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A likely flyby of binary protostar Z CMa caught in action

Nature Astronomy volume 6, pages 331–338 (2022)Cite this article

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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 formation1,2,3, 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 flybys5,6,7,8.

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Fig. 1: Observations of the Z CMa system.
Fig. 2: Integrated intensity (moment 0) maps of the 12CO (2–1), 13CO (2–1), C18O (2–1) and SO 3Σ 6(5)–5(4) transitions.
Fig. 3: Subaru H-band image and 13CO moment 0 map overlaid with the 5σ contours in ALMA 1.3 mm continuum emission and in JVLA 9 mm continuum emission.
Fig. 4: Comparing simulations with observations.

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Data availability

Raw ALMA data are publicly available via the ALMA archive https://almascience.eso.org/aq/ under project IDs 2016.1.00110.S and 2016.2.00168.S. Raw JVLA data are publicly available via the JVLA archive https://archive.nrao.edu/archive/advquery.jsp under project code 16B-080. Raw Keck data are publicly available via the KOA Data Access Service http://koa.ipac.caltech.edu/ under the programme ID U14N2. Final reduced and calibrated image files are available at https://doi.org/10.6084/m9.figshare.16915327.

Code availability

The Phantom code is made available at https://github.com/danieljprice/phantom by D. Price. The MCFOST code is made available at https://github.com/cpinte/mcfost by C.P.

References

  1. Offner, S. S. R., Klein, R. I. & McKee, C. F. Driven and decaying turbulence simulations of low-mass star formation: from clumps to cores to protostars. Astrophys. J. 686, 1174–1194 (2008).

    Article  ADS  Google Scholar 

  2. Bate, M. R. Stellar, brown dwarf and multiple star properties from a radiation hydrodynamical simulation of star cluster formation. Mon. Not. R. Astron. Soc. 419, 3115–3146 (2012).

    Article  ADS  Google Scholar 

  3. Kuruwita, R. L., Federrath, C. & Haugbølle, T. The dependence of episodic accretion on eccentricity during the formation of binary stars. Astron. Astrophys. 641, A59 (2020).

    Article  ADS  Google Scholar 

  4. Audard, M. et al. in Protostars and Planets VI (eds Beuther, H. et al.) 387–410 (University of Arizona Press, 2014).

  5. Pfalzner, S., Tackenberg, J. & Steinhausen, M. Accretion bursts in young stars driven by the cluster environment. Astron. Astrophys. 487, L45–L48 (2008).

    Article  ADS  Google Scholar 

  6. Cuello, N. et al. Flybys in protoplanetary discs: I. Gas and dust dynamics. Mon. Not. R. Astron. Soc. 483, 4114–4139 (2019).

    Article  ADS  Google Scholar 

  7. Dullemond, C. P. et al. Cloudlet capture by transitional disk and FU Orionis stars. Astron. Astrophys. 628, A20 (2019).

    Article  Google Scholar 

  8. Vorobyov, E. I., Elbakyan, V. G., Liu, H. B. & Takami, M. Distinguishing between different mechanisms of FU-Orionis-type luminosity outbursts. Astron. Astrophys. 647, A44 (2021).

    Article  ADS  Google Scholar 

  9. Hartmann, L. et al. Pre-main-sequence disk accretion in Z Canis Majoris. Astrophys. J. 338, 1001 (1989).

    Article  ADS  Google Scholar 

  10. Bonnefoy, M. et al. The 2008 outburst in the young stellar system Z CMa. III. Multi-epoch high-angular resolution images and spectra of the components in near-infrared. Astron. Astrophys. