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

Simple item page
dc.contributor.authorBull, Philip
dc.contributor.authorCamera, Stefano
dc.contributor.authorEngelbrecht, Brandon
dc.contributor.authorFonseca, José
dc.contributor.authorIrfan, Melis
dc.contributor.authorLi, Yichao
dc.contributor.authorPourtsidou, Alkistis
dc.contributor.authorSantos, Mario
dc.contributor.authorSpinelli, Marta
dc.contributor.authorWang, Jingying
dc.contributor.authorWitzemann, Amadeus
dc.date.accessioned2025-10-27T09:10:54Z
dc.date.available2025-10-27T09:10:54Z
dc.date.issued2025
dc.description.abstractWe present results from MeerKAT single-dish HI 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 HI intensity maps to date, produced from 41 repeated scans over 236 deg2, 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 ∼ 1.21 mK (1.2 × the theoretical noise level). This thermal noise will be subdominant relative to the HI fluctuations on large scales (k ≲ 0.15 h 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 ∼ 25 per cent of the MeerKLASS deep field, and a conservative approach to covariance estimation, we still obtain a > 4 σ detection of the cross-power spectrum between the intensity maps and the 2269 galaxies at the narrow redshift range 0.39 < z < 0.46. We briefly discuss the HI 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 HI emission from stacking the maps onto the positions of the GAMA galaxies.
dc.identifier.citationM. Barberi-Squarotti, J. L. Bernal, P. Bull, S. Camera, I. P. Carucci, Z. Chen, et al. 2025. MeerKLASS L-band deep-field intensity maps: entering the H I dominated regime. Monthly Notices of the Royal Astronomical Society, 537, 3632-3661.
dc.identifier.urihttps://doi.org/10.1093/mnras/staf195
dc.identifier.urihttps://hdl.handle.net/10566/21142
dc.language.isoen
dc.publisherOxford University Press
dc.subjectCosmology: observations
dc.subjectLarge scale structure of Universe
dc.subjectMethods: data analysis
dc.subjectMethods: statistical
dc.subjectRadio lines: general
dc.titleMeerKLASS L-band deep-field intensity maps: entering the H I dominated regime
dc.typeArticle

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
bull_meerKLASS _L -band_ deep-field _intensity _maps_2025.pdf
Size:
5.39 MB
Format:
Adobe Portable Document Format
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

Research Articles (Physics)