Direct observational evidence of multi-epoch massive star formation in G24.47+0.49

• DOI: 10.48550/arxiv.2407.01063
• Publication Date: 2024-07-01
• Authors: Anindya Saha; Anandmayee Tej; Hongli Liu; Tie Liu; Guido Garay; P. F. Goldsmith; Chang Won Lee; Jinhua He; M. Juvela; L. Bronfman; Tapas Baug; Enrique Vázquez-S...; Patricio Sanhueza; Shanghuo Li; James O. Chibueze; N. K. Bhadari; L. K. Dewangan; Swagat R. Das; Fengwei Xu; Namitha Issac; Jihye Hwang; L. Viktor Tóth
• Keywords: Epoch (astronomy); Star (game theory)

Using new continuum and molecular line data from the ALMA Three-millimeter Observations of Massive Star-forming Regions (ATOMS) survey archival VLA, 4.86 GHz data, we present direct observational evidence hierarchical triggering relating three epochs massive star formation in a ring-like H II region, G24.47+0.49. We find radio flux analysis that it is excited by star(s) spectral type O8.5V-O8V first epoch formation. The swept-up ionized ring structure shows secondary collapse, within this burst observed different evolutionary phases, which constitutes second epoch. ATOMS (e.g., HCO$^+$(1-0)) observations reveal an outer concentric gas expanding at velocity $\sim$ 9 $\rm km\,s^{-1}$, constituting unambiguous detection ring. It harbors twelve dense cores with surface mass density greater than 0.05 g\,cm^{-2}$, threshold typical Half them are found to be subvirial, thus gravitational making third potential star-forming sites.