pith. sign in

arxiv: 2607.01864 · v1 · pith:GZFWK246new · submitted 2026-07-02 · 🌌 astro-ph.CO · astro-ph.IM

meer21cm: an Analysis Pipeline and Comprehensive Toolkit for HI Intensity Mapping

Zhaoting Chen , Steven Cunnington , Daniel Tassie , Alkistis Pourtsidou , Laura Wolz , Gabriele Autieri , Matilde Barberi-Squarotti , Jos\'e Luis Bernal
show 18 more authors
Phil Bull Stefano Camera Isabella P. Carucci Brandon Engelbrecht Jos\'e Fonseca Karin Fornazier Keith Grainge Jiakang Han Wenkai Hu Melis O. Irfan Piyanat Kittiwisit Yichao Li Sefa Pamuk Mario G. Santos Marta Spinelli Jingying Wang Amadeus Witzemann Boyan Zhao (MeerKLASS Collaboration)
This is my paper

Pith reviewed 2026-07-03 06:52 UTC · model grok-4.3

classification 🌌 astro-ph.CO astro-ph.IM
keywords HI intensity mappingpower spectrum estimationforeground cleaningmock simulationmulti-tracer analysisPython packagecosmological surveys
0
0 comments X

The pith

The meer21cm Python package supplies a modular pipeline for HI intensity mapping data analysis that recovers power spectra to per-cent accuracy on simulated survey patches.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper presents meer21cm as a Python toolkit built for post-calibration analysis of single-dish HI intensity mapping surveys. It supplies modules that handle foreground cleaning, power spectrum estimation, mock generation, transfer function corrections and parameter inference while enforcing consistency with chosen survey specifications. Tests on ten simulated 750 square degree patches at 0.6 less than z less than 0.8 show the estimated power spectrum stays within one percent of the input model for wave numbers between 0.02 and 0.2 inverse megaparsecs, with offsets below half a standard deviation. The code also supports cross-correlation with overlapping galaxy catalogues. A reader would value a ready-made, survey-specific tool that reduces the effort needed to turn raw intensity maps into cosmological measurements.

Core claim

meer21cm is a survey-oriented Python package that performs the full sequence of intensity mapping analysis steps after calibration, including data ingestion, foreground removal, power spectrum computation, mock simulation and inference, while maintaining consistent treatment of observational effects; when applied to simulated MeerKLASS UHF-band patches the pipeline recovers the input power spectrum to per-cent level for k between 0.02 and 0.2 h Mpc inverse, with mock-to-model deviations no larger than 0.5 sigma.

What carries the argument

The meer21cm package, a modular Python code base that enforces survey-specific modelling of observational effects throughout foreground cleaning, power spectrum estimation and transfer function corrections.

If this is right

  • The pipeline produces power spectra whose modelling remains consistent with the exact survey geometry and analysis choices.
  • The same code base can analyse both auto-power spectra of intensity maps and cross-power spectra with galaxy catalogues.
  • Mock simulations generated inside the package can be used directly for covariance estimation and parameter inference.
  • Transfer function corrections are applied in a manner tied to the specific foreground cleaning and map-making steps.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The modular structure could allow users to swap in alternative foreground cleaning algorithms while preserving the rest of the pipeline.
  • Public release of the code lowers the barrier for groups without large simulation teams to perform intensity mapping analyses.
  • If the package were run on real data the same accuracy metric would provide a direct test of whether unmodelled systematics remain below the one-percent threshold.

Load-bearing premise

The mock simulations used for testing accurately represent the real observational effects, foregrounds, and data analysis choices specific to the survey.

What would settle it

Apply the pipeline to actual observed intensity maps from the survey and check whether the recovered power spectrum matches independent measurements or more complete end-to-end simulations at the same one-percent level.

Figures

Figures reproduced from arXiv: 2607.01864 by Alkistis Pourtsidou, Amadeus Witzemann, Boyan Zhao (MeerKLASS Collaboration), Brandon Engelbrecht, Daniel Tassie, Gabriele Autieri, Isabella P. Carucci, Jiakang Han, Jingying Wang, Jos\'e Fonseca, Jos\'e Luis Bernal, Karin Fornazier, Keith Grainge, Laura Wolz, Mario G. Santos, Marta Spinelli, Matilde Barberi-Squarotti, Melis O. Irfan, Phil Bull, Piyanat Kittiwisit, Sefa Pamuk, Stefano Camera, Steven Cunnington, Wenkai Hu, Yichao Li, Zhaoting Chen.

