Distinguishing between the Strongest Millimeter Compact Emission and Maser and Outflow Activities in the G40.282–0.219 Massive Young Stellar Object Cluster
7 affiliations
- 1Xinjiang Astronomical Observatory
- 2University of Chinese Academy of Sciences
- 3Arba Minch University
- 4Xinjiang Key Laboratory of Radio Astrophysics
- 5Ural Federal University
- 6Institute of Astronomy and Astrophysics
- 7Nazarbayev University
Abstract
We present Atacama Large Millimeter/submillimeter Array (ALMA) 1.3 mm continuum and molecular-line observations of the star-forming region G40.282−0.219. The continuum resolves the source, previously considered a single massive young stellar object (MYSO), into three compact cores within a common natal clump. Using 13 bright molecular transitions, we investigate gas kinematics, chemistry, and evolutionary differences among the cores. MM1 is the dominant continuum source. MM2, the second-brightest core, drives a powerful outflow; its SiO jet shows velocity offsets of ±25 km s ⁻¹ from the systemic velocity. SiO jet and wider-angle H ₂ CO and CH ₃ OH emission trace the outflow, whose alignment with the H ₂ knot MHO 2463 suggests a preceding ejection from MM2. MM3 is weakest in continuum but appears to be the principal hot core, harboring Class II 6.7 GHz CH ₃ OH masers and the richest molecular inventory, including complex organic molecules (CH ₃ OH and CH ₃ CN) and shock/dense-gas tracers (OCS, HC ₃ N, H ₂ CO, and SO). We find clear spatial decoupling between continuum brightness and chemical, outflow, and maser activity. MM1 appears chemically poor, whereas weaker MM2 harbors outflow activity, and the least-bright MM3 contains an MYSO, the highest dust temperature, and the greatest chemical complexity. These hot cores may represent an evolutionary sequence from youngest MM1 to most evolved MM3 within one fragmenting clump. We conclude that accretion luminosity, localized heating, and evolutionary stage, rather than 1.3 mm continuum flux, likely govern observable chemical richness in clustered high-mass star-forming regions.
Related
- AT2025agpz in Rubin commissioning data: distinguishing a luminous interacting supernova from nuclear transients in compact galaxies
- Nuclear Millimeter Continuum Emission in Radio-Quiet Active Galactic Nuclei: an ALMA Spectral and Variability Study
- A Physically Motivated Compact Parameterization of Neutron Star Atmosphere Emission for Thermal X-ray Pulse-Profile Modeling
- Phase-Resolved Ultra-High-Energy Emission Defines an Energetic Boundary for Compact-Object Engines and Dense-Matter Structure
- Why is GN-z11 Bright, Compact, and Nitrogen Enhanced? Insights from UV Absorption and Emission Diagnostics
BibTeX
@article{tegegne2026distinguishing,
title = {{Distinguishing between the Strongest Millimeter Compact Emission and Maser and Outflow Activities in the G40.282–0.219 Massive Young Stellar Object Cluster}},
author = {A. G. Tegegne and Jarken Esimbek and Andrey M. Sobolev and Sergey Yu. Parfenov and Dmitry A. Ladeyschikov and Gang Wu and Sheng-Yuan Liu and Yu-Nung Su and Jianjun Zhou and Dalei Li and Xindi Tang and Yuxin He and Toktarkhan Komesh and Dongdong Zhou and Yingxiu Ma and Kadirya Tursun and Dilda Berdikhan and Jinjin Xie and Qaynar Jandaolet and Nurzhan Shaimoldin and Abay Jengis},
journal = {The Astrophysical Journal},
year = {2026},
month = oct,
doi = {10.3847/1538-4357/aea6ad},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/aea6ad},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Distinguishing between the Strongest Millimeter Compact Emission and Maser and Outflow Activities in the G40.282–0.219 Massive Young Stellar Object Cluster
AU - A. G. Tegegne
AU - Jarken Esimbek
AU - Andrey M. Sobolev
AU - Sergey Yu. Parfenov
AU - Dmitry A. Ladeyschikov
AU - Gang Wu
AU - Sheng-Yuan Liu
AU - Yu-Nung Su
AU - Jianjun Zhou
AU - Dalei Li
AU - Xindi Tang
AU - Yuxin He
AU - Toktarkhan Komesh
AU - Dongdong Zhou
AU - Yingxiu Ma
AU - Kadirya Tursun
AU - Dilda Berdikhan
AU - Jinjin Xie
AU - Qaynar Jandaolet
AU - Nurzhan Shaimoldin
AU - Abay Jengis
PY - 2026
DA - 2026/10/22
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/aea6ad
UR - https://iopscience.iop.org/article/10.3847/1538-4357/aea6ad
AB - We present Atacama Large Millimeter/submillimeter Array (ALMA) 1.3 mm continuum and molecular-line observations of the star-forming region G40.282−0.219. The continuum resolves the source, previously considered a single massive young stellar object (MYSO), into three compact cores within a common natal clump. Using 13 bright molecular transitions, we investigate gas kinematics, chemistry, and evolutionary differences among the cores. MM1 is the dominant continuum source. MM2, the second-brightest core, drives a powerful outflow; its SiO jet shows velocity offsets of ±25 km s ⁻¹ from the systemic velocity. SiO jet and wider-angle H ₂ CO and CH ₃ OH emission trace the outflow, whose alignment with the H ₂ knot MHO 2463 suggests a preceding ejection from MM2. MM3 is weakest in continuum but appears to be the principal hot core, harboring Class II 6.7 GHz CH ₃ OH masers and the richest molecular inventory, including complex organic molecules (CH ₃ OH and CH ₃ CN) and shock/dense-gas tracers (OCS, HC ₃ N, H ₂ CO, and SO). We find clear spatial decoupling between continuum brightness and chemical, outflow, and maser activity. MM1 appears chemically poor, whereas weaker MM2 harbors outflow activity, and the least-bright MM3 contains an MYSO, the highest dust temperature, and the greatest chemical complexity. These hot cores may represent an evolutionary sequence from youngest MM1 to most evolved MM3 within one fragmenting clump. We conclude that accretion luminosity, localized heating, and evolutionary stage, rather than 1.3 mm continuum flux, likely govern observable chemical richness in clustered high-mass star-forming regions.
SN - 0004-637X
SN - 1538-4357
ER -