ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): A Forming Quadruple System with Continuum "Ribbons" and Intricate Outflows
Sanhueza, Patricio; Kwon, Woojin; Chen, Huei-Ru Vivien; Johnstone, Doug; Lee, Chang Won; Lee, Chin-Fei; Liu, Tie; Liu, Sheng-Yuan; Lu, Xing; Eden, David; Shang, Hsien; Ward-Thompson, D.; Li, Shanghuo; Qin, Sheng-Li; Tatematsu, Ken'ichi; Ren, Zhiyuan; Offner, Stella S. R.; Juvela, Mika; Goldsmith, Paul F.; Luo, Qiu-yi; Lee, Aaron T.; di Francesco, James; Mai, Xiaofeng; Liu, Xun-chuan; Xu, Feng-Wei; Dutta, Somnath; Yang, Aiyuan; Hirano, Naomi; Sahu, Dipen; Hsu, Shih-Ying; Bronfman, Leonardo; Rawlings, M. G.; Gu, Qi-lao; Shen, Zhi-Qiang
China, United States, Canada, Finland, Japan, Taiwan, Germany, South Korea, India, Chile, United Kingdom
Abstract
One of the most poorly understood aspects of low-mass star formation is how multiple-star systems are formed. Here we present the results of Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 observations toward a forming quadruple protostellar system, G206.93-16.61E2, in the Orion B molecular cloud. ALMA 1.3 mm continuum emission reveals four compact objects, of which two are Class I young stellar objects and the other two are likely in prestellar phase. The 1.3 mm continuum emission also shows three asymmetric ribbon-like structures that are connected to the four objects, with lengths ranging from ~500 to ~2200 au. By comparing our data with magnetohydrodynamic simulations, we suggest that these ribbons trace accretion flows and also function as gas bridges connecting the member protostars. Additionally, ALMA CO J = 2-1 line emission reveals a complicated molecular outflow associated with G206.93-16.61E2, with arc-like structures suggestive of an outflow cavity viewed pole-on.