ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions – XV. Steady accretion from global collapse to core feeding in massive hub-filament system SDC335. Issue 3 (17th February 2023)

• Record Type: Journal Article
• Authors: Xu, Feng-Wei; Wang, Ke; Liu, Tie; Goldsmith, Paul F; Zhang, Qizhou; Juvela, Mika; Liu, Hong-Li; Qin, Sheng-Li; Li, Guang-Xing; Tej, Anandmayee; Garay, Guido; Bronfman, Leonardo; Li, Shanghuo; Wu, Yue-Fang; Gómez, Gilberto C; Vázquez-Semadeni, Enrique; Tatematsu, Ken'ichi; Ren, Zhiyuan; Zhang, Yong; Toth, L Viktor; Liu, Xunchuan; Yue, Nannan; Zhang, Siju; Baug, Tapas; Issac, Namitha; Stutz, Amelia M; Liu, Meizhu; Fuller, Gary A; Tang, Mengyao; Zhang, Chao; Dewangan, Lokesh; Lee, Chang Won; Zhou, Jianwen; Xie, Jinjin; Jiao, Wenyu; Wang, Chao; Liu, Rong; Luo, Qiuyi; Soam, Archana; Eswaraiah, Chakali;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 520:Issue 3(2023)
• Page Start: 3259
• Page End: 3285
• Publication Date: 2023-02-17
• Subjects: stars: formation -- stars: protostars -- ISM: kinematics and dynamics -- ISM: individual object: SDC335; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stad012
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present ALMA Band-3/7 observations towards 'the Heart' of a massive hub-filament system (HFS) SDC335, to investigate its fragmentation and accretion. At a resolution of ∼0.03 pc, 3 mm continuum emission resolves two massive dense cores MM1 and MM2, with $383(^{\scriptscriptstyle +234}_{\scriptscriptstyle -120})$ M ⊙ (10–24 % mass of 'the Heart') and $74(^{\scriptscriptstyle +47}_{\scriptscriptstyle -24})$ M ⊙, respectively. With a resolution down to 0.01 pc, 0.87 mm continuum emission shows MM1 further fragments into six condensations and multi-transition lines of H2 CS provide temperature estimation. The relation between separation and mass of condensations at a scale of 0.01 pc favors turbulent Jeans fragmentation where the turbulence seems to be scale-free rather than scale-dependent. We use the H 13 CO + J = 1 − 0 emission line to resolve the complex gas motion inside 'the Heart' in position-position-velocity space. We identify four major gas streams connected to large-scale filaments, inheriting the anti-clockwise spiral pattern. Along these streams, gas feeds the central massive core MM1. Assuming an inclination angle of 45(± 15)° and a H 13 CO + abundance of 5(± 3) × 10 −11, the total mass infall rate is estimated to be 2.40(± 0.78) × 10 −3 M ⊙ yr −1, numerically consistent with the accretion rates derived from the clump-scale spherical infall model and the core-scale outflows. The consistency suggests a continuous, near steady-state, and efficient accretion from global collapse, therefore ensuring core feeding. Our comprehensive study of SDC335 showcases the detailed gas kinematics in a prototypical massive infalling clump, and calls for further systematic and statistical studies in a large sample.