We present the first asymmetric drift (AD) measurements for unresolved stellar populations of different characteristic ages above and below 1.5 Gyr. These measurements sample the age-velocity relation (AVR) in galaxy disks. In this first paper we develop two efficient algorithms to extract AD on a spaxel-by-spaxel basis from optical integral-field spectroscopic (IFS) data-cubes. The algorithms apply different spectral templates, one using simple stellar populations and the other a stellar library; their comparison allows us to assess systematic errors in derived multi-component velocities, such as template-mismatch. We test algorithm reliability using mock spectra and Monte Carlo Markov Chains on real data from the MaNGA survey in SDSS-IV. We quantify random and systematic errors in AD as a function of signal-to-noise and stellar population properties with the aim of applying this technique to large subsets of the MaNGA galaxy sample. As a demonstration of our methods, we apply them to an initial sample of seven galaxies with comparable stellar mass and color to the Milky Way. We find a wide range of distinct AD radial profiles for young and old stellar populations.
@article{arxiv.2006.02071,
title = {Stellar Population Synthesis with Distinct Kinematics: Multi-Age Asymmetric Drift in SDSS-IV MaNGA Galaxies},
author = {Shravan Shetty and Matthew A. Bershady and Kyle B. Westfall and Michele Cappellari and Niv Drory and David R. Law and Renbin Yan and Kevin Bundy},
journal= {arXiv preprint arXiv:2006.02071},
year = {2020}
}
Comments
21 pages, 4 appendices, Accepted for publication in APJ