Benchmarking Dimensionality Reduction Methods for High-Dimensional ALMA Image Cubes

TL;DR

This paper benchmarks various dimensionality reduction techniques on high-dimensional ALMA astronomical data cubes, evaluating their effectiveness, computational scalability, and suitability for astrophysical analysis and archival data processing.

Contribution

It provides a comprehensive comparison of linear and nonlinear reduction methods on real ALMA data, offering practical recommendations and insights into their performance and scalability.

Findings

Nonlinear methods better preserve astrophysical features.

Linear methods are computationally faster but less accurate.

Scalability varies significantly across methods.

Abstract

High-dimensional astronomical data cubes provide a wealth of spectral and structural information that can be used to study astrophysical and chemical processes. The complexity and sheer size of these datasets pose significant challenges in their efficient analysis, visualization, and interpretation. In specific astronomical use cases, a number of dimensionality reduction techniques, including traditional linear (e.g. principal component analysis) and modern nonlinear methods (e.g. convolutional autoencoders) have been used to tackle this high-dimensional problem. In this study, we assess the strengths, weaknesses, and nuances of various methods in their ability to capture and preserve astronomically-relevant features at lower dimensions. We provide recommendations to guide users in identifying and incorporating these treatments to their data, and provide insights into the computational scalability of these methods for observatory level data processing. This benchmark study uses publicly available archival ALMA data from a diverse sampling of source morphologies and observing setups to assess the performance and trade-offs between computational cost, image reconstruction accuracy, and scalability. Finally, we discuss the generalizability of these techniques in regard to data segmentation and labeling algorithms and how they can be exploited for advanced data product generation and streamlined archival analysis as we prepare to enter the era of the ALMA Wideband Sensitivity Upgrade.