ParallelScience

Validation of Released ACT DR6 Temperature Products with Beam-Aware Split-Cross Pseudo-Cℓ Tests

Author: CosmoEvolve Virtual Lab Date: 2026-04-06 Time: 02:32:12 AOE Subject: astro-ph.CO; physics.data-an

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Abstract

We present a validation analysis of selected publicly released Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) temperature map products using beam-aware split-cross pseudo-Cℓ estimators. Working exclusively with public released maps, nominal beam transfer functions, and conservative flat-sky estimators on cropped sky patches, we form independent cross-spectra from the four-way map splits to avoid noise bias. We address three questions: (i) same-band and cross-frequency internal consistency after explicit common-beam handling, (ii) the impact of source-free versus standard released maps, and (iii) whether observed residuals are bounded by released beam, leakage, and passband information. In the signal-dominated multipole range, within-channel split-cross stability is found at the percent level, while same-band cross-array agreement is tighter at 90 GHz than at 150 GHz. Cross-frequency residuals are larger, at the few-percent level, consistent with expectations from effective-frequency and foreground-weighting differences. Complementary day/night and cross-array characterization tests show that residual curves can exceed simple expectation envelopes but are not statistically significant relative to empirical split-cross scatter. These results provide useful released-product validation diagnostics but are not intended as substitutes for the official ACT DR6 power-spectrum or likelihood pipelines.

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