Model Independent Reconstruction of Galaxy Stellar Velocity Map

Abstract

We develop a model independent, robust method for determining galaxy rotation velocities across a 2D array of spaxels from an integral field spectrograph. Simulations demonstrate the method is accurate down to lower spectral signal-to-noise than standard methods: 99\% accurate when median $S/N=4$. We apply it to MaNGA data to construct the galaxy velocity map and galaxy rotation curve. We also develop a highly efficient cubic smoothing approach that is $25\times$ faster computationally and only slightly less accurate. Such model independent methods could be useful in studying dark matter properties without assuming a galaxy model.