Figure 1
Figure 1. Figure 1: Mock map demonstrations of the effects from observational contamination. Left panel shows the “observed” map before cleaning illustrating the dominant foregrounds. The telescope beam and thermal noise have also been included in this observed map. This is then cleaned by removing 5 PCA modes to give the central panel which drops the amplitude of the fluctuations by several orders of magnitude to reveal ther… view at source ↗
Figure 2
Figure 2. Figure 2: Comparison between input and output gridded fields in comoving Cartesian space. The left panel shows the generated input mock on the simulation grid. After the mapping step, this is then interpolated onto the estimation grid (right panel) for power spectrum analysis. White space is not covered by the survey foot￾print which follows a lightone, traced by the geometry of the an￾gular and redshift coverage. T… view at source ↗
Figure 3
Figure 3. Figure 3: Validation on the accuracy of the lognormal simulation for the Hi signal and the galaxy catalogue (without any observational effects applied). Top panels show the cylindrical power spectra of the Hi auto-power, galaxy auto-power, and cross-power, respectively. For each type of the power spectrum, the left panel shows the power spectrum of the mock, the centre panel shows the input model power spectrum, and… view at source ↗
Figure 4
Figure 4. Figure 4: Validation on the accuracy of the power spectrum estimation from an end-to-end pipeline, without foreground cleaning effects. The top panels show the same types of cylindrical power spectra as [PITH_FULL_IMAGE:figures/full_fig_p009_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Validation on the accuracy of the transfer function correction from an end-to-end pipeline. The top panels show the cylindrical power spectra similar to [PITH_FULL_IMAGE:figures/full_fig_p010_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: The correlation matrix of different k-bins for the sim￾ulated power spectrum data vector, including the Hi-auto, galaxy￾auto, and cross-power. The correlation matrix is calculated from the 512 mock realisations. The Hi-auto and cross-power are the ones including foreground cleaning effects as shown in [PITH_FULL_IMAGE:figures/full_fig_p010_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: Overview of the meer21cm code structure. The main classes are denoted with solid boxes, and utility classes are denoted with dashed boxes. Solid arrows denote class inheritance, and dashed arrows denote that the class at the start of the arrow is used by the class at the end of the arrow through attributes or methods. Modules on the right provide supporting functionality. power spectra agrees with the clea… view at source ↗
read the original abstract

We present meer21cm, a comprehensive python package for cosmological data analysis of single-dish HI intensity mapping surveys. This package is simple to use, with a modularised code structure designed for interactive usage. meer21cm is designed for data analysis, with particular focus on the UHF-band observation of MeerKAT Large Area Synoptic Survey (MeerKLASS). We explicitly impose meer21cm to be survey-oriented, ensuring consistent modelling of observational effects in the clustering power spectrum with the survey specifications and data analysis choices. meer21cm covers a large range of data analysis procedures post calibration, including data read-in, foreground cleaning, power spectrum estimation, mock simulation, transfer function corrections and parameter inference. It handles both meer21cm intensity maps and overlapping galaxy catalogues, allowing for multi-tracer and cross-correlation analysis between MeerKLASS and optical galaxy surveys. Tested with a simulated survey of ten $750\,$deg$^2$ sky patches in the redshift sub-band $0.6\,{<}\,z\,{<}\,0.8$, the meer21cm pipeline achieves per-cent accuracy in the power spectrum estimation for $k \in [0.02, 0.2]\,{h{\rm Mpc}^{-1}}$, with deviations $\lesssim 0.5\sigma$ between the mock and the model power spectra, where $\sigma$ is the signal variance. The meer21cm package is publicly available and easy to install, with a comprehensive documentation website at https://meer21cm.readthedocs.io

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript presents meer21cm, a modular Python package for post-calibration analysis of single-dish HI intensity mapping surveys, focused on MeerKLASS UHF-band data. It implements data ingestion, foreground cleaning, power spectrum estimation, mock generation, transfer function corrections, and parameter inference, with support for cross-correlations against galaxy catalogs. The central claim is that tests on ten simulated 750 deg² patches at 0.6 < z < 0.8 recover the input power spectrum to per-cent accuracy for k ∈ [0.02, 0.2] h Mpc^{-1}, with mock-model deviations ≲ 0.5σ.

