Predicting Continuum Emission in Massive Star-Forming Regions with Embedded HII Regions - Dust, Free-Free, and Anomalous Microwave Emission with POLARIS

@misc{reissl2026predicting,
  title = {{Predicting Continuum Emission in Massive Star-Forming Regions with Embedded HII Regions - Dust, Free-Free, and Anomalous Microwave Emission with POLARIS}},
  author = {Stefan Reissl and Alessio Traficante and Paolo Suin and Alice Nucara and Ralf S. Klessen and Leonardo Testi},
  howpublished = {arXiv},
  year = {2026},
  month = nov,
  doi = {10.48550/arxiv.2611.08891},
  eprint = {2611.08891},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2611.08891},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Predicting Continuum Emission in Massive Star-Forming Regions with Embedded HII Regions - Dust, Free-Free, and Anomalous Microwave Emission with POLARIS
AU  - Stefan Reissl
AU  - Alessio Traficante
AU  - Paolo Suin
AU  - Alice Nucara
AU  - Ralf S. Klessen
AU  - Leonardo Testi
PY  - 2026
DA  - 2026/11/06
PB  - arXiv
DO  - 10.48550/arxiv.2611.08891
UR  - https://arxiv.org/abs/2611.08891
AB  - Context: HII regions are a key stage of massive star formation, where ionizing radiation reshapes the interstellar medium. Their continuum spectra trace thermal dust, free-free emission, and anomalous microwave emission (AME). Aims: We investigate how these components evolve as an HII region expands and correlate with gas and electron column densities across spatial scales. Methods: We post-process RAMSES radiation-magnetohydrodynamical simulations of a 10^4 M_⊙ cloud with POLARIS. The model includes grain charging, rotational excitation and damping, radiative torques, rotational disruption, and emission from dust, ionized gas, and nano-composite grains. We compute maps and SEDs for six snapshots over 1−10^4 GHz and analyze multi-scale correlations. Results: Ionized emission evolves from a compact, optically thick HII region to an extended, optically thin structure. Around 15 GHz, free-free emission changes from a ν^2 to a ν^−0.1 spectral regime as optical depth decreases, and increasingly traces electron column density. The thermal dust peak shifts from mid- to far-infrared as colder material contributes, while dust emission remains strongly correlated with total gas column density. AME peaks at 26-37 GHz and shows scale-dependent correlations with gas and electron distributions. Rotational disruption is the main dust-destruction mechanism affecting mid-infrared emission and the high-frequency AME tail. Conclusions: These continuum components provide complementary, scale-dependent diagnostics of stellar feedback. Self-consistent multi-frequency modeling is essential for interpreting surveys of star-forming clouds.
ER  -