{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/component-separated-cib-cleaned-thermal","title":"Component-separated, CIB-cleaned thermal Sunyaev--Zel'dovich maps from $\\textit{Planck}$ PR4 data with a flexible public needlet ILC pipeline","arxiv_id":"2307.01043","date":"2023-07-03","proceeding":null,"authors":["Fiona McCarthy","J. Colin Hill"],"abstract":"We use the full-mission $\\textit{Planck}$ PR4 data to construct maps of the thermal Sunyaev$--$Zel'dovich effect (Compton-$y$ parameter) in our Universe. To do so, we implement a custom needlet internal linear combination (NILC) pipeline in a Python package, $\\texttt{pyilc}$, which we make publicly available. We publicly release our Compton-$y$ maps, which we construct using various constrained ILC (\"deprojection\") options in order to minimize contamination from the cosmic infrared background (CIB) in the reconstructed signal. In particular, we use a moment-based deprojection which minimizes sensitivity to the assumed frequency dependence of the CIB. Our code $\\texttt{pyilc}$ performs needlet or harmonic ILC on mm-wave sky maps in a flexible manner, with options to deproject various components on all or some scales. We validate our maps and compare them to the official $\\textit{Planck}$ 2015 $y$-map, finding that we obtain consistent results on large scales and 10-20$\\%$ lower noise on small scales. We expect that these maps will be useful for many auto- and cross-correlation analyses; in a companion paper, we use them to measure the tSZ -- CMB lensing cross-correlation. We anticipate that $\\texttt{pyilc}$ will be useful both for data analysis and for pipeline validation on simulations to understand the propagation of foreground components through a full NILC pipeline.","url_abs":"https://arxiv.org/abs/2307.01043v3","url_pdf":"https://arxiv.org/pdf/2307.01043v3.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"component-separated-cib-cleaned-thermal","repo_url":"https://github.com/jcolinhill/pyilc","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}