ALMA Observations of Massive Clouds in the Central Molecular Zone: External-pressure-confined Dense Cores and Salpeter-like Core Mass Functions

• DOI: 10.3847/1538-4357/ad9f28
• Publication Date: 2025-02-03T17:30:12Z
• Authors: Zhenying 朕荧 Zhang 张; Xing 行 Lu 吕; Tie 铁 Liu 刘; Sheng-Li 胜利 Qin 秦; Adam Ginsburg; Yu 宇 Cheng 程; Hauyu Baobab Liu; Daniel L. Walker; Xindi 新弟 Tang 汤; Shanghuo 尚活 Li 李; Qizhou Zhang; Thushara Pillai; Jens Kauffmann; Cara Battersby; Siyi 思轶 Feng 冯; Suinan 遂楠 Zhang 张; Qi-Lao 琦烙 Gu 顾; Fengwei 峰玮 Xu 许; Wenyu 文裕 Jiao 焦; Xunchuan 训川 Liu 刘; Li 立 Chen 陈; Qiu-yi 秋怡 Luo 罗; Xiaofeng 晓枫 Mai 麦; Zi-yang 紫杨 Li 李; Dongting 东庭 Yang 杨; Xianjin 先进 Shen 沈; Meizhu 梅竹 Liu 刘; Zhiqiang Shen
• Keywords: Submillimeter Array; Protostar

Abstract We present Atacama Large Millimeter/submillimeter Array Band 6 (1.3 mm) observations of dense cores in three massive molecular clouds within the central zone (CMZ) Milky Way, including Dust Ridge cloud e, Sgr C, and 20 km s −1 cloud, at a spatial resolution 2000 au. Among 834 identified from 1.3 mm continuum, we constrain temperatures linewidths 253 using local thermodynamic equilibrium methods to fit H 2 CO and/or CH 3 CN spectra. determine their masses dust continuum derived temperatures, then evaluate virial parameters construct core mass functions (CMFs). find that contribution external pressure is crucial for clouds, which contrasts with environment Galactic disk where are already bound, even without pressure. With our new temperature estimates also CMFs show Salpeter-like slope high-mass (≳3–6 M ⊙ ) end, change previous works. Combined possible top-heavy initial (IMFs) CMZ, result suggests gas accretion further fragmentation may play important roles transforming CMF IMF.