First Results from JACKS: A VLA Ammonia View of Gas Heating and Star-forming Cores in the Central Molecular Zone
Abstract
The Central Molecular Zone (CMZ) combines warm molecular gas, strong turbulence, and a star-formation rate below that expected from its dense-gas reservoir. The JVLA Ammonia C-configuration K-band Survey (JACKS) is designed to connect these environmental conditions to the thermal and kinematic structure of compact, potentially star-forming gas. JACKS follows the footprint of the ALMA Central Molecular Zone Exploration Survey (ACES) with 31 Very Large Array mosaic fields. Its K-band setup covers the metastable NH3 (1,1)--(5,5) inversion transitions, five non-metastable NH3 lines, the 22-GHz H2O maser transition, H64α and H66α, and broad continuum windows. The nominal resolutions are approximately 1.5'' ($0.06$ pc at the Galactic Centre) and $0.4$ km s−1 for the NH3 lines. We present preliminary imaging products that demonstrate water-maser self-calibration, compact and extended continuum emission, filamentary NH3 structure, and complex compact sources with multiple velocity components. Tests that combine JACKS with the SWAG and HOPS ammonia surveys recover progressively larger angular scales. These early products establish the survey's ability to connect core-scale gas heating and kinematics to the cloud-scale CMZ environment; quantitative temperature, opacity, and core-population measurements will follow from the uniformly reduced data set.
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BibTeX
@misc{zhang2026first,
title = {{First Results from JACKS: A VLA Ammonia View of Gas Heating and Star-forming Cores in the Central Molecular Zone}},
author = {Xu Zhang and Xing Lu and Elisabeth A. C. Mills and Qizhou Zhang and Daniel L. Walker and Natalie O. Butterfield and Namitha Issac and Annika Schmiedeke and Suinan Zhang and JACKS collaborations},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.07522},
eprint = {2611.07522},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.07522},
}
RIS
TY - UNPB
TI - First Results from JACKS: A VLA Ammonia View of Gas Heating and Star-forming Cores in the Central Molecular Zone
AU - Xu Zhang
AU - Xing Lu
AU - Elisabeth A. C. Mills
AU - Qizhou Zhang
AU - Daniel L. Walker
AU - Natalie O. Butterfield
AU - Namitha Issac
AU - Annika Schmiedeke
AU - Suinan Zhang
AU - JACKS collaborations
PY - 2026
DA - 2026/11/05
PB - arXiv
DO - 10.48550/arxiv.2611.07522
UR - https://arxiv.org/abs/2611.07522
AB - The Central Molecular Zone (CMZ) combines warm molecular gas, strong turbulence, and a star-formation rate below that expected from its dense-gas reservoir. The JVLA Ammonia C-configuration K-band Survey (JACKS) is designed to connect these environmental conditions to the thermal and kinematic structure of compact, potentially star-forming gas. JACKS follows the footprint of the ALMA Central Molecular Zone Exploration Survey (ACES) with 31 Very Large Array mosaic fields. Its K-band setup covers the metastable NH_3 (1,1)--(5,5) inversion transitions, five non-metastable NH_3 lines, the 22-GHz H_2O maser transition, H64α and H66α, and broad continuum windows. The nominal resolutions are approximately 1.5'' ($0.06$ pc at the Galactic Centre) and $0.4$ km s^−1 for the NH_3 lines. We present preliminary imaging products that demonstrate water-maser self-calibration, compact and extended continuum emission, filamentary NH_3 structure, and complex compact sources with multiple velocity components. Tests that combine JACKS with the SWAG and HOPS ammonia surveys recover progressively larger angular scales. These early products establish the survey's ability to connect core-scale gas heating and kinematics to the cloud-scale CMZ environment; quantitative temperature, opacity, and core-population measurements will follow from the uniformly reduced data set.
ER -