Abstract

Contributed Talk - Splinter Computational

Friday, 13 September 2024, 14:35   (S26)

Zoomed view of molecular cloud evolution under the impact by multiple supernovae

Masato Kobayashi, Daniel Seifried, Stefanie Walch-Gassner
University of Cologne

Recent observations suggest that bubble structures ubiquitously exist in the the interstellar medium (ISM) across the Universe, from the vicinity of our Solar system to nearby star-forming galaxies. The bubble expansions, driven by HII regions, supernovae, and superbubbles, significantly influence the dynamical and thermal states of pre-existing molecular clouds in their neighboring ISM. In particular, the impact by not only a single supernova but also by multiple supernovae is important to understand molecular cloud evolution, because recent theoretical studies suggest that the lifetime of molecular clouds is long enough to experience many shock compressions by multiple supernovae. Here, we start from our simulations of a stratified galactic disk ("Simulating the Life-Cycle of molecular Clouds”, a.k.a. SILCC project) and perform a zoomed simulations toward a molecular cloud. To understand the supernova's impact, we employ controlled setups where (1) the zoomed cloud has no nearby supernova, (2) it has a single supernova at 25 pc distance, and (3) it has 6 supernovae at 25 pc distance. Our results show that multiple supernovae significantly enhance/sustain the turbulence to the > 10 km/s level on a spatial scale of 1 - 100 pc but for a relatively short timescale of ~ 2 Myr. We also perform a synthetic observation in 12CO rotational transition lines by using RADMC3D to reveal the observational signature to understand those dynamics. Our results indicate that, even in the most ideal limit where we can observe all the faint emission, 12CO(1-0) emission traces only 25 percent of the total turbulent energy in this cloud, because of the lack of the CO abundance in the inside of supernova remnants and in turbulent diffuse volumes. In this presentation, we will also explore the capability to detect those turbulent enhancement in ALMA, IRAM 30m, and CCAT-prime etc. We will also present the more details of the statistics of high density clumps and their turbulent motion in molecular clouds to discuss the implication to the subsequent star formation.