{"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/forward-modelling-the-luminosity-distance-and","title":"Forward-modelling the Luminosity, Distance, and Size distributions of the Milky Way Satellites","arxiv_id":"2112.04511","date":"2021-12-08","proceeding":null,"authors":["Viraj Manwadkar","Andrey Kravtsov"],"abstract":"We use \\texttt{GRUMPY}, a simple regulator-type model for dwarf galaxy formation and evolution, to forward model the dwarf galaxy satellite population of the Milky Way (MW) using the Caterpillar zoom-in simulation suite. We show that luminosity and distance distributions of the model satellites are consistent with the distributions measured in the DES, PS1 and SDSS surveys, even without including a model for the orphan galaxies. We also show that our model for dwarf galaxy sizes can simultaneously reproduce the observed {\\it distribution} of stellar half-mass radii, $r_{1/2}$, of the MW satellites and the overall $r_{1/2}-M_\\star$ relation exhibited by observed dwarf galaxies. The model predicts that some of the observed faint stellar systems with $r_{1/2}<10$ pc are ultra-faint dwarf galaxies. Scaling of the stellar mass $M_\\star$ and peak halo mass $M_{\\rm peak}$ for the model satellites is not described by a power law, but has a clear flattening of $M_\\star-M_{\\rm peak}$ scaling at $M_{\\rm peak}<10^8\\,M_\\odot$ imprinted by reionization. As a result, the fraction of low mass haloes ($M_{\\rm peak} < 10^8\\, M_\\odot$) hosting galaxies with $M_V<0$ is predicted to be 50% at $M_{\\rm peak} \\sim 3.6 \\times 10^7\\,M_\\odot$. We find that such high fraction at that halo mass helps to reproduce the number of dwarf galaxies discovered recently in the HSC-SSP survey. Using the model we forecast that there should be the total of $440^{+201}_{-147}$ (68\\% confidence interval) MW satellites with $M_V < 0$ and $r_{1/2} > 10$ pc within 300 kpc and make specific predictions for the HSC-SSP, DELVE-WIDE and LSST surveys.","url_abs":"https://arxiv.org/abs/2112.04511v2","url_pdf":"https://arxiv.org/pdf/2112.04511v2.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":"forward-modelling-the-luminosity-distance-and","repo_url":"https://github.com/kibokov/grumpy_mw_forward_model","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}