Significance. If the reported accuracy is robust, the package supplies a publicly documented, survey-specific toolkit that could standardize analysis choices for MeerKLASS and comparable HI IM experiments, reducing inconsistencies in foreground treatment and transfer-function modeling while enabling multi-tracer work. The open-source release and documentation website constitute concrete contributions to the field.

major comments (2)
  1. [Abstract] Abstract and validation section: the per-cent accuracy claim for k ∈ [0.02, 0.2] h Mpc^{-1} is demonstrated exclusively on the described mock survey; the manuscript must explicitly document how UHF-band beam convolution, residual foregrounds after cleaning, RFI flagging, and calibration transfer functions are realized in the mocks, because these choices directly determine whether the reported ≲ 0.5σ deviations are representative of real MeerKLASS data.
  2. [Validation] Validation tests: the manuscript should report at least one cross-check of the pipeline against an independent code or against a second, independently generated mock suite that uses different foreground or beam models, to quantify the sensitivity of the accuracy result to simulation assumptions.
minor comments (2)
  1. [Abstract] The abstract states 'per-cent accuracy' without quoting the precise metric (e.g., fractional bias or χ² per degree of freedom); a quantitative definition should appear in the abstract or first paragraph of the validation section.
  2. [Figures] Figure captions for the power-spectrum comparison plots should state the exact number of modes per k-bin and the precise definition of σ used in the deviation metric.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their positive evaluation and constructive suggestions. We address the two major comments below and will revise the manuscript to improve clarity on the mock generation and validation approach.

read point-by-point responses

  1. Referee: [Abstract] Abstract and validation section: the per-cent accuracy claim for k ∈ [0.02, 0.2] h Mpc^{-1} is demonstrated exclusively on the described mock survey; the manuscript must explicitly document how UHF-band beam convolution, residual foregrounds after cleaning, RFI flagging, and calibration transfer functions are realized in the mocks, because these choices directly determine whether the reported ≲ 0.5σ deviations are representative of real MeerKLASS data.

    Authors: We agree that explicit documentation of these mock ingredients is necessary for readers to judge how representative the reported accuracy is. Section 4 of the manuscript already outlines the mock generation procedure, but we will expand it with a dedicated subsection that details the precise implementation of UHF-band beam convolution (including the model and frequency dependence), the residual foreground levels after cleaning, the RFI flagging mask application, and the calibration transfer function. These additions will be accompanied by references to the specific simulation parameters used, allowing direct assessment against real MeerKLASS data characteristics. revision: yes

  2. Referee: [Validation] Validation tests: the manuscript should report at least one cross-check of the pipeline against an independent code or against a second, independently generated mock suite that uses different foreground or beam models, to quantify the sensitivity of the accuracy result to simulation assumptions.

    Authors: We recognize the benefit of an independent cross-validation to test sensitivity to simulation assumptions. The current validation uses a single, internally consistent mock suite that matches the survey specifications and analysis choices described in the paper. Generating a fully independent second mock suite with alternate foreground or beam models would require substantial new simulation effort beyond the scope of the present work. In the revision we will add a limited cross-check by comparing the power-spectrum estimation module against an alternative public estimator on a subset of the existing mocks, and we will explicitly state the limitations of the validation with respect to model variations. revision: partial

Circularity Check

0 steps flagged

No circularity: validation uses independent mocks on a software toolkit

full rationale

The paper presents meer21cm as a modular Python pipeline for post-calibration analysis of MeerKLASS HI intensity maps, including foreground cleaning, power spectrum estimation, transfer functions, and multi-tracer cross-correlations. Its central claim of per-cent accuracy (deviations ≲0.5σ for k ∈ [0.02, 0.2] h Mpc^{-1}) is obtained by applying the pipeline to independently generated mock surveys of ten 750 deg² patches at 0.6 < z < 0.8; the reported match is between the pipeline output on those mocks and the input model power spectra, with no equations or parameters defined in terms of the target accuracy metric itself. No self-definitional loops, fitted inputs renamed as predictions, or load-bearing self-citations appear in the derivation chain. The package is self-contained against external benchmarks once the mocks are accepted as given, satisfying the default expectation of no significant circularity.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

The work relies on standard cosmological modeling assumptions and Python libraries from prior literature; no new free parameters, axioms, or invented entities are introduced in the abstract description.

pith-pipeline@v0.9.1-grok · 5932 in / 1290 out tokens · 40013 ms · 2026-07-03T06:52:36.303229+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

95 extracted references · 92 canonical work pages · 42 internal anchors

  1. [1]

    , keywords =

    H I intensity mapping with MeerKAT: power spectrum detection in cross-correlation with WiggleZ galaxies. , keywords =. doi:10.1093/mnras/stac3060 , archivePrefix =. 2206.01579 , primaryClass =

    work page doi:10.1093/mnras/stac3060

  2. [2]

    21-cm Tomography of the Intergalactic Medium at High Redshift

    21 Centimeter Tomography of the Intergalactic Medium at High Redshift. , keywords =. doi:10.1086/303549 , archivePrefix =. astro-ph/9608010 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1086/303549

  3. [3]

    Using HI to probe large scale structures at z ~ 3

    Using HI to probe large scale structures at z 3. Journal of Astrophysics and Astronomy , keywords =. doi:10.1007/BF02933588 , archivePrefix =. astro-ph/0003200 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1007/bf02933588

  4. [4]

    L., McClure-Griffiths, N

    Neutral hydrogen surveys for high-redshift galaxy clusters and protoclusters. , keywords =. doi:10.1111/j.1365-2966.2004.08416.x , archivePrefix =. astro-ph/0401340 , primaryClass =

    work page doi:10.1111/j.1365-2966.2004.08416.x 2004

  5. [5]

    Baryon Acoustic Oscillation Intensity Mapping as a Test of Dark Energy

    Baryon Acoustic Oscillation Intensity Mapping of Dark Energy. , keywords =. doi:10.1103/PhysRevLett.100.091303 , archivePrefix =. 0709.3672 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1103/physrevlett.100.091303

  6. [6]

    J., Johansson, P

    The 21-cm power spectrum after reionization. , keywords =. doi:10.1111/j.1365-2966.2009.15019.x , archivePrefix =. 0808.2323 , primaryClass =

    work page doi:10.1111/j.1365-2966.2009.15019.x 2009

  7. [7]

    , year = 2010, month = jul, volume =

    An intensity map of hydrogen 21-cm emission at redshift z -0.5ex 0.8. , year = 2010, month = jul, volume =. doi:10.1038/nature09187 , adsurl =

    work page doi:10.1038/nature09187 2010

  8. [8]

    HI intensity mapping : a single dish approach

    H I intensity mapping: a single dish approach. , keywords =. doi:10.1093/mnras/stt1082 , archivePrefix =. 1209.0343 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stt1082

  9. [9]

    , keywords =

    Cosmology with Phase 1 of the Square Kilometre Array Red Book 2018: Technical specifications and performance forecasts. , keywords =. doi:10.1017/pasa.2019.51 , archivePrefix =. 1811.02743 , primaryClass =

    work page doi:10.1017/pasa.2019.51 2018

  10. [10]

    Measurement of 21 cm brightness fluctuations at z ~ 0.8 in cross-correlation

    Measurement of 21 cm Brightness Fluctuations at z -0.5ex 0.8 in Cross-correlation. , keywords =. doi:10.1088/2041-8205/763/1/L20 , archivePrefix =. 1208.0331 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/2041-8205/763/1/l20 2041

  11. [11]

    Determination of z~0.8 neutral hydrogen fluctuations using the 21 cm intensity mapping auto-correlation

    Determination of z -0.5ex 0.8 neutral hydrogen fluctuations using the 21cm intensity mapping autocorrelation. , keywords =. doi:10.1093/mnrasl/slt074 , archivePrefix =. 1304.3712 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnrasl/slt074

  12. [12]

    Lack of clustering in low-redshift 21-cm intensity maps cross-correlated with 2dF galaxy densities

    Low-amplitude clustering in low-redshift 21-cm intensity maps cross-correlated with 2dF galaxy densities. , keywords =. doi:10.1093/mnras/sty346 , archivePrefix =. 1710.00424 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/sty346

  13. [13]

    , keywords =

    H I constraints from the cross-correlation of eBOSS galaxies and Green Bank Telescope intensity maps. , keywords =. doi:10.1093/mnras/stab3621 , archivePrefix =. 2102.04946 , primaryClass =

    work page doi:10.1093/mnras/stab3621

  14. [14]

    , keywords =

    Detection of Cosmological 21 cm Emission with the Canadian Hydrogen Intensity Mapping Experiment. , keywords =. doi:10.3847/1538-4357/acb13f , archivePrefix =. 2202.01242 , primaryClass =

    work page doi:10.3847/1538-4357/acb13f

  15. [15]

    , keywords =

    Hydrogen intensity mapping with MeerKAT: Preserving cosmological signal by optimising contaminant separation. , keywords =. doi:10.1051/0004-6361/202453461 , archivePrefix =. 2412.06750 , primaryClass =

    work page doi:10.1051/0004-6361/202453461

  16. [16]

    , keywords =

    MeerKLASS L-band deep-field intensity maps: entering the H I dominated regime. , keywords =. doi:10.1093/mnras/staf195 , archivePrefix =. 2407.21626 , primaryClass =

    work page doi:10.1093/mnras/staf195

  17. [17]

    MeerKLASS: MeerKAT Large Area Synoptic Survey

    A Large Sky Survey with MeerKAT. MeerKAT Science: On the Pathway to the SKA , year = 2016, month = jan, eid =. doi:10.22323/1.277.0032 , archivePrefix =. 1709.06099 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.22323/1.277.0032 2016

  18. [18]

    The effect of foreground subtraction on cosmological measurements from Intensity Mapping

    The effect of foreground subtraction on cosmological measurements from intensity mapping. , keywords =. doi:10.1093/mnras/stu792 , archivePrefix =. 1310.8144 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stu792

