Global and Local Infall in the ASHES Sample (GLASHES). III. Physical Parameters of Contracting Motion onto Dense Cores in 70 μm Dark Massive Clumps
Abstract
Core growth is a key process in high-mass star formation. As part of the GLASHES (Global and Local Infall in the ASHES Sample) survey, we present infall velocities and mass infall rates derived from blue-asymmetric line profiles toward cores embedded in massive 70 \textmu m-dark clumps. Robust Hill5 model fits were obtained for 70 of the 135 cores exhibiting blue-asymmetric profiles, yielding infall velocities of 0.11--1.60 km s−1 and mass infall rates ranging from ∼10−5 to 5×10−3 M⊙ yr−1. Both quantities increase systematically from prestellar candidates to warm cores and outflow-associated cores. The inferred infall velocities are close to the cores' free-fall velocities (mean vin/vff∼0.75) and tin=R/vin is comparable to the free-fall time, indicating dynamical fast contraction. Hill5 infall velocity correlates moderately with the non-thermal velocity dispersion and Mach number measured from optically thin tracers, indicating that organized infall contributes to the observed line widths. The mass infall rate follows a power-law relation with core mass, Ṁ=1.3×10−4 (M/M⊙)0.83± 0.06 M⊙ yr−1, across 0.1 M⊙ ≲ M ≲ 30 M⊙. The power-law index increases from ∼0.65 for prestellar cores to ∼1.10 for outflow-associated cores, likely tracing an evolution in the dominant physical process. The Hill5 infall velocities and mass infall rates for the GLASHES cores are larger than those of cores in nearby low-mass star forming regions but smaller than those of larger scale high-mass clumps. These results provide the first statistical constraints on core-scale mass accumulation during the earliest stages of high-mass star formation.
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BibTeX
@misc{morii2026global,
title = {{Global and Local Infall in the ASHES Sample (GLASHES). III. Physical Parameters of Contracting Motion onto Dense Cores in 70 $μ$m Dark Massive Clumps}},
author = {Kaho Morii and Patricio Sanhueza and Qizhou Zhang and Philip C. Myers and James M. Jackson and Fumiaki Yoshida},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.10676},
eprint = {2610.10676},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.10676},
}
RIS
TY - UNPB
TI - Global and Local Infall in the ASHES Sample (GLASHES). III. Physical Parameters of Contracting Motion onto Dense Cores in 70 μm Dark Massive Clumps
AU - Kaho Morii
AU - Patricio Sanhueza
AU - Qizhou Zhang
AU - Philip C. Myers
AU - James M. Jackson
AU - Fumiaki Yoshida
PY - 2026
DA - 2026/10/07
PB - arXiv
DO - 10.48550/arxiv.2610.10676
UR - https://arxiv.org/abs/2610.10676
AB - Core growth is a key process in high-mass star formation. As part of the GLASHES (Global and Local Infall in the ASHES Sample) survey, we present infall velocities and mass infall rates derived from blue-asymmetric line profiles toward cores embedded in massive 70 \textmu m-dark clumps. Robust Hill5 model fits were obtained for 70 of the 135 cores exhibiting blue-asymmetric profiles, yielding infall velocities of 0.11--1.60 km s^−1 and mass infall rates ranging from ∼10^−5 to 5×10^−3 M_⊙ yr^−1. Both quantities increase systematically from prestellar candidates to warm cores and outflow-associated cores. The inferred infall velocities are close to the cores' free-fall velocities (mean v_in/v_ff∼0.75) and t_in=R/v_in is comparable to the free-fall time, indicating dynamical fast contraction. Hill5 infall velocity correlates moderately with the non-thermal velocity dispersion and Mach number measured from optically thin tracers, indicating that organized infall contributes to the observed line widths. The mass infall rate follows a power-law relation with core mass, Ṁ=1.3×10^−4 (M/M_⊙)^0.83± 0.06 M_⊙ yr^−1, across 0.1 M_⊙ ≲ M ≲ 30 M_⊙. The power-law index increases from ∼0.65 for prestellar cores to ∼1.10 for outflow-associated cores, likely tracing an evolution in the dominant physical process. The Hill5 infall velocities and mass infall rates for the GLASHES cores are larger than those of cores in nearby low-mass star forming regions but smaller than those of larger scale high-mass clumps. These results provide the first statistical constraints on core-scale mass accumulation during the earliest stages of high-mass star formation.
ER -