{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"5b3da6593aca70f8e22d2e16140477cba61336765ccbc34fed81ea17ae7d553a","created":"2026-10-03T07:17:55Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"47638b3b67c7fe6e3bdd0be1e9fc15282e7a9dac408f7077b5041bba40747cbe","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"astro.star-formation-imf.bottom-heavy-ellipticals","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"Spectra and motions of stars in the centers of the biggest galaxies suggest they hold more small, dim stars than the Milky Way does. Some gravitational lensing measurements disagree.","posed_since":"2010","precise":"In cores of massive early-type galaxies (velocity dispersion $>2.5x10^7\\ \\mathrm{cm/s}$), gravity-sensitive absorption features (Na I 8190 Angstrom, Wing-Ford FeH band) and dynamical mass-to-light ratios imply an excess of stars with $m<0.3\\ M_{\\mathrm{sun}}$ relative to a Milky Way IMF. Determine whether the excess is real, its radial profile, and its dependence on velocity dispersion and metallicity, resolving the disagreement with lensing systems that favor a Milky Way IMF.","problem_ref":null,"references":"","settled_by":"Joint stellar-population, dynamical and lensing analysis of the same galaxies with consistent dark matter and stellar population models.","status_note":"","title":"Do massive elliptical galaxies contain excess low-mass stars?","topic_ref":"1d2b0b50573bf9dda12f66ffd1c6cc349d560012e5ad2243b57b088401422493"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"bbfcb59a8b78fac574665f4ba3cfb1286d6dd63dc9dcbd83dee23cf4dbcd07fe","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"1e2c6a3d3c5c877a7fc4394546d2d864daf35ecdc8dc7f3ed2ddeb07ca6793ad","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"VHDj6CbHEF4-j1CvQrrDxDEhQmmZScW7waCqIc9NhpLxA5_Nxd92zt-EithHPug9XZcBupXSBO_A-I3XkShGCA"},"schema":"pubphys.envelope/1"},"record_hash":"bbfcb59a8b78fac574665f4ba3cfb1286d6dd63dc9dcbd83dee23cf4dbcd07fe","leaf_index":625}