  19. [19]

    Bayesian semi-blind component separation for foreground removal in interferometric 21-cm observations

    Bayesian Semi-blind Component Separation for Foreground Removal in Interferometric 21 cm Observations. , keywords =. doi:10.3847/0067-0049/222/1/3 , archivePrefix =. 1505.04146 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.3847/0067-0049/222/1/3

  20. [20]

    Extracting HI cosmological signal with Generalized Needlet Internal Linear Combination

    Extracting H I cosmological signal with generalized needlet internal linear combination. , keywords =. doi:10.1093/mnras/stv2884 , archivePrefix =. 1509.00742 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stv2884

  21. [21]

    21cm Signal Recovery via the Robust Principle Component Analysis

    21 cm Signal Recovery via Robust Principal Component Analysis. , keywords =. doi:10.3847/1538-3881/aaef3b , archivePrefix =. 1801.04082 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.3847/1538-3881/aaef3b

  22. [22]

    , keywords =

    Cleaning foregrounds from single-dish 21 cm intensity maps with Kernel principal component analysis. , keywords =. doi:10.1093/mnras/stab2855 , archivePrefix =. 2107.02267 , primaryClass =

    work page doi:10.1093/mnras/stab2855

  23. [23]

    , keywords =

    Recovery of 21-cm intensity maps with sparse component separation. , keywords =. doi:10.1093/mnras/staa2854 , archivePrefix =. 2006.05996 , primaryClass =

    work page doi:10.1093/mnras/staa2854 2006

  24. [24]

    Calibration Requirements for Detecting the 21 cm Epoch of Reionization Power Spectrum and Implications for the SKA

    Calibration requirements for detecting the 21 cm epoch of reionization power spectrum and implications for the SKA. , keywords =. doi:10.1093/mnras/stw1380 , archivePrefix =. 1603.00607 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stw1380

  25. [25]

    , keywords =

    Field sources near the southern-sky calibrator PKS B1934-638: effect on spectral line observations with SKA-MID and its precursors. , keywords =. doi:10.1093/mnras/staa941 , archivePrefix =. 2004.00454 , primaryClass =

    work page doi:10.1093/mnras/staa941 2004

  26. [26]

    Fast simulations for intensity mapping experiments

    Fast simulations for intensity mapping experiments. , keywords =. doi:10.1093/mnras/stu1666 , archivePrefix =. 1405.1751 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stu1666

  27. [27]

    , keywords =

    21-cm foregrounds and polarization leakage: cleaning and mitigation strategies. , keywords =. doi:10.1093/mnras/stab856 , archivePrefix =. 2010.02907 , primaryClass =

    work page doi:10.1093/mnras/stab856 2010

  28. [28]

    , keywords =

    H I intensity mapping with MeerKAT: primary beam effects on foreground cleaning. , keywords =. doi:10.1093/mnras/stab1688 , archivePrefix =. 2011.10815 , primaryClass =

    work page doi:10.1093/mnras/stab1688 2011

  29. [29]

    Characterization from Simulations and Power Spectrum Implications

    Primary Beam Chromaticity in HIRAX: I. Characterization from Simulations and Power Spectrum Implications. arXiv e-prints , keywords =. doi:10.48550/arXiv.2412.09527 , archivePrefix =. 2412.09527 , primaryClass =

    work page doi:10.48550/arxiv.2412.09527

  30. [30]

    , keywords =

    Emission-line Stacking of 21 cm Intensity Maps with MeerKLASS: Inference Pipeline and Application to the L-band Deep-field Data. , keywords =. doi:10.3847/1538-4365/add897 , archivePrefix =. 2504.03908 , primaryClass =

    work page doi:10.3847/1538-4365/add897

  31. [31]

    Interpreting the unresolved intensity of cosmologically redshifted line radiation

    Interpreting the Unresolved Intensity of Cosmologically Redshifted Line Radiation. , keywords =. doi:10.1088/0004-637X/815/1/51 , archivePrefix =. 1504.07527 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/0004-637x/815/1/51

  32. [32]

    Late-time cosmology with 21cm intensity mapping experiments

    Late-time Cosmology with 21 cm Intensity Mapping Experiments. , keywords =. doi:10.1088/0004-637X/803/1/21 , archivePrefix =. 1405.1452 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/0004-637x/803/1/21

  33. [33]

    , keywords =

    Multipole expansion for H I intensity mapping experiments: simulations and modelling. , keywords =. doi:10.1093/mnras/staa1524 , archivePrefix =. 2002.05626 , primaryClass =

    work page doi:10.1093/mnras/staa1524 2002

  34. [34]

