A likely flyby of binary protostar Z CMa caught in action

Author(s): Ruobing Dong, Hauyu Baobab Liu, Nicolás Cuello, Christophe Pinte, Péter Ábrahám, Eduard Vorobyov, Jun Hashimoto, Ágnes Kóspál, Eugene Chiang, Michihiro Takami, Lei Chen, Michael Dunham, Misato Fukagawa, Joel Green, Yasuhiro Hasegawa, Thomas Henning, Yaroslav Pavlyuchenkov, Tae-Soo Pyo, Motohide Tamura
Abstract: Close encounters between young stellar objects in star-forming clusters are expected to markedly perturb circumstellar disks. Such events are witnessed in numerical simulations of star formation^1-3, but few direct observations of ongoing encounters have been made. Here we report sub-0.1″-resolution Atacama Large Millimeter/Submillimeter Array and Jansky Very Large Array observations towards the million-year-old binary protostar Z Canis Majoris in dust continuum and molecular line emission. A point source ~4,700 au from the binary has been discovered at both millimetre and centimetre wavelengths. It is located along the extension of a ~2,000 au streamer structure previously found in scattered light imaging, whose counterpart in dust and gas emission is also newly identified. Comparison with simulations shows signposts of a rare flyby event in action. Z CMa is a `double burster', as both binary components undergo accretion outbursts⁴, which may be facilitated by perturbations to the host disk by flybys^5-8.
Organisation(s): Department of Astrophysics
External organisation(s): University of Victoria, Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), No. 1, Section 4, Roosevelt Road, University of Grenoble Alpes, Monash University, Eötvös Loránd Research Network, Eötvös Loránd University Budapest, Southern Federal University, National Institutes of Natural Sciences (NINS), Max-Planck-Institut für Astronomie, University of California, Berkeley, State University of New York, Fredonia, National Astronomical Observatory of Japan, Space Telescope Science Institute, California Institute of Technology (Caltech), Russian Academy of Sciences, University of Tokyo
Journal: Nature Astronomy
Volume: 6
Pages: 331-338
No. of pages: 8
ISSN: 2397-3366
DOI: https://doi.org/10.48550/arXiv.2201.05617
Publication date: 01-2022
Peer reviewed: Yes
Austrian Fields of Science 2012: 103003 Astronomy, 103004 Astrophysics
Keywords
Portal url: https://ucrisportal.univie.ac.at/en/publications/f006eb81-8b23-4f5f-b002-810dede41b51

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