Revision 1

Accepted · first revision · record

Title: Do massive elliptical galaxies contain excess low-mass stars?
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.
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.
Settled by: Joint stellar-population, dynamical and lensing analysis of the same galaxies with consistent dark matter and stellar population models.
Kind: well-posed
Answer type: yes-no
References: (empty)
Literature status: contested
Status note: (empty)
Posed since: 2010