WFSS) observations toward two o…
A Potential Link between Nuclear Winds and Cold Gas Outflows on Kiloparsec Scales in Reionization-Era Quasars
Yongda Zhu, Marcia J. Rieke, Luis C. Ho +23
Feedback from accreting supermassive black holes may regulate galaxy evolution, but statistical evidence linking nuclear winds to kiloparsec-scale cold gas outflows remains limited…
Kiloparsec-scale turbulence driven by reionization may grow intergalactic magnetic fields
Christopher Cain, Matthew McQuinn, Evan Scannapieco +2
The intergalactic medium (IGM) underwent intense heating that resulted in pressure disequilibrium in the wake of ionization fronts during cosmic reionization. The dynamical relaxat…
Quantifying Lyman- emissions from reionization fronts
Bayu Wilson, Anson D'Aloisio, Christopher Cain +2
During reionization, intergalactic ionization fronts (I-fronts) are sources of Ly line radiation produced by collisional excitation of hydrogen atoms within the fronts. In prin…
Discovery of a Unique Close Quasar-DSFG Pair Linked by a [C II] Bridge at
Yongda Zhu, Tom J. L. C. Bakx, Ryota Ikeda +11
We report the discovery of a unique quasar-dusty star-forming galaxy (DSFG) system at , consisting of the bright quasar J1133+1603 () and its compact…
A long time ago in an LAE far, far away: a signpost of early reionization or a nascent AGN at ?
Joshua Cohon, Christopher Cain, Rogier Windhorst +3
The JADES survey recently reported the discovery of JADES-GS-z13-1-LA at , the highest redshift Ly emitter (LAE) ever observed. This observation suggests that either th…
The effect of reionization on direct measurements of the mean free path
Joshua T. Roth, Anson D'Aloisio, Christopher Cain +3
Recent measurements of the ionizing photon mean free path (MFP) based on composite quasar spectra may point to reionization ending at . These measurements are challenging beca…
Characterising the epoch of reionisation using the cross-correlation of the kSZ effect and CMB lensing
Niall MacCrann, Christopher Cain, Aleksandra Kusiak +5
We investigate the cross-correlation of the kinematic Sunyaev-Zeldovich (kSZ) effect with lensing of the cosmic microwave background (CMB) as a probe of the epoch of reionisation.…
Towards an accurate treatment of the reduced speed of light approximation in parameterized radiative transfer simulations of reionization
Christopher Cain
The reduced speed of light approximation (RSLA) has been employed to speed up radiative transfer simulations of reionization by a factor of . However, it has been sho…
New constraints on the galactic ionizing efficiency and escape fraction at 2.5 < z < 6 based on quasar absorption spectra
Christopher Cain, Anson D'Aloisio, Julian B. Munoz
Measurements of the ionisation state of the intergalactic medium (IGM) can probe the sources of the extragalactic ionising background. We provide new measurements of the ionising e…
Bayesian estimation of cross-coupling and reflection systematics in 21cm array visibility data
Geoff G. Murphy, Philip Bull, Mario G. Santos +76
Observations with radio arrays that target the 21-cm signal originating from the early Universe suffer from a variety of systematic effects. An important class of these are reflect…
Hydrodynamic Response of the Intergalactic Medium to Reionization
Anson D'Aloisio, Matthew McQuinn, Hy Trac +2
The intergalactic medium is expected to clump on scales down to M before the onset of reionization. The impact of these small-scale structures on reionization…
An emulator for the ionizing photon mean free path in ultra-high resolution simulations: the implications of mean free path measurements for the reionization history
Hurum Maksora Tohfa, Christopher Cain, Matthew McQuinn +1
Measurements of the mean free path of ionizing photons from high-redshift quasar spectra at - constrain the reionization history, but interpreting them requires modeli…
Introducing SAGUARO -- Simulating IGM Evolution and Environments At High Resolution: Setup and First Results
Christopher Cain, Aloha Das, Anson D'Aloisio +7
Small-scale physics in the intergalactic medium (IGM) plays a crucial role in shaping the progress of cosmic reionization and several high-redshift observables that probe this peri…
Cross-correlating the patchy screening and kinetic Sunyaev-Zel'dovich effects as a new probe of reionization
Darby Kramer, Alexander van Engelen, Christopher Cain +5
The kinetic Sunyaev-Zel'dovich effect (kSZ) and patchy screening effect are two complementary cosmic microwave background (CMB) probes of the reionization era. The kSZ effect is a…
The CMB optical depth constrains the duration of reionization
Christopher Cain, Alexander Van Engelen, Kevin S. Croker +3
Recently, it was pointed out that invoking a large value of the CMB optical depth, , could help resolve tensions between DESI DR2 BAO data and the CMB. This is…
