The dynamical environment of the high-mass star-forming region G28.288−0.364

@misc{dey2026dynamical,
  title = {{The dynamical environment of the high-mass star-forming region G28.288$-$0.364}},
  author = {Jyotirmoy Dey and Devendra K. Ojha and Jagadheep D. Pandian},
  howpublished = {arXiv},
  year = {2026},
  month = jul,
  doi = {10.48550/arxiv.2607.13942},
  eprint = {2607.13942},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2607.13942},
}

TY  - UNPB
TI  - The dynamical environment of the high-mass star-forming region G28.288−0.364
AU  - Jyotirmoy Dey
AU  - Devendra K. Ojha
AU  - Jagadheep D. Pandian
PY  - 2026
DA  - 2026/07/15
PB  - arXiv
DO  - 10.48550/arxiv.2607.13942
UR  - https://arxiv.org/abs/2607.13942
AB  - Massive stars form within deeply embedded dust cores, and the development of hypercompact and ultracompact H II regions characterizes their early evolution. Identifying and analyzing such regions is essential for understanding the physical processes that govern massive star formation and the transitions between early evolutionary stages. In this article, we investigate the physical and kinematic properties of the massive star-forming region G28.288−0.364 to constrain the evolutionary stages of embedded H II regions and the surrounding cores. We analyze multiwavelength observations, including uGMRT radio continuum data; archival continuum and radio recombination line data from the GLOSTAR-D survey; high-angular-resolution ALMA Band 3 radio recombination line and 1.36-mm dust continuum data from the ALMAGAL survey; and complementary molecular line tracers. We derive spectral indices, measure linewidths and velocities of the radio recombination line emission, identify compact dust cores using dendrogram analysis, and estimate their physical properties. The radio continuum emission exhibits a positive spectral index, consistent with partially optically thick free-free emission. High-resolution observations resolve the ionized gas into two distinct components with physical sizes of ∼ 0.06 pc, and their RRL linewidths (∼ 37 and 32 km s^−1, respectively) indicate that one component is in a transitional stage between hypercompact and ultracompact H II regions, while the other is more evolved. The 1.36-mm dust continuum data reveal five dust cores with surface densities consistent with the theoretical threshold for massive star formation. In summary, these results highlight the complex and sequential nature of massive star formation in clustered environments and demonstrate the importance of high angular resolution observations for resolving the early evolution of massive stars.
ER  -