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Chemical and Physical Characterization of the Isolated Protostellar Source CB68: FAUST IV

2022; IOP Publishing; Volume: 934; Issue: 1 Linguagem: Inglês

10.3847/1538-4357/ac77e7

1538-4357

Muneaki Imai, Yoko Oya, Brian Svoboda, Hauyu Baobab Liu, B. Leflóch, S. Viti, Yichen Zhang, C. Ceccarelli, C. Codella, C. J. Chandler, Nami Sakai, Yuri Aikawa, F. O. Alves, Nadia Balucani, E. Bianchi, Mathilde Bouvier, G. Busquet, P. Caselli, E. Caux, Steven B. Charnley, Spandan Choudhury, Nicolás Cuello, M. De Simone, F. Dulieu, Aurora Durán, Lucy Evans, Cécile Favre, D. Fedele, Siyi Feng, F. Fontani, Logan Francis, Tetsuya Hama, Tomoyuki Hanawa, Eric Herbst, Shingo Hirano, Tomoya Hirota, Andrea Isella, I. Jiménez-Serra, Doug Johnstone, C. Kahane, Romane Le Gal, Laurent Loinard, A. López-Sepulcre, L. T. Maud, María José Maureira, F. Ménard, S. Mercimek, A. Miotello, G. Moellenbrock, Shoji Mori, Nadia M. Murillo, Riouhei Nakatani, Hideko Nomura, Yasuhiro Oba, Ross O’Donoghue, Satoshi Ohashi, Yuki Okoda, J. Ospina-Zamudio, J. E. Pineda, L. Podio, Albert Rimola, Takeshi Sakai, Dominique Segura-Cox, Yancy L. Shirley, V. Taquet, L. Testi, C. Vastel, Naoki Watanabe, Yoshimasa Watanabe, A. Witzel, Ci Xue, Bo Zhao, Satoshi Yamamoto,

Atmospheric Ozone and Climate

Abstract The chemical diversity of low-mass protostellar sources has so far been recognized, and environmental effects are invoked as its origin. In this context, observations of isolated protostellar sources without the influence of nearby objects are of particular importance. Here, we report the chemical and physical structures of the low-mass Class 0 protostellar source IRAS 16544−1604 in the Bok globule CB 68, based on 1.3 mm Atacama Large Millimeter/submillimeter Array observations at a spatial resolution of ∼70 au that were conducted as part of the large program FAUST. Three interstellar saturated complex organic molecules (iCOMs), CH 3 OH, HCOOCH 3 , and CH 3 OCH 3 , are detected toward the protostar. The rotation temperature and the emitting region size for CH 3 OH are derived to be 131 ± 11 K and ∼10 au, respectively. The detection of iCOMs in close proximity to the protostar indicates that CB 68 harbors a hot corino. The kinematic structure of the C 18 O, CH 3 OH, and OCS lines is explained by an infalling–rotating envelope model, and the protostellar mass and the radius of the centrifugal barrier are estimated to be 0.08–0.30 M ⊙ and <30 au, respectively. The small radius of the centrifugal barrier seems to be related to the small emitting region of iCOMs. In addition, we detect emission lines of c-C 3 H 2 and CCH associated with the protostar, revealing a warm carbon-chain chemistry on a 1000 au scale. We therefore find that the chemical structure of CB 68 is described by a hybrid chemistry. The molecular abundances are discussed in comparison with those in other hot corino sources and reported chemical models.