A Robust Method to Measure Centroids of Spectral Lines
Abstract
Measuring the centroid of a spectral line is a common problem in astronomy. Many methods have been devised to overcome limitations due to either noise in the spectra or asymmetric profiles, the most common of which are the intensity weighted averages (first moment) or fits of analytical (typically Gaussian) profiles. If the spectral line can be considered a single component, we demonstrate that a simple quadratic fit to the pixel of maximum intensity and its two neighboring pixels provides a robust measure of the line centroid. This approach allows for a sub-velocity resolution precision on the line centroid, without be biases by noise or asymmetric features in the line profile and outperforming traditional methods in most situations.
Keywords
Cite
@article{arxiv.1809.10295,
title = {A Robust Method to Measure Centroids of Spectral Lines},
author = {Richard Teague and Daniel Foreman-Mackey},
journal= {arXiv preprint arXiv:1809.10295},
year = {2018}
}
Comments
Accepted by RNAAS. An open-source implementation of this method can be found at https://github.com/richteague/bettermoments