CHANG-ES XXV: HI Imaging of Nearby Edge-on Galaxies -- Data Release 4

TL;DR

This paper presents HI imaging data for 19 nearby edge-on galaxies from the CHANG-ES survey, including new and improved maps, and analyzes the correlation between HI and radio continuum scale heights to understand galaxy disk physics.

Contribution

It provides the first HI interferometric images for two galaxies and enhances existing HI data for others, offering insights into the vertical distribution of HI and radio continuum in edge-on galaxies.

Findings

HI images for 19 galaxies are available, with 2 presented for the first time.

HI and radio continuum scale heights are well correlated in inclined galaxies.

Vertical distributions of HI and radio continuum are governed by similar physics with subtle differences.

Abstract

We present the HI distribution of galaxies from the Continuum Halos in Nearby Galaxies - an EVLA Survey (CHANG-ES). Though the observational mode was not optimized for detecting HI, we successfully produce HI cubes for 19 galaxies. The moment-0 maps from this work are available on CHANG-ES data release website, i.e., https://www.queensu.ca/changes. Our sample is dominated by star-forming, HI-rich galaxies at distances from 6.27 to 34.1 Mpc. HI interferometric images on two of these galaxies (NGC 5792 and UGC 10288) are presented here for the first time, while 12 of our remaining sample galaxies now have better HI spatial resolutions and/or sensitivities of intensity maps than those in existing publications. We characterize the average scale heights of the HI distributions for a subset of most inclined galaxies (inclination > 80 deg), and compare them to the radio continuum intensity scale heights, which have been derived in a similar way. The two types of scale heights are well correlated, with similar dependence on disk radial extension and star formation rate surface density but different dependence on mass surface density. This result indicates that the vertical distribution of the two components may be governed by similar fundamental physics but with subtle differences.