Measurements of one-point statistics in 21-cm intensity maps via foreground avoidance strategy

Simple item page
dc.contributor.authorKittiwisit, Piyanat
dc.contributor.authorBowman, Judd D.
dc.contributor.authorMurray, Steven G.
dc.date.accessioned2023-01-30T12:02:47Z
dc.date.available2023-01-30T12:02:47Z
dc.date.issued2022
dc.description.abstractMeasurements of the one-point probability distribution function and higher-order moments (variance, skewness, and kurtosis) of the high-redshift 21-cm fluctuations are among the most directstatistical probes of the non-Gaussian nature ofstructure formation and evolution during re-ionization. However, contamination from astrophysical foregrounds and instrument systematics pose significant challenges in measuring these statistics in real observations. In this work, we use forward modelling to investigate the feasibility of measuring 21-cm one-point statistics through a foreground avoidance strategy. Leveraging the characteristic wedge-shape of the foregrounds in k-space, we apply a wedge-cut filtre that removes the foreground contaminated modes from a mock data set based on the Hydrogen Epoch of Re-ionization Array (HERA) instrument, and measure the one-point statistics from the image-space representation of the remaining non-contaminated modes. We experiment with varying degrees of wedge-cutting over different frequency bandwidths and find that the centre of the band is the least susceptible to bias from wedge-cutting. Based on this finding, we introduce a rolling filtre method that allows reconstruction of an optimal wedge-cut 21-cm intensity map over the full bandwidth using outputs from wedge-cutting over multiple sub-bands. We perform Monte Carlo simulations to show that HERA should be able to measure the rise in skewness and kurtosis near the end of re-ionization with the rolling wedge-cut method if foreground leakage from the Fourier transform window function can be controlled.en_US
dc.identifier.citationKittiwisit, P. et al. (2022). Measurements of one-point statistics in 21-cm intensity maps via foreground avoidance strategy. Monthly Notices of the Royal Astronomical Society, 517(2), 2138-2150. https://doi.org/10.1093/mnras/stac2826en_US
dc.identifier.issn1365-2966
dc.identifier.issnhttps://doi.org/10.1093/mnras/stac2826
dc.identifier.urihttp://hdl.handle.net/10566/8319
dc.language.isoenen_US
dc.publisherOxford University Pressen_US
dc.subjectStatisticsen_US
dc.subjectCosmologyen_US
dc.subjectRe-ionizationen_US
dc.subjectAstronomyen_US
dc.subjectPhysicsen_US
dc.titleMeasurements of one-point statistics in 21-cm intensity maps via foreground avoidance strategyen_US
dc.typeArticleen_US

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
kittiwisit_measurements of one-point statistics_2022.pdf
Size:
2.8 MB
Format:
Adobe Portable Document Format
Description:
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)