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…
The Morphology of Reionization in a Dynamically Clumpy Universe
Christopher Cain, Anson D'Aloisio, Nakul Gangolli +1
A recent measurement of the Lyman-limit mean free path at suggests it may have been very short, motivating a better understanding of the role that ionizing photon sinks pla…
Quasar Radiative Feedback May Suppress Galaxy Growth on Intergalactic Scales at
Yongda Zhu, Eiichi Egami, Xiaohui Fan +27
We present observational evidence that intense ionizing radiation from a luminous quasar suppresses nebular emission in nearby galaxies on intergalactic scales at . Using JW…
On the correlation between Ly forest opacity and galaxy density in late reionization models
Nakul Gangolli, Anson D'Aloisio, Christopher Cain +2
The relationship between Ly forest opacity and local galaxy density (the opacity-density relation) is a key observational test of late reionization models. Using narrow-band su…
matvis: A matrix-based visibility simulator for fast forward modelling of many-element 21 cm arrays
Piyanat Kittiwisit, Steven G. Murray, Hugh Garsden +95
Detection of the faint 21 cm line emission from the Cosmic Dawn and Epoch of Reionisation will require not only exquisite control over instrumental calibration and systematics to a…
Probing the ionizing photon output of galaxies near cosmic dawn with the patchy kSZ effect
Garett Lopez, Anson D'Aloisio, Christopher Cain
A key result from JWST's first cycles is that galaxy formation was well underway by . The implications of these early galaxies for reionization are less clear, however. The C…
Small-scale clumping of dark matter and the mean free path of ionizing photons at
Christopher Cain, Anson D'Aloisio, Vid Irsic +2
Recently, the mean free path of ionizing photons in the intergalactic medium (IGM) was measured to be very short, presenting a challenge to existing reionization models. At…
Hydrodynamic Response of the Intergalactic Medium to Reionization II: Physical Characteristics and Dynamics of Ionizing Photon Sinks
Fahad Nasir, Christopher Cain, Anson D'Aloisio +2
Becker et al. 2021 measured the mean free path of Lyman limit photons in the IGM at . The short value suggests that absorptions may have played a prominent role in reionizatio…
A short mean free path at favors late and rapid reionization by faint galaxies
Christopher Cain, Anson D'Aloisio, Nakul Gangolli +1
Recent measurements of the ionizing photon mean free path () at suggest that the IGM was rapidly evolving at those times. We use radiative transfer…
FlexRT -- A fast and flexible cosmological radiative transfer code for reionization studies I: Code validation
Christopher Cain, Anson D'Aloisio
The wealth of high-quality observational data from the epoch of reionization that will become available in the next decade motivates further development of modeling techniques for…
On the rise and fall of galactic ionizing output at the end of reionization
Christopher Cain, Anson D'Aloisio, Garett Lopez +2
Quasar absorption spectra measurements suggest that reionization proceeded rapidly, ended late at , and was followed by a flat ionizing background evolution. Simulation…
Can high-redshift AGN observed by JWST explain the EDGES absorption signal?
Alexandra Nelander, Christopher Cain, Jordan C J DSilva +3
The Experiment to Detect the Global Epoch of Reionization 21 cm Signal (EDGES) has reported evidence for an absorption feature in the sky-averaged radio background near 78 MHz. A c…
Chasing the beginning of reionization in the JWST era
Christopher Cain, Garett Lopez, Anson D'Aloisio +4
Recent JWST observations at may imply galactic ionizing photon production above prior expectations. Under observationally motivated assumptions about escape fractions, thes…
A self-consistent analytical model for both the photoionization rate and reionization history
Christopher Cain, Kevin S. Croker, Anson D'Aloisio +4
Recent developments at the intersection of cosmology and astrophysics have highlighted the need for improved analytical models of observables that probe the Epoch of Reionization.…
A Model-Insensitive Baryon Acoustic Oscillation Feature in the 21 cm Signal from Reionization
Christopher Cain, Anson D'Aloisio, Vid IrÅ¡iÄ +2
We examine the impact of baryon-dark matter relative velocities on intergalactic small-scale structure and the 21 cm signal during reionization. Streaming velocities reduced clumpi…
The hydrodynamic response of small-scale structure to reionization drives large IGM temperature fluctuations that persist to z = 4
Christopher Cain, Evan Scannapieco, Matthew McQuinn +2
The thermal history and structure of the intergalactic medium (IGM) at is an important boundary condition for reionization, and a key input for studies using the Ly…