{"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/galaxy-tagging-photometric-redshift","title":"Galaxy Tagging: photometric redshift refinement and group richness enhancement","arxiv_id":"1802.09009","date":"2018-02-25","proceeding":null,"authors":["P. R. Kafle","A. S. G. Robotham","S. P. Driver","S. Deeley","P. Norberg","M. J. Drinkwater","L. J. Davies"],"abstract":"We present a new scheme, $\\it{galtag}$, for refining the photometric redshift measurements of faint galaxies by probabilistically tagging them to observed galaxy groups constructed from a brighter, magnitude-limited spectroscopy survey. First, this method is tested on the DESI light-cone data constructed on the GALFORM galaxy formation model to tests its validity. We then apply it to the photometric observations of galaxies in the Kilo-Degree Imaging Survey (KiDS) over a 1 deg$^2$ region centred at 15$^\\mathrm{h}$. This region contains Galaxy and Mass Assembly (GAMA) deep spectroscopic observations (i-band<22) and an accompanying group catalogue to r-band<19.8. We demonstrate that even with some trade-off in sample size, an order of magnitude improvement on the accuracy of photometric redshifts is achievable when using $\\it{galtag}$. This approach provides both refined photometric redshift measurements and group richness enhancement. In combination these products will hugely improve the scientific potential of both photometric and spectroscopic datasets. The $\\it{galtag}$ software will be made publicly available at https://github.com/pkaf/galtag.git.","url_abs":"http://arxiv.org/abs/1802.09009v1","url_pdf":"http://arxiv.org/pdf/1802.09009v1.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":"galaxy-tagging-photometric-redshift","repo_url":"https://github.com/pkaf/galtag","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"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}