# ASTR 476 Reference and Provenance Log

## Provenance levels

- Level 1: source files fetched and hashed during this production session.
- Level 2: standard published result transcribed from cited literature; paper content was not freshly fetched in this session and requires human spot-check.
- Level 3: model-generated or schematic teaching material, never represented as observational data.

## Level 1: live-verified data

- Pantheon+SH0ES table and statistical-plus-systematic covariance: official public release repository, `Pantheon+_Data/4_DISTANCES_AND_COVAR/Pantheon+SH0ES.dat` and `Pantheon+SH0ES_STAT+SYS.cov`, https://github.com/PantheonPlusSH0ES/DataRelease . Fetched 2026-09-25; SHA-256 digests, row count, selection rule, covariance size, and excerpt file names are in `data/pantheonplus-subset-provenance.json`. The 18-row excerpt is selected nearest fixed target redshifts from unique non-calibrator rows with zHD>=0.023; source row order is retained for covariance indexing. The source covariance is rounded to 8 decimals; paired values differed by at most 3e-8 and were averaged only after a 5e-8 absolute tolerance check. Its matched 18x18 block is included.
- The subset is redshift-stratified, not representative. It supports plotting and a conditional intercept demonstration only. It does not reproduce Pantheon+ parameter constraints; the full 1701x1701 covariance is not bundled. MU_SH0ES_ERR_DIAG is plotting-only; inference must use the matched covariance.

## Level 2: published summaries, not re-fetched from the papers this session

- Planck Collaboration VI (2020), *Planck 2018 results. VI. Cosmological parameters*, A&A 641, A6, https://doi.org/10.1051/0004-6361/201833910 . TT,TE,EE+lowE, flat-LCDM abstract summaries H0=67.4±0.5 km s-1 Mpc-1, Omega_m=0.315±0.007, and 100 theta_star=1.0411±0.0003. Official Planck Legacy Archive landing page was verified, but requested binned TT returned an extraction failure and TE returned HTTP 401. No bandpowers are included or claimed live-verified.
- Brout et al. (2022), *The Pantheon+ Analysis: Cosmological Constraints*, ApJ 938, 110, https://doi.org/10.3847/1538-4357/ac8e04 . Published abstract summaries Omega_M=0.334±0.018 for SNe-only flat LCDM and w0=-0.90±0.14 for SNe-only flat w0CDM. The course does not treat these as constraints from its excerpt.
- Alam et al. (2017), *The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological analysis of the DR12 galaxy sample*, MNRAS 470, 2617, https://doi.org/10.1093/mnras/stx721. Published D_V r_d,fid/r_d summary values at z=0.38, 0.51, 0.61 and errors are encoded in `data/published-summary-measurements.csv`; see paper section 8.2 equations (21)-(23). Values are literature summaries, not raw clustering data.
- Dark Energy Survey Collaboration (2022), *Dark Energy Survey Year 3 results: Cosmological constraints from galaxy clustering and weak lensing*, Phys. Rev. D 105, 023520, https://doi.org/10.1103/PhysRevD.105.023520. Published flat-LCDM summaries S8=0.776±0.017 and Omega_m=0.339(+0.032,-0.031), plus the wCDM summary in the CSV. No shear vector, likelihood, or covariance is bundled.

## Level 3: model and schematic outputs

- Flat matter-plus-Lambda distance calculations use H0=67.4 km s-1 Mpc-1 and Omega_m=0.315. Radiation is excluded; the Astropy cross-check explicitly sets Tcmb0=0 K to match. Do not apply this late-time model to recombination.
- `data/computed-reference-results.json`, `data/published-summary-measurements.csv`, and `data/pantheonplus-gls-intercept.json` are generated by `src/astr476_computations.py` and `src/build_astr476_package.py`. The excerpt intercept is conditional on fixed model shape and must not be described as a survey-level cosmological result.
- Lecture diagrams that are theoretical, synthetic, or schematic are labeled in their captions. In particular, the CMB oscillation curve is not Planck bandpower data, the parameter ellipse is synthetic, and error-budget bar weights are illustrative only.

## Software

Exact package versions and the Python version are in `requirements.txt`. Source documentation links are cited above; code/API versions are pinned for reproducibility. Verify papers and policies before local instructional use.