REVIEW 6 cited by
A Detection of Cosmological 21 cm Emission from CHIME in Cross-correlation with eBOSS Measurements of the Lyman-$\alpha$ Forest
Not yet reviewed by Pith; the record is open.
This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.
SPECIMEN: schema-true, not a live event
T0 review · schema-true
One-sentence machine reading of the paper's core claim.
pith:XXXXXXXX · record.json · timestamp
abstract
We report the detection of 21 cm emission at an average redshift $\bar{z} = 2.3$ in the cross-correlation of data from the Canadian Hydrogen Intensity Mapping Experiment (CHIME) with measurements of the Lyman-$\alpha$ forest from eBOSS. Data collected by CHIME over 88 days in the $400-500$~MHz frequency band ($1.8 < z < 2.5$) are formed into maps of the sky and high-pass delay filtered to suppress the foreground power, corresponding to removing cosmological scales with $k_\parallel \lesssim 0.13\ \text{Mpc}^{-1}$ at the average redshift. Line-of-sight spectra to the eBOSS background quasar locations are extracted from the CHIME maps and combined with the Lyman-$\alpha$ forest flux transmission spectra to estimate the 21 cm-Lyman-$\alpha$ cross-correlation function. Fitting a simulation-derived template function to this measurement results in a $9\sigma$ detection significance. The coherent accumulation of the signal through cross-correlation is sufficient to enable a detection despite excess variance from foreground residuals $\sim6-10$ times brighter than the expected thermal noise level in the correlation function. These results are the highest-redshift measurement of \tcm emission to date, and set the stage for future 21 cm intensity mapping analyses at $z>1.8$.
Forward citations
Cited by 6 Pith papers
-
Spectral Data-cube Cleaning for CCAT Deep Spectroscopic Survey. I. Effect of correlated noise and filtering on the power spectrum
The EoR-Spec Filter-and-Bin pipeline suppresses atmospheric 1/f noise by about four orders of magnitude and recovers the [CII]+CO power spectrum above k ~ 0.1 Mpc^-1, but suppresses large-scale modes below 20% transfe...
-
Testing the Isotropy of the Universe with the CHIME/FRB Catalog I
A 536-burst CHIME FRB sample shows no statistically significant directional anisotropy, though the test's constraining power is limited.
-
Simulation-Based Priors for HI Bias from Halo Occupation Physics
A conditional normalizing flow learned from two simulation suites maps HI halo-occupation parameters to EFT bias parameters, producing correlated non-Gaussian priors that are much tighter than flat priors for 21 cm analyses.
-
Tracing Large-Scale Structure Morphology with Multiwavelength Line Intensity Maps
CO(1-0) line intensity maps trace the cosmic web's filaments and sheets more strongly than HI 21-cm maps, and SKA2-Mid could recover this structure at z~1.4.
-
Mitigating antenna gain errors with HyFoReS in CHIME simulations
HyFoReS reduces simulated gain-induced foreground leakage in 21-cm power spectra by up to 1000 times, reaching the thermal noise level only for bandpass errors below about 1e-4.
-
Cosmology with HI Intensity Mapping
SKAO HI intensity mapping forecasts yield competitive LambdaCDM constraints (e.g. H0 to ~0.3 km/s/Mpc optimistic) via power spectrum, BAO, bispectrum and stacking, complementary to CMB and optical surveys.
Discussion (0). Continue with ORCID to comment.