kNN CDF statistics detect 21cm-galaxy cross-correlations more effectively than two-point methods and distinguish reionization models at fixed ionized fraction even with noise and foregrounds.
hub Canonical reference
Hydrogen Epoch of Reionization Array (HERA)
Canonical reference. 100% of citing Pith papers cite this work as background.
abstract
The Hydrogen Epoch of Reionization Array (HERA) is a staged experiment to measure 21 cm emission from the primordial intergalactic medium (IGM) throughout cosmic reionization ($z=6-12$), and to explore earlier epochs of our Cosmic Dawn ($z\sim30$). During these epochs, early stars and black holes heated and ionized the IGM, introducing fluctuations in 21 cm emission. HERA is designed to characterize the evolution of the 21 cm power spectrum to constrain the timing and morphology of reionization, the properties of the first galaxies, the evolution of large-scale structure, and the early sources of heating. The full HERA instrument will be a 350-element interferometer in South Africa consisting of 14-m parabolic dishes observing from 50 to 250 MHz. Currently, 19 dishes have been deployed on site and the next 18 are under construction. HERA has been designated as an SKA Precursor instrument. In this paper, we summarize HERA's scientific context and provide forecasts for its key science results. After reviewing the current state of the art in foreground mitigation, we use the delay-spectrum technique to motivate high-level performance requirements for the HERA instrument. Next, we present the HERA instrument design, along with the subsystem specifications that ensure that HERA meets its performance requirements. Finally, we summarize the schedule and status of the project. We conclude by suggesting that, given the realities of foreground contamination, current-generation 21 cm instruments are approaching their sensitivity limits. HERA is designed to bring both the sensitivity and the precision to deliver its primary science on the basis of proven foreground filtering techniques, while developing new subtraction techniques to unlock new capabilities. The result will be a major step toward realizing the widely recognized scientific potential of 21 cm cosmology.
hub tools
citation-role summary
citation-polarity summary
roles
background 7polarities
background 7representative citing papers
Self-interacting dark matter increases the Euler characteristic of the reionization ionization field by 60-70% for cross-sections above 2 cm2/g through changes in ionizing source populations.
New method maps 21cm cosmological structures to ~100m reflection scales for HERA-like and EDGES-like instruments, showing near-field beam calibration is required.
This work sets new upper limits on decay lifetimes and couplings for axion-like particles, dark photons, scalars, and B-L or L_i-L_j vector bosons using 511 keV line, X-ray continuum, and cosmic-ray flux observations.
Compact dark stars from asymmetric dark matter may inject energy that significantly deviates the 21-cm brightness temperature evolution from standard cosmology, offering a new probe for particle dark matter.
Bayesian GPR recovers the 21cm signal within 2σ credible intervals for most k-modes (0.06 to 1.0 h/Mpc) in SKA1-Low simulations that include realistic residual foregrounds and systematics.
Primordial magnetic fields enhance low-mass halo abundance at Cosmic Dawn, advancing Lyman-alpha coupling, X-ray heating and reionization and imprinting detectable signatures on global and fluctuating 21-cm signals observable by HERA and SKA.
Future 21-cm observations may constrain TeV-scale decaying dark matter subcomponents more tightly than CMB data for lifetimes above 10^15 s, with strongest sensitivity for neutrino decay channels due to differences in injected electromagnetic energy spectra.
Simulations show hybrid foreground mitigation (GPR + PCA combined with avoidance) recovers the HI 21cm signal within 2σ for gain calibration errors ≤1% in SKA1-Low AA* observations over 0.05-0.5 Mpc^{-1} scales.
Fisher forecasts indicate that Lyα-21cm cross-spectra with PUMA and CMB data can improve constraints on neutrino self-interaction strength G_eff by 1-2 orders of magnitude over CMB alone.
An updated linear halo bias fit calibrated on high-redshift simulations reduces systematic offsets in early-universe clustering predictions to under 1%.
citing papers explorer
-
Nearest Neighbour-Based Statistics for 21cm-Galaxy Cross-Correlations in the Epoch of Reionization
kNN CDF statistics detect 21cm-galaxy cross-correlations more effectively than two-point methods and distinguish reionization models at fixed ionized fraction even with noise and foregrounds.
-
Reionization Topology as a Probe of Self-Interacting Dark Matter
Self-interacting dark matter increases the Euler characteristic of the reionization ionization field by 60-70% for cross-sections above 2 cm2/g through changes in ionizing source populations.
-
Mapping Cosmological Signal Scales to Beam Calibration Requirements in 21cm Experiments and Implications for Near-Field Measurement
New method maps 21cm cosmological structures to ~100m reflection scales for HERA-like and EDGES-like instruments, showing near-field beam calibration is required.
-
INTEGRAL, eROSITA and Voyager Constraints on Light Bosonic Dark Matter: ALPs, Dark Photons, Scalars, $B-L$ and $L_{i}-L_{j}$ Vectors
This work sets new upper limits on decay lifetimes and couplings for axion-like particles, dark photons, scalars, and B-L or L_i-L_j vector bosons using 511 keV line, X-ray continuum, and cosmic-ray flux observations.
-
Imprints of energy injection by compact dark stars in the 21-cm signal
Compact dark stars from asymmetric dark matter may inject energy that significantly deviates the 21-cm brightness temperature evolution from standard cosmology, offering a new probe for particle dark matter.
-
Mitigating residual foregrounds and systematic errors in SKA1-Low AA* EoR observations via Bayesian Gaussian Process Regression
Bayesian GPR recovers the 21cm signal within 2σ credible intervals for most k-modes (0.06 to 1.0 h/Mpc) in SKA1-Low simulations that include realistic residual foregrounds and systematics.
-
Primordial Magnetic Fields at Cosmic Dawn: 21-cm Forecasts with HERA and SKA
Primordial magnetic fields enhance low-mass halo abundance at Cosmic Dawn, advancing Lyman-alpha coupling, X-ray heating and reionization and imprinting detectable signatures on global and fluctuating 21-cm signals observable by HERA and SKA.
-
Cosmological constraints on TeV-scale dark matter subcomponents decaying between recombination and reionisation
Future 21-cm observations may constrain TeV-scale decaying dark matter subcomponents more tightly than CMB data for lifetimes above 10^15 s, with strongest sensitivity for neutrino decay channels due to differences in injected electromagnetic energy spectra.
-
Mitigating gain calibration errors from EoR observations with SKA1-Low AA*
Simulations show hybrid foreground mitigation (GPR + PCA combined with avoidance) recovers the HI 21cm signal within 2σ for gain calibration errors ≤1% in SKA1-Low AA* observations over 0.05-0.5 Mpc^{-1} scales.
-
Neutrino self-interactions in post-reionization era: Lyman-$\alpha$, 21-cm and cross-spectra
Fisher forecasts indicate that Lyα-21cm cross-spectra with PUMA and CMB data can improve constraints on neutrino self-interaction strength G_eff by 1-2 orders of magnitude over CMB alone.
-
An Improved Fit for Linear Halo Bias at High Redshift
An updated linear halo bias fit calibrated on high-redshift simulations reduces systematic offsets in early-universe clustering predictions to under 1%.