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.

中文翻译：

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具有不同运动学的恒星种群合成：SDSS-IV MaNGA 星系中的多年龄非对称漂移

我们首次对 1.5 Gyr 以上和以下不同特征年龄的未解析恒星群进行了不对称漂移 (AD) 测量。这些测量对星系盘中的年龄-速度关系 (AVR) 进行采样。在第一篇论文中，我们开发了两种有效的算法来从光学积分场光谱 (IFS) 数据立方体中逐个像素地提取 AD。这些算法应用了不同的光谱模板，一种使用简单的恒星群，另一种使用恒星库；他们的比较使我们能够评估导出的多分量速度中的系统误差，例如模板不匹配。我们使用模拟谱和蒙特卡罗马尔可夫链对来自 SDSS-IV 中 MaNGA 调查的真实数据测试算法可靠性。我们将 AD 中的随机和系统误差量化为信噪比和恒星种群特性的函数，目的是将该技术应用于 MaNGA 星系样本的大子集。为了演示我们的方法，我们将它们应用于七个星系的初始样本，这些星系的恒星质量和颜色与银河系相当。我们为年轻和年老的恒星群体发现了范围广泛的不同 AD 径向剖面。