Insights into the nature of dust attenuation in relation to galaxy evolution from local to cosmic noon galaxies

Abstract

The dust attenuation in galaxies depends on numerous processes and physical properties, such as the stellar mass, the star formation rate (SFR), the metallicity, the star formation history (SFH), and the star-dust geometry, which also involves morphology and inclination. Throughout the work in this thesis, we have studied each of these aspects to better understand how they affect the dust attenuation and its dust attenuation law through observational data from several different major telescopes. In this thesis, we present those results. First, we discuss work studying the dust attenuation, measured through the Balmer decrement, for a large sample of local star-forming galaxies from the Sloan Digital Sky Survey (SDSS). We use machine learning and advanced statistical techniques to study which galaxy physical parameter is the most important in determining the dust attenuation. We find that the stellar mass leads over all other parameters, with the metallicity and velocity dispersion also being important but less so than the stellar mass. We then compare these results with observations of galaxies at cosmic noon ($z\sim1-3$) from the Keck telescope and the Very Large Telescope, finding that there is no significant evolution in the relationship between the dust attenuation and the stellar mass. This indicates that the dust production mechanism connected to the stellar mass in star-forming galaxies is not evolving significantly between these epochs. Then, we present work using JWST/NIRCam photometry and JWST/NIRSpec spectroscopy of a sample of massive quiescent and star-forming galaxies observed at cosmic noon with the Blue Jay collaboration. We study the shape of the attenuation law and show that there is a large diversity correlated with the dust content, stellar mass, and SFR. We also observe the relationship between dust attenuation and stellar mass for star-forming galaxies and quiescent galaxies at cosmic noon. Incorporating morphological measurements from the NIRCam imaging, we identify a size gradient between the rest-optical and rest-NIR driven by the dust attenuation for the most massive galaxies. Lastly, we use the emission line measurements for a sub-sample of galaxies from the Blue Jay survey to measure directly the nebular attenuation law from the Balmer and Paschen emission lines. We find that the slopes of these attenuation laws vary significantly, indicating that there exists no universal nebular attenuation law that can be used to dust correct emission lines. Using the attenuation law of the stellar continuum derived through SED fitting, we find that the reddening of the nebular attenuation law and the reddening of the stellar continuum are overall consistent with each other since we are probing such highly star-forming galaxies. However, we also observe a tentative trend in which the nebular to stellar reddening ratio increases with stellar mass. We conclude this thesis by discussing possible future studies that can deepen our understanding of the nature of dust in galaxies across cosmic time.