    , keywords =

    A quadratic estimator view of the transfer function correction in intensity mapping surveys. , keywords =. doi:10.1093/mnrasl/slaf058 , archivePrefix =. 2504.13070 , primaryClass =

    work page doi:10.1093/mnrasl/slaf058

  35. [35]

    , keywords =

    Accurate Fourier-space statistics for line intensity mapping: Cartesian grid sampling without aliased power. , keywords =. doi:10.1093/mnras/stae333 , archivePrefix =. 2312.07289 , primaryClass =

    work page doi:10.1093/mnras/stae333

  36. [36]

    , keywords =

    Clustering in real space and in redshift space. , keywords =. doi:10.1093/mnras/227.1.1 , adsurl =

    work page doi:10.1093/mnras/227.1.1

  37. [37]

    Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe

    Cosmology at low frequencies: The 21 cm transition and the high-redshift Universe. , keywords =. doi:10.1016/j.physrep.2006.08.002 , archivePrefix =. astro-ph/0608032 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1016/j.physrep.2006.08.002 2006

  38. [38]

    Hellwig, Helmut and Vessot, Robert F. C. and Levine, Martin W. and Zitzewitz, Paul W. and Allan, David W. and Glaze, David J. , journal=. Measurement of the Unperturbed Hydrogen Hyperfine Transition Frequency , year=

  39. [39]

    , keywords =

    Power spectrum modelling of galaxy and radio intensity maps including observational effects. , keywords =. doi:10.1093/mnras/stz2145 , archivePrefix =. 1902.07439 , primaryClass =

    work page doi:10.1093/mnras/stz2145 1902

  40. [40]

    , keywords =

    The foreground transfer function for H I intensity mapping signal reconstruction: MeerKLASS and precision cosmology applications. , keywords =. doi:10.1093/mnras/stad1567 , archivePrefix =. 2302.07034 , primaryClass =

    work page doi:10.1093/mnras/stad1567

  41. [41]

    DESI 2024 III: Baryon Acoustic Oscillations from Galaxies and Quasars

    DESI 2024 III: baryon acoustic oscillations from galaxies and quasars. , keywords =. doi:10.1088/1475-7516/2025/04/012 , archivePrefix =. 2404.03000 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/1475-7516/2025/04/012 2024

  42. [42]

    Planck 2018 results. VI. Cosmological parameters. , keywords =. doi:10.1051/0004-6361/201833910 , archivePrefix =. 1807.06209 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1051/0004-6361/201833910 2018

  43. [43]

    I., Schawinski, K., Kaviraj, S., et al

    The 6dF Galaxy Survey: baryon acoustic oscillations and the local Hubble constant. , keywords =. doi:10.1111/j.1365-2966.2011.19250.x , archivePrefix =. 1106.3366 , primaryClass =

    work page doi:10.1111/j.1365-2966.2011.19250.x 2011

  44. [44]

    The Python Sky Model: software for simulating the Galactic microwave sky

    The Python Sky Model: software for simulating the Galactic microwave sky. , keywords =. doi:10.1093/mnras/stx949 , archivePrefix =. 1608.02841 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stx949

  45. [45]

    The Journal of Open Source Software , keywords =

    The Python Sky Model 3 software. The Journal of Open Source Software , keywords =. doi:10.21105/joss.03783 , archivePrefix =. 2108.01444 , primaryClass =

    work page doi:10.21105/joss.03783

  46. [46]

    , keywords =

    Full-sky Models of Galactic Microwave Emission and Polarization at Subarcminute Scales for the Python Sky Model. , keywords =. doi:10.3847/1538-4357/adf212 , archivePrefix =. 2502.20452 , primaryClass =

    work page doi:10.3847/1538-4357/adf212

  47. [47]

    , keywords =

    An evolution free test for non-zero cosmological constant. , keywords =. doi:10.1038/281358a0 , adsurl =

    work page doi:10.1038/281358a0

  48. [48]

    , keywords =

    HI intensity mapping with the MIGHTEE Survey: first results of the HI power spectrum. , keywords =. doi:10.1093/mnras/staf975 , archivePrefix =. 2501.17564 , primaryClass =

    work page doi:10.1093/mnras/staf975

  49. [49]

    Why your model parameter confidences might be too optimistic -- unbiased estimation of the inverse covariance matrix

    Why your model parameter confidences might be too optimistic. Unbiased estimation of the inverse covariance matrix. , keywords =. doi:10.1051/0004-6361:20066170 , archivePrefix =. astro-ph/0608064 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1051/0004-6361:20066170

  50. [50]

    The Clustering of Galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Including covariance matrix errors

    The clustering of Galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: including covariance matrix errors. , keywords =. doi:10.1093/mnras/stu112 , archivePrefix =. 1312.4841 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stu112

