Model Independent Reconstruction of Galaxy Stellar Velocity Map

TL;DR

This paper introduces a model-independent method for reconstructing galaxy velocity maps from integral field spectrograph data, achieving high accuracy at low signal-to-noise ratios and enabling dark matter studies without galaxy models.

Contribution

The authors present a new robust, model-independent technique for galaxy velocity reconstruction that outperforms standard methods in accuracy and efficiency, especially at low S/N.

Findings

Achieves 99% accuracy at median S/N=4

Cubic smoothing method is 25 times faster

Enables dark matter analysis without galaxy models

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.