From Stellar Nurseries to Old Stellar Populations: A Multi-wavelength Case of NGC 1055

TL;DR

This study uses multi-wavelength data to analyze the complex interplay of gas, dust, and stellar populations in the spiral galaxy NGC 1055, revealing asymmetries and radial variations in physical properties across its disc.

Contribution

It provides a detailed multi-scale analysis of NGC 1055, highlighting asymmetries and radial trends in gas, dust, and stellar properties using combined CO, FUV, and NIR data.

Findings

Gas is more extended and brighter on the eastern side.

Physical properties decrease outward from the galaxy center.

Metallicity varies, with the color becoming bluer then redder outward.

Abstract

Given the complex nature of galaxies' interstellar medium (ISM), multi-wavelength data are required to probe the interplay among gas, dust, and stellar populations. Spiral galaxies are ideal laboratories for such a goal as they are rich in gas and dust. Using carbon monoxide (CO) along with GALEX far-ultraviolet (FUV) and Spitzer near-infrared (NIR) data we probe the correlations amongst the properties of stellar populations, gas, and dust over the disc of the spiral galaxy NGC~1055 at multiple angular resolutions, i.e. 2, 4, and 17 arcsec corresponding to a linear size of 144 pc, 288 pc, and 1.2 kpc, respectively. Our results indicate an asymmetry in the physical conditions along the galaxy's disc, i.e. the gas is slightly more extended and brighter, and molecular gas mass is higher on the disc's eastern side than the western side. All physical properties (i.e. molecular gas mass, CO line ratios, stellar mass, NIR emission) decrease from the centre going outwards in the disc with some exceptions (i.e. the extinction, FUV radiation, and the [3.6]-[4.5] colour). Our analysis indicates that the colour gets bluer (metallicity increases) halfway through the disc, then redder (metallicity decreases) going outwards further in the disc.