  51. [51]

    , keywords =

    Analytical and EZmock covariance validation for the DESI 2024 results. , keywords =. doi:10.1088/1475-7516/2025/04/055 , archivePrefix =. 2411.12027 , primaryClass =

    work page doi:10.1088/1475-7516/2025/04/055 2024

  52. [52]

    Generating Log-normal Mock Catalog of Galaxies in Redshift Space

    Generating log-normal mock catalog of galaxies in redshift space. , keywords =. doi:10.1088/1475-7516/2017/10/003 , archivePrefix =. 1706.09195 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/1475-7516/2017/10/003 2017

  53. [53]

    An accurate low-redshift measurement of the cosmic neutral hydrogen density

    An accurate low-redshift measurement of the cosmic neutral hydrogen density. , keywords =. doi:10.1093/mnras/stz2038 , archivePrefix =. 1907.10375 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stz2038 1907

  54. [54]

    , keywords =

    The simple way to measure evolving dark energy without prior-volume effects. , keywords =. doi:10.1088/1475-7516/2026/04/030 , archivePrefix =. 2509.09562 , primaryClass =

    work page doi:10.1088/1475-7516/2026/04/030 2026

  55. [55]

    The Effective Field Theory of Cosmological Large Scale Structures

    The effective field theory of cosmological large scale structures. Journal of High Energy Physics , keywords =. doi:10.1007/JHEP09(2012)082 , archivePrefix =. 1206.2926 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1007/jhep09(2012)082 2012

  56. [56]

    The Effective Field Theory of Dark Matter and Structure Formation: Semi-Analytical Results

    Effective field theory of dark matter and structure formation: Semianalytical results. , keywords =. doi:10.1103/PhysRevD.89.043521 , archivePrefix =. 1208.0839 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1103/physrevd.89.043521

  57. [57]

    , keywords =

    Modified gravity and massive neutrinos: constraints from the full shape analysis of BOSS galaxies and forecasts for Stage IV surveys. , keywords =. doi:10.1088/1475-7516/2023/12/025 , archivePrefix =. 2306.09275 , primaryClass =

    work page doi:10.1088/1475-7516/2023/12/025 2023

  58. [58]

    , keywords =

    Cosmology with the EFTofLSS and BOSS: dark energy constraints and a note on priors. , keywords =. doi:10.1088/1475-7516/2023/01/028 , archivePrefix =. 2207.14784 , primaryClass =

    work page doi:10.1088/1475-7516/2023/01/028 2023

  59. [59]

    Detecting redshift space distortions and probing the growth rate of cosmic structure with 21cm intensity maps from MeerKLASS

    Tassie, Daniel and others. Detecting redshift space distortions and probing the growth rate of cosmic structure with 21cm intensity maps from MeerKLASS. -. in prep

  60. [60]

    , keywords =

    NAUTILUS: boosting Bayesian importance nested sampling with deep learning. , keywords =. doi:10.1093/mnras/stad2441 , archivePrefix =. 2306.16923 , primaryClass =

    work page doi:10.1093/mnras/stad2441

  61. [61]

    Correcting for the alias effect when measuring the power spectrum using FFT

    Correcting for the Alias Effect When Measuring the Power Spectrum Using a Fast Fourier Transform. , keywords =. doi:10.1086/427087 , archivePrefix =. astro-ph/0409240 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1086/427087

  62. [62]

    An improved source-subtracted and destriped 408 MHz all-sky map

    An improved source-subtracted and destriped 408-MHz all-sky map. , keywords =. doi:10.1093/mnras/stv1274 , archivePrefix =. 1411.3628 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stv1274

  63. [63]

    An Improved Model of Diffuse Galactic Radio Emission from 10 MHz to 5 THz

    An improved model of diffuse galactic radio emission from 10 MHz to 5 THz. , keywords =. doi:10.1093/mnras/stw2525 , archivePrefix =. 1605.04920 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stw2525

  64. [64]

    , keywords =

    H I intensity mapping with MeerKAT: calibration pipeline for multidish autocorrelation observations. , keywords =. doi:10.1093/mnras/stab1365 , archivePrefix =. 2011.13789 , primaryClass =

    work page doi:10.1093/mnras/stab1365 2011

  65. [65]

    Efficient Computation of CMB anisotropies in closed FRW models

    Efficient Computation of Cosmic Microwave Background Anisotropies in Closed Friedmann-Robertson-Walker Models. , keywords =. doi:10.1086/309179 , archivePrefix =. astro-ph/9911177 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1086/309179

  66. [66]

    The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package

    The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package. , keywords =. doi:10.3847/1538-4357/ac7c74 , archivePrefix =. 2206.14220 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.3847/1538-4357/ac7c74

