FAUST

XXIII. SiO outflow in the protobinary system L483

¹ National Astronomical Observatory of Japan, 2-12 Hoshigaoka, Mizusawa, Oshu, Iwate 023-0861, Japan
² SOKENDAI (The Graduate University for Advanced Studies), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
³ Université de Bordeaux – CNRS Laboratoire d’Astrophysique de Bordeaux, 33600 Pessac, France
⁴ Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto-shi, Kyoto-fu 606-8502, Japan
⁵ Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
⁶ Astrochemistry Laboratory, Code 691, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, USA
⁷ Centro de Astrobiología (CAB), INTA-CSIC, Ctra. de Torrejón a Ajalvir, km 4, 28850, Torrejón de Ardoz, Spain
⁸ Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
⁹ Institut de Radioastronomie Millimétrique, 38406 Saint-Martin d'Hères, France
¹⁰ European Southern Observatory, Karl-Schwarzschild Str. 2, 85748 Garching bei München, Germany
¹¹ IRAP, Univ. de Toulouse, CNRS, CNES, UPS, Toulouse, France
¹² National Radio Astronomy Observatory, PO Box O, Socorro, NM 87801, USA
¹³ Instituto Nazionale di Astrofisica (INAF), Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
¹⁴ RIKEN Cluster for Pioneering Research, 2-1, Hirosawa, Wako-shi, Saitama 351-0198, Japan
¹⁵ Department of Astronomy, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
¹⁶ Department of Chemistry, Biology, and Biotechnology, The University of Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
¹⁷ Center for Astrochemical Studies, Max-Planck-Institut für extraterrestrische Physik (MPE), Gie βenbachstr. 1, 85741 Garching, Germany
¹⁸ CY Cergy Paris Université, Sorbonne Université, Observatoire de Paris, PSL University, CNRS, LERMA, 95000, Cergy, France
¹⁹ School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
²⁰ Department of Astronomy, Xiamen University, Xiamen, Fujian 361005, PR China
²¹ Max-Planck-Institut für extraterrestrische Physik (MPE), Gie βenbachstr. 1, D-85741 Garching, Germany
²² Laboratoire d'Études du Rayonnement et de la Matière en Astrophysique et Atmosphères (LERMA), Observatoire de Paris, Meudon, France
²³ Komaba Institute for Science, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
²⁴ Department of Basic Science, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
²⁵ Center for Frontier Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
²⁶ Department of Chemistry, University of Virginia, McCormick Road, PO Box 400319, Charlottesville, VA 22904, USA
²⁷ Department of Physics and Astronomy, Rice University, 6100 Main Street, MS-108, Houston, TX 77005, USA
²⁸ NRC Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7, Canada
²⁹ Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2, Canada
³⁰ Department of Physics, National Sun Yat-Sen University, No. 70, Lien-Hai Road, Kaohsiung City 80424, Taiwan, ROC
³¹ Center of Astronomy and Gravitation, National Taiwan Normal University, Taipei 116, Taiwan, ROC
³² Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Apartado Postal 3-72, Morelia 58090, Michoacán, Mexico
³³ Black Hole Initiative at Harvard University, 20 Garden Street, Cambridge, MA 02138, USA
³⁴ David Rockefeller Center for Latin American Studies, Harvard University, 1730 Cambridge Street, Cambridge, MA 02138, USA
³⁵ National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
³⁶ Institute of Low Temperature Science, Hokkaido University, N19W8, Kita-ku, Sapporo, Hokkaido 060-0819, Japan
³⁷ Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
³⁸ Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
³⁹ Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Austin, Texas 78712, USA
⁴⁰ Steward Observatory, 933 N Cherry Ave., Tucson, AZ 85721, USA
⁴¹ Alma Mater Studiorum – Università di Bologna, Dipartimento di Fisica e Astronomia "Augusto Righi", Via Gobetti 93/2, I-40129, Bologna, Italy
⁴² Materials Science and Engineering, College of Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548, Japan
⁴³ Department of Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Rd., Minhang, Shanghai 200240, China
⁴⁴ SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Kanagawa 240-0193, Japan

^★ Corresponding author; tomoya.hirota@nao.ac.jp

Received: 10 December 2024
Accepted: 18 February 2025

Abstract

Context. While protostellar outflows are important in terms of mass accretion and angular momentum transport in star formation processes, high-resolution observations of outflows in protobinary systems are still sparse.

Aims. We aim to reveal outflow structures traced by millimeter SiO emission in a low-mass protobinary system, L483.

Methods. We observed the SiO (J = 5−4) line in L483 with the Atacama Large Millimeter/submillimeter Array (ALMA) as part of the large program FAUST (Fifty AU STudy of the chemistry in the disk/envelope systems of Solar-like protostars). The spatial and spectral resolutions were 0.39^′′×0.30^′′ (780 au×60 au) and 122 kHz (0.17 km s⁻¹ at 217 GHz), respectively. The spectral lines of SO, CS, and C¹⁸O were also used to study the physical and dynamical properties of the SiO emitting regions.

Results. Two SiO emission peaks are identified in the central part of L483, which have offsets of 100 au and 200 au toward the northeast (SiO-peak) and north (SiO-N), respectively, from the continuum peak. The SiO-peak shows only blueshifted emission with a broad linewidth of 5 km s⁻¹, while that of SiO-N corresponds to the systemic velocity. Furthermore, weak and compact SiO emission components are distributed up to 2400 au away from the continuum position. They have narrow linewidths of ∼1 km s⁻¹. One of these components is a blueshifted isolated emission feature, 2400 au northeast of the continuum peak, NE-cloud, located outside the east-west outflow lobes. The SiO abundances relative to H₂ are 10⁻¹⁰−10⁻⁹ and 10⁻¹⁰ in the central part and more widely distributed components, respectively. These are intermediate values between those of strongly shocked regions caused by high-velocity outflows and quiescent molecular clouds.

Conclusions. The central SiO emission could be interpreted as either two different outflows driven by both protostars or as an outflow ejected from one of the circumstellar disks in the binary system. The NE-cloud region is most likely explained as a remnant of an old shock produced by past outflow activity, as has been proposed for the low-mass protostar IRAS 15398–3359. The complex structures of the outflows traced by the SiO line could reflect dynamical processes of the newly formed protobinary system in L483.