MeerKLASS L-band deep-field intensity maps: entering the H I dominated regime

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dc.creatorBarberi-Squarotti, M
dc.creatorBernal, JL
dc.creatorBull, P
dc.creatorCamera, S
dc.creatorCarucci, IP
dc.creatorChen, Z
dc.creatorCunnington, S
dc.creatorEngelbrecht, BN
dc.creatorFonseca, J
dc.creatorGrainge, K
dc.creatorIrfan, MO
dc.creatorLi, Y
dc.creatorMazumder, A
dc.creatorPaul, S
dc.creatorPourtsidou, A
dc.creatorSantos, MG
dc.creatorSpinelli, M
dc.creatorWang, J
dc.creatorWitzemann, A
dc.creatorWolz, L
dc.date2025-06-25T15:21:26Z
dc.date2025-02-17
dc.date2024-08-06
dc.date2025-06-25T15:21:26Z
dc.date.accessioned2026-08-03T03:59:22Z
dc.description<jats:title>ABSTRACT</jats:title> <jats:p>We present results from MeerKAT single-dish H i intensity maps, the final observations to be performed in L-band in the MeerKAT Large Area Synoptic Survey (MeerKLASS) campaign. The observations represent the deepest single-dish H i intensity maps to date, produced from 41 repeated scans over $236\, \deg ^2$, providing 62 h of observational data for each of the 64 dishes before flagging. By introducing an iterative self-calibration process, the estimated thermal noise of the reconstructed maps is limited to ${\sim }\, 1.21$ mK ($1.2\, \times$ the theoretical noise level). This thermal noise will be subdominant relative to the H i fluctuations on large scales ($k\, {\lesssim }\, 0.15\, h\, \text{Mpc}^{-1}$), which demands upgrades to power spectrum analysis techniques, particularly for covariance estimation. In this work, we present the improved MeerKLASS analysis pipeline, validating it on both a suite of mock simulations and a small sample of overlapping spectroscopic galaxies from the Galaxy And Mass Assembly (GAMA) survey. Despite only overlapping with ${\sim }\, 25~{{\ \rm per\ cent}}$ of the MeerKLASS deep field, and a conservative approach to covariance estimation, we still obtain a ${\gt }\, 4\, \sigma$ detection of the cross-power spectrum between the intensity maps and the 2269 galaxies at the narrow redshift range $0.39\, {\lt }\, z\, {\lt }\, 0.46$. We briefly discuss the H i autopower spectrum from these data, the detection of which will be the focus of follow-up work. For the first time with MeerKAT single-dish intensity maps, we also present evidence of H i emission from stacking the maps onto the positions of the GAMA galaxies.</jats:p>
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dc.identifierarxiv: arxiv:2407.21626
dc.identifier0035-8711
dc.identifierstaf195
dc.identifierhttps://www.repository.cam.ac.uk/handle/1810/386062
dc.identifier1365-2966
dc.identifier.urihttps://repo.dare.co.zw/handle/123456789/183545
dc.languageen
dc.languageeng
dc.publisherOxford University Press (OUP)
dc.publisherhttps://doi.org/10.1093/mnras/staf195
dc.subject5101 Astronomical Sciences
dc.subject51 Physical Sciences
dc.titleMeerKLASS L-band deep-field intensity maps: entering the H I dominated regime
dc.typeArticle

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