  67. [67]

    , keywords =

    The bacco simulation project: bacco hybrid Lagrangian bias expansion model in redshift space. , keywords =. doi:10.1093/mnras/stad368 , archivePrefix =. 2207.06437 , primaryClass =

    work page doi:10.1093/mnras/stad368

  68. [68]

    A direct detection of neutral hydrogen intensity mapping on Mpc scales at $z\approx 0.32$ and $z\approx 0.44$

    A first detection of neutral hydrogen intensity mapping on Mpc scales at z 0.32 and z 0.44. arXiv e-prints , keywords =. doi:10.48550/arXiv.2301.11943 , archivePrefix =. 2301.11943 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.2301.11943

  69. [69]

    arXiv e-prints , keywords =

    Detection of the Cosmological 21 cm Signal in Auto-correlation at z -0.5ex 1 with the Canadian Hydrogen Intensity Mapping Experiment. arXiv e-prints , keywords =. doi:10.48550/arXiv.2511.19620 , archivePrefix =. 2511.19620 , primaryClass =

    work page doi:10.48550/arxiv.2511.19620

  70. [70]

    , keywords =

    Revealing cosmological fluctuations in 21 cm intensity maps with MeerKLASS: from maps to power spectra. , keywords =. doi:10.1007/s10509-026-04547-7 , archivePrefix =. 2510.27549 , primaryClass =

    work page doi:10.1007/s10509-026-04547-7

  71. [71]

    A multitracer analysis for the eBOSS galaxy sample based on the effective field theory of large-scale structure

    A multitracer analysis for the eBOSS galaxy sample based on the effective field theory of large-scale structure. , keywords =. doi:10.1093/mnras/stae1452 , archivePrefix =. 2308.06206 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/stae1452

  72. [72]

    , keywords =

    The effective field theory of large-scale structure and multi-tracer. , keywords =. doi:10.1088/1475-7516/2022/04/021 , archivePrefix =. 2108.11363 , primaryClass =

    work page doi:10.1088/1475-7516/2022/04/021 2022

  73. [73]

    A Measurement of the Quadrupole Power Spectrum in the Clustering of the 2dF QSO Survey

    A Measurement of the Quadrupole Power Spectrum in the Clustering of the 2dF QSO Survey. , keywords =. doi:10.1093/pasj/58.1.93 , archivePrefix =. astro-ph/0505115 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/pasj/58.1.93

  74. [74]

    , keywords =

    Semi-analytical covariance matrices for two-point correlation function for DESI 2024 data. , keywords =. doi:10.1088/1475-7516/2025/01/145 , archivePrefix =. 2404.03007 , primaryClass =

    work page doi:10.1088/1475-7516/2025/01/145 2024

  75. [75]

    Cobaya: Code for Bayesian Analysis of hierarchical physical models

    Cobaya: code for Bayesian analysis of hierarchical physical models. , keywords =. doi:10.1088/1475-7516/2021/05/057 , archivePrefix =. 2005.05290 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/1475-7516/2021/05/057 2021

  76. [76]

    2010, MNRAS, 405, 933, doi: 10.1111/j.1365-2966.2010.16536.x

    The WiggleZ Dark Energy Survey: the selection function and z = 0.6 galaxy power spectrum. , keywords =. doi:10.1111/j.1365-2966.2010.16747.x , archivePrefix =. 1003.5721 , primaryClass =

    work page doi:10.1111/j.1365-2966.2010.16747.x 2010

  77. [77]

    , keywords =

    H I intensity mapping with MeerKAT: 1/f noise analysis. , keywords =. doi:10.1093/mnras/staa3856 , archivePrefix =. 2007.01767 , primaryClass =

    work page doi:10.1093/mnras/staa3856 2007

  78. [78]

    , keywords =

    Mitigating the effect of 1/f noise on the detection of the H I intensity mapping power spectrum from single-dish measurements. , keywords =. doi:10.1093/mnras/stad3457 , archivePrefix =. 2302.02683 , primaryClass =

    work page doi:10.1093/mnras/stad3457

  79. [79]

    arXiv e-prints , keywords =

    Measurements of the HI intensity mapping power spectrum at low redshifts with MIGHTEE data: comparison with detected HI galaxies. arXiv e-prints , keywords =. doi:10.48550/arXiv.2602.23055 , archivePrefix =. 2602.23055 , primaryClass =

    work page doi:10.48550/arxiv.2602.23055

  80. [80]

    Fingers of God

    A critique of Rees's theory of primordial gravitational radiation. , keywords =. doi:10.1093/mnras/156.1.1P , archivePrefix =. 0810.3908 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1093/mnras/156.1.1p

Showing first 80 references.