Treffer: Near-field imaging of local interference in radio interferometric data: Impact on the redshifted 21 cm power spectrum

Title:
Near-field imaging of local interference in radio interferometric data: Impact on the redshifted 21 cm power spectrum
Authors:
Munshi, S, Mertens, F.G, Koopmans, L.V.E, Mevius, M, Offringa, A.R, Semelin, B, Viou, C, Bracco, A, Brackenhoff, S.A, Ceccotti, E, Chege, J.K, Fialkov, A, Gao, L.Y, Ghara, R, Ghosh, S, Shaw, A.K, Zarka, P, Zaroubi, S, Cecconi, B, Corbel, S, Girard, J.N, Griessmeier, Jean-Mathias, Konovalenko, O, Loh, A, Tokarsky, P, Ulyanov, O, Zakharenko, V
Contributors:
Laboratoire d’étude de l’Univers et des phénomènes eXtrèmes (LUX), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Astrophysique, Laboratoire de physique de l'ENS - ENS Paris (LPENS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Département de Physique de l'ENS-PSL, École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Département de Physique de l'ENS-PSL, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL), Laboratoire d’Instrumentation et de Recherche en Astrophysique (LIRA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Observatoire de Paris - Site de Meudon (OBSPM), Observatoire de Paris, Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES)
Source:
Astronomy & Astrophysics - A&A. 697:A203-A203
Publisher Information:
CCSD; EDP Sciences, 2025.
Publication Year:
2025
Collection:
collection:OBSPM
collection:CEA
collection:INSU
collection:ENS-PARIS
collection:CNRS
collection:UNIV-ORLEANS
collection:UNIV-CERGY
collection:CNES
collection:USN
collection:LORIA2
collection:OSUC
collection:LPC2E
collection:CEA-UPSAY
collection:PSL
collection:UNIV-PARIS-SACLAY
collection:SORBONNE-UNIVERSITE
collection:SORBONNE-UNIV
collection:LPENS
collection:UNIV-PARIS
collection:UNIVERSITE-PARIS
collection:UP-SCIENCES
collection:ENS-PSL
collection:OBSPM-PSL
collection:UNIVERSITE-PARIS-SACLAY
collection:SU-TI
collection:ALLIANCE-SU
collection:SUPRA_ASTRO_PHYS
collection:LIR
collection:LUX
collection:LIRA-OBS
collection:ORN
Subject Terms:
[PHYS.PHYS.PHYS-INS-DET]Physics [physics], Physics [physics], Instrumentation and Detectors [physics.ins-det], [PHYS.ASTR]Physics [physics], Astrophysics [astro-ph]
Original Identifier:
ARXIV: 2503.21728
INSPIRE: 2905156
HAL: hal-05038118
Document Type:
Zeitschrift article<br />Journal articles
Language:
English
ISSN:
0004-6361
1432-0746
Relation:
info:eu-repo/semantics/altIdentifier/arxiv/2503.21728; info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/202554763
DOI:
10.1051/0004-6361/202554763
Access URL:
https://hal.science/hal-05038118
https://hal.science/hal-05038118v1/document
https://hal.science/hal-05038118v1/file/aa54763-25.pdf
Rights:
info:eu-repo/semantics/OpenAccess
URL: http://creativecommons.org/licenses/by/
Accession Number:
edshal.hal.05038118v1
Database:
HAL

Weitere Informationen

Radio-frequency interference (RFI) is a major systematic limitation in radio astronomy, particularly for science cases requiring high sensitivity, such as 21 cm cosmology. Traditionally, RFI is dealt with by identifying its signature in the dynamic spectra of visibility data and flagging strongly affected regions. However, for RFI sources that do not occupy narrow regions in the time-frequency space, such as persistent local RFI, modeling these sources could be essential to mitigating their impact. This paper introduces two methods for detecting and characterizing local RFI sources from radio interferometric visibilities: matched filtering and maximum a posteriori (MAP) imaging. These algorithms use the spherical wave equation to construct three-dimensional near-field image cubes of RFI intensity from the visibilities. The matched filter algorithm can generate normalized maps by cross-correlating the expected contributions from RFI sources with the observed visibilities, while the MAP method performs a regularized inversion of the visibility equation in the near field. We developed a full polarization simulation framework for RFI and demonstrated the methods on simulated observations of local RFI sources. The stability, speed, and errors introduced by these algorithms were investigated, and, as a demonstration, the algorithms were applied to a subset of NenuFAR observations to perform spatial, spectral, and temporal characterization of two local RFI sources. We used simulations to assess the impact of local RFI on images, the uv plane, and cylindrical power spectra, and to quantify the level of bias introduced by the algorithms in order to understand their implications for the estimated 21 cm power spectrum with radio interferometers. The near-field imaging and simulation codes are publicly available in the Python library nfis.