{"paper":{"title":"The contribution of HI-bearing ultra-diffuse galaxies to the cosmic number density of galaxies","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Aaron J. Romanowsky, Elizabeth A. K. Adams, Emmanouil Papastergis, Lukas Leisman, L. Y. Aaron Yung, Michael G. Jones, Rachel S. Somerville, Viraj Pandya","submitted_at":"2017-12-05T19:00:09Z","abstract_excerpt":"We estimate the cosmic number density of the recently identified class of HI-bearing ultra-diffuse sources (HUDs) based on the completeness limits of the ALFALFA survey. These objects fall in the range $8.5 < \\log M_{\\rm{HI}}/\\rm{M_{\\odot}} < 9.5$, have average $r$-band surface brightnesses fainter than 24 mag arsec$^{-2}$, half-light radii greater than 1.5 kpc, and are separated from neighbours by at least 350 kpc. We find that HUDs contribute at most 6% of the population of HI-bearing dwarfs, have a total cosmic number density of $(1.5 \\pm 0.6) \\times 10^{-3}$ $\\rm{Mpc^{-3}}$, and an HI mass"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1712.01855","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}