MeerKAT HI line observations of the nearby interacting galaxy pair NGC 1512/1510

TL;DR

This paper presents high-resolution MeerKAT HI observations of the interacting galaxy pair NGC 1512/1510, revealing detailed gas structures, their relation to star formation, and demonstrating MeerKAT's imaging capabilities.

Contribution

First detailed measurements of HI arm lengths and masses in NGC 1512/1510 using MeerKAT, linking HI distribution to star formation and galaxy interaction features.

Findings

HI arms extend over ~27 kpc and contain >30% of total HI mass.

Starburst regions correlate with high HI surface densities (~12.5 Msun/pc^2).

HI content influences star formation conditions across the system.

Abstract

We present MeerKAT HI line observations of the nearby interacting galaxy pair NGC 1512/1510. The MeerKAT data yield high-fidelity image sets characterised by an excellent combination of high angular resolution (~20") and and sensitivity (~0.08 Msun/pc^2), thereby offering the most detailed view of this well-studied system's neutral atomic hydrogen content, especially the HI co-located with the optical components of the galaxies. The stellar bulge and bar of NGC 1512 are located within a central HI depression where surface densities fall below 1 Msun/pc^2, while the galaxy's starburst ring coincides with a well-defined HI annulus delimited by a surface density of 3 Msun/pc^2. In stark contrast, the star-bursting companion, NGC 1510, has its young stellar population precisely matched to the highest HI over-densities we measure (~12.5 Msun/pc^2). The improved quality of the MeerKAT data warrants the first detailed measurements of the lengths and masses of the system's tidally-induced HI arms. We measure the longest of the two prominent HI arms to extend over ~27 kpc and to contain more than 30% of the system's total HI mass. We quantitatively explore the spatial correlation between HI and far-ultraviolet flux over a large range of HI mass surface densities spanning the outer disk. The results indicate the system's HI content to play an important role in setting the pre-conditions required for wide-spread, high-mass star formation. This work serves as a demonstration of the remarkable efficiency and accuracy with which MeerKAT can image nearby systems in HI line emission.