Protostellar Outflows at the EarliesT Stages (POETS) VI. Evidence of disk-wind in G11.92-0.61 MM1

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Auteurs principaux: Bayandina, O. S., Moscadelli, L., Cesaroni, R., Beltrán, M. T., Sanna, A., Goddi, C.
Format: Preprint
Publié: 2025
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author Bayandina, O. S.
Moscadelli, L.
Cesaroni, R.
Beltrán, M. T.
Sanna, A.
Goddi, C.
author_facet Bayandina, O. S.
Moscadelli, L.
Cesaroni, R.
Beltrán, M. T.
Sanna, A.
Goddi, C.
contents Magnetohydrodynamic disk-winds play a key role in the formation of massive stars by providing the fine-tuning between accretion and ejection, where excess angular momentum is redirected away from the disk, allowing further mass growth. However, only a limited number of disk-wind sources have been detected to date. To better constrain the exact mechanism of this phenomenon, expanding the sample is critical. We performed an analysis of the disk-wind candidate G11.92-0.61 MM1 by estimating the physical parameters of the system and constraining the wind-launching mechanism. Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations were conducted in September 2021 with ALMA's longest baselines, which provided a synthesised beam of $\sim$30 mas. We obtained high-resolution images of the CH$_3$CN ($v_8=1$ and $v=0$), CH$_3$OH, SO$_2$, and SO molecular lines, and the 1.3 mm continuum. Our molecular data allowed us to refine the parameters of the disk-outflow system in MM1. The rotating disk is resolved into two regions with distinct kinematics: the inner region ($<$300 au) is traced by high-velocity emission of high-excitation CH$_3$CN lines and shows a Keplerian rotation; the outer region ($>$300 au), traced by mid-velocity CH$_3$CN emission, rotates in a sub-Keplerian regime. The central source is estimated to be $\sim$20 $M_{\odot}$, which is about half the mass estimated in previous lower-resolution studies. A strong collimated outflow is traced by SO and SO$_2$ emission up to $\sim$3400 au around MM1a. The SO and SO$_2$ emissions show a rotation-dominated velocity pattern, a constant specific angular momentum, and a Keplerian profile that suggests a magneto-centrifugal disk-wind origin with launching radii of $\sim$50-100 au. G11.92-0.61 MM1 appears to be one of the clearest cases of molecular line-traced disk-winds detected around massive protostars.
format Preprint
id arxiv_https___arxiv_org_abs_2501_17482
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Protostellar Outflows at the EarliesT Stages (POETS) VI. Evidence of disk-wind in G11.92-0.61 MM1
Bayandina, O. S.
Moscadelli, L.
Cesaroni, R.
Beltrán, M. T.
Sanna, A.
Goddi, C.
Solar and Stellar Astrophysics
Astrophysics of Galaxies
Magnetohydrodynamic disk-winds play a key role in the formation of massive stars by providing the fine-tuning between accretion and ejection, where excess angular momentum is redirected away from the disk, allowing further mass growth. However, only a limited number of disk-wind sources have been detected to date. To better constrain the exact mechanism of this phenomenon, expanding the sample is critical. We performed an analysis of the disk-wind candidate G11.92-0.61 MM1 by estimating the physical parameters of the system and constraining the wind-launching mechanism. Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations were conducted in September 2021 with ALMA's longest baselines, which provided a synthesised beam of $\sim$30 mas. We obtained high-resolution images of the CH$_3$CN ($v_8=1$ and $v=0$), CH$_3$OH, SO$_2$, and SO molecular lines, and the 1.3 mm continuum. Our molecular data allowed us to refine the parameters of the disk-outflow system in MM1. The rotating disk is resolved into two regions with distinct kinematics: the inner region ($<$300 au) is traced by high-velocity emission of high-excitation CH$_3$CN lines and shows a Keplerian rotation; the outer region ($>$300 au), traced by mid-velocity CH$_3$CN emission, rotates in a sub-Keplerian regime. The central source is estimated to be $\sim$20 $M_{\odot}$, which is about half the mass estimated in previous lower-resolution studies. A strong collimated outflow is traced by SO and SO$_2$ emission up to $\sim$3400 au around MM1a. The SO and SO$_2$ emissions show a rotation-dominated velocity pattern, a constant specific angular momentum, and a Keplerian profile that suggests a magneto-centrifugal disk-wind origin with launching radii of $\sim$50-100 au. G11.92-0.61 MM1 appears to be one of the clearest cases of molecular line-traced disk-winds detected around massive protostars.
title Protostellar Outflows at the EarliesT Stages (POETS) VI. Evidence of disk-wind in G11.92-0.61 MM1
topic Solar and Stellar Astrophysics
Astrophysics of Galaxies
url https://arxiv.org/abs/2501.17482