MIAO-ALMA: Shocks and Protostellar Outflows in 70 μm-dark clumps with L/M < 1 L_⊙/M_⊙

@misc{lin2026miaoalma,
  title = {{MIAO-ALMA: Shocks and Protostellar Outflows in 70 $μ$m-dark clumps with $L/M$ $<$ 1 $L_\odot$/$M_\odot$}},
  author = {Shuting Lin and Siyi Feng and Junzhi Wang and Shanghuo Li and Dan Miao and Zhi-Yu Zhang and Sheng-Yuan Liu and Nami Sakai and Fengwei Xu and Hauyu Baobab Liu and Henrik Beuther and Di Li and Qizhou Zhang and Tie Liu and Patricio Sanhueza and Olli Sipilä and Ken'ichi Tatematsu and Jaime E. Pineda and Xing Lu},
  howpublished = {arXiv},
  year = {2026},
  month = aug,
  doi = {10.48550/arxiv.2608.21978},
  eprint = {2608.21978},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2608.21978},
}

TY  - UNPB
TI  - MIAO-ALMA: Shocks and Protostellar Outflows in 70 μm-dark clumps with L/M < 1 L_⊙/M_⊙
AU  - Shuting Lin
AU  - Siyi Feng
AU  - Junzhi Wang
AU  - Shanghuo Li
AU  - Dan Miao
AU  - Zhi-Yu Zhang
AU  - Sheng-Yuan Liu
AU  - Nami Sakai
AU  - Fengwei Xu
AU  - Hauyu Baobab Liu
AU  - Henrik Beuther
AU  - Di Li
AU  - Qizhou Zhang
AU  - Tie Liu
AU  - Patricio Sanhueza
AU  - Olli Sipilä
AU  - Ken'ichi Tatematsu
AU  - Jaime E. Pineda
AU  - Xing Lu
PY  - 2026
DA  - 2026/08/22
PB  - arXiv
DO  - 10.48550/arxiv.2608.21978
UR  - https://arxiv.org/abs/2608.21978
AB  - To investigate the initial conditions of high-mass star-forming regions, we use SiO (2-1) emission to trace early shock-related kinematics toward sixteen 70 μm-dark and massive clumps with luminosity-to-mass ratios (L/M) < 1 L_⊙/M_⊙, as part of the Multiwavelength Line-Imaging Survey of the 70 μm-dark and bright clouds (MIAO) project. Using ALMA observations at a spatial resolution of ∼0.06 pc and a velocity resolution of 0.21 km s^−1, we identify a total of thirty-seven outflows with a variety of morphologies. Outflow parameters were derived by integrating the HCO^+ (1-0) line wings, excluding the quiescent dense core component traced by H^13CO^+ (1-0). We find that outflow masses and velocities show moderate positive correlations with the masses of their driving cores. Owing to the high sensitivity of our observations, which yield longer projected outflow lengths compared to previous studies, the derived outflow dynamical ages span ∼10^3-10^5 yr. We detect six narrow-linewidth (0.6-1.4 km s^−1) and three broad (> 2 km s^−1) SiO (2-1) features not associated with outflows driven by clearly identified protostars. Lacking coincident 3 mm dust continuum cores, their origins may be young outflows from undetected low-mass protostars, dissipating shocks, cloud-cloud collisions, or projection effects when the outflows lie close to the plane of the sky. The detection of these shocks and outflows in such extremely young environments demonstrates that protostellar activity has already begun.
ER  -