2024/04/10 by Rachel Friesen, Friesen, Rachel K., Emma Jarvis +1 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2404.07259
openalex publication_date 2024/04/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Most stars form in clusters and groups rather than in isolation. We present \lesssim 5′′ angular resolution (∼ 2000 au, or 0.01 pc) Very Large Array NH3 (1,1), (2,2), and (3,3) and 1.3 cm continuum emission observations of the dense gas within the Serpens South protocluster and extended filaments to the north and south. We identify 94 dense cores using a dendrogram analysis of the NH3 (1,1) integrated intensity. Gas temperatures TK and non-thermal linewidths σNT both increase towards the centre of the young stellar cluster, in the dense gas generally and in the cores specifically. We find that most cores (54%) are super-virial, with gravitationally bound cores located primarily in the filaments. Cores in the protocluster have higher virial parameters by a factor ∼ 1.7, driven primarily by the increased core σNT values. These cores cannot collapse to form stars unless they accrete additional mass or their core internal motions are reduced. The southern filament shows a significant velocity gradient previously interpreted as mass flow toward the cluster. We find more complex kinematics in the northern filament. We find a strong correlation between σNT and TK, and argue that the enhanced temperatures and non-thermal motions are due to mechanical heating and interaction between the protocluster-driven outflows and the dense gas. Filament-led accretion may also contribute to the increased σNT values. Assuming a constant fraction of core mass ends up in the young stars, future star formation in the Serpens South protocluster will shift to higher masses by a factor ∼ 2.