2024/04/16 by Massimo Pascale, Liang Dai, Pascale, Massimo +1 · 3 citations
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2404.10755
openalex publication_date 2024/04/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We suggest that "Godzilla" of the lensed Sunburst galaxy (z=2.37) is a young super star cluster powering a nebula of gravitationally trapped stellar ejecta. Employing HST photometry and spectroscopy from VLT/MUSE and VLT/X-Shooter, we infer physical and chemical properties of the cluster and nebula, finding Godzilla is young 4-6Myr, massive 2 × 106 M_\odot (1000/μ), a stellar metallicity Z ≃ 0.25 Z_\odot, and has a compact FUV component \lesssim 1\rm pc(1000/μ), where μ is the flux magnification factor. The gas is significantly enriched with N and He, indicating stellar wind material, and has highly elevated O relative to the stellar metallicity, indicating entrainment of CCSNe ejecta. The high density n\rm e ≃ 107-8\rm cm-3 implies a highly pressurized intracluster environment. We propose the pressure results from CCSN-driven supersonic turbulence in warm, self-shielding gas, which has accumulated in the cluster center after runaway radiative cooling and is dense enough to resist removal by CCSNe. The nebula gas shows sub-solar C/O, Ne/O and Si/O, which may reflect the CCSN element yields for initial stellar masses >40 M_\odot. A comparison to element yield synthesis models for young star clusters shows the gas abundances are consistent with complete retention and mixture of stellar winds and CCSNe ejecta until the inferred cluster age. The inferred O and He enhancement may have implications for the formation of multiple stellar populations in globular clusters, as stars formed from this gas would contradict the observed abundances of second-population stars.