Molecular Gas Morphologies in Nearby Main Sequence Galaxies from PHANGS (Sophia Stuber, 21-11-2023)
Channel: Academy of Athens
Date: 01/12/2023

Sophia K. Stuber
Max-Planck-Institut für Astronomie, Heidelberg, Germany
 
Abstract:
 
The morphology of a galaxy results from secular and  environmental processes during its evolutionary history.  As such, it is an important tracer of galaxy evolution. In   the first visual classification of morphologies based solely on the molecular gas distribution for a large sample  of 79 nearby main-sequence galaxies, using 1" resolution CO(2-1) ALMA observations taken as part of the PHANGS survey.  In this work, we devised a morphology classification scheme for different types of bars, spiral arms (grand-design, floc culent, multi-arm and smooth), rings (central and non-central rings) similar to the well-established optical ones, and further introduce classes to describe the shape of bar lanes. Not only do we find a generally good agreement between our cold gas based morphologies  and the ones based on stellar light, but also find that both our bars as well as grand-design spiral arms are preferentially found at the higher mass end of our sample. We find that the shape of bar lanes might be indicative of a bars evolutionary state: more curved bar lanes show a shorter radial extend in molecular gas and have lower molecular to stellar mass ratios than those with straighter geometries.