kth.sePublications KTH
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Deep learning approach for identification of H ii regions during reionization in 21-cm observations - III. Image recovery
Laboratoire d'Astrophysique, Ecole Polytechnique Federale de Lausanne (EPFL), Observatoire de Sauverny, Chemin Pegasi 51, CH-1290 Versoix, Switzerland, Chemin Pegasi 51; Institute for Particle Physics and Astrophysics, ETH Zurich, Wolfgang-Pauli-Str 27, CH-8093 Zurich, Switzerland.
KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm University, Nordita, Hannes Alfvens väg 12, SE-106 91 Stockholm, Sweden, Hannes Alfvens väg 12.ORCID iD: 0000-0002-2560-536x
Institute for Data Science, FHNW University of Applied Sciences & Arts Northwestern Switzerland, Bahnhofstrasse 6, CH-5210 Windisch, Switzerland, Bahnhofstrasse 6; Space, Planetary & Astronomical Sciences & Engineering (SPASE), Indian Institute of Technology, Uttar Pradesh, Kanpur 208016, India.
Laboratoire d'Astrophysique, Ecole Polytechnique Federale de Lausanne (EPFL), Observatoire de Sauverny, Chemin Pegasi 51, CH-1290 Versoix, Switzerland.
Show others and affiliations
2025 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 541, no 1, p. 234-250Article in journal (Refereed) Published
Abstract [en]

The low-frequency component of the upcoming Square Kilometre Array Observatory (SKA-Low) will be sensitive enough to construct 3D tomographic images of the 21-cm signal distribution during reionization. However, foreground contamination poses challenges for detecting this signal, and image recovery will heavily rely on effective mitigation methods. We introduce SERENEt, a deep-learning framework designed to recover the 21-cm signal from SKA-Low's foreground-contaminated observations, enabling the detection of ionized (H ii) and neutral (H i) regions during reionization. SERENEt can recover the signal distribution with an average accuracy of 75 per cent at the early stages () and up to 90 per cent at the late stages of reionization (). Conversely, H i region detection starts at 92 per cent accuracy, decreasing to 73 per cent as reionization progresses. Beyond improving image recovery, SERENEt provides cylindrical power spectra with an average accuracy exceeding 93 per cent throughout the reionization period. We tested SERENEt on a 10-deg field-of-view simulation, consistently achieving better and more stable results when prior maps were provided. Notably, including prior information about H ii region locations improved 21-cm signal recovery by approximately 10 per cent. This capability was demonstrated by supplying SERENEt with ionizing source distribution measurements, showing that high-redshift galaxy surveys of similar observation fields can optimize foreground mitigation and enhance 21-cm image construction.

Place, publisher, year, edition, pages
Oxford University Press (OUP) , 2025. Vol. 541, no 1, p. 234-250
Keywords [en]
dark ages, reionization, first stars, early Universe, techniques: image processing, techniques: interferometric
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:kth:diva-368815DOI: 10.1093/mnras/staf973ISI: 001519844500001Scopus ID: 2-s2.0-105009578334OAI: oai:DiVA.org:kth-368815DiVA, id: diva2:1994379
Note

QC 20250902

Available from: 2025-09-02 Created: 2025-09-02 Last updated: 2025-09-02Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records

Giri, Sambit K.

Search in DiVA

By author/editor
Giri, Sambit K.
By organisation
Nordic Institute for Theoretical Physics NORDITA
In the same journal
Monthly notices of the Royal Astronomical Society
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 14 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf