Connection between dynamically derived IMF normalisation and stellar populations
arXiv:1501.03927 · doi:10.1017/S1743921315003373
Abstract
In this contributed talk I present recent results on the connection between stellar population properties and the normalisation of the stellar initial mass function (IMF) measured using stellar dynamics, based on a large sample of 260 early-type galaxies observed as part of the Atlas3D project. This measure of the IMF normalisation is found to vary non-uniformly with age- and metallicity-sensitive absorption line strengths. Applying single stellar population models, there are weak but measurable trends of the IMF with age and abundance ratio. Accounting for the dependence of stellar population parameters on velocity dispersion effectively removes these trends, but subsequently introduces a trend with metallicity, such that `heavy' IMFs favour lower metallicities. The correlations are weaker than those found from previous studies directly detecting low-mass stars, suggesting some degree of tension between the different approaches of measuring the IMF. Resolving these discrepancies will be the focus of future work.
4 pages, 2 figures. To appear in Proceedings of IAU Symposium 311, Galaxy Masses as Constraints of Formation Models, M,. Cappellari & S. Courteau, eds
References in corpus (4)
- A systematic variation of the stellar initial mass function in early-type galaxies
- The Atlas3D Project - XXX. Star formation histories and stellar population scaling relations of early-type galaxies
- Population Synthesis in the Blue IV: Accurate Model Predictions for Lick Indices and UBV Colors in Single Stellar Populations
- Connection between dynamically derived IMF normalisation and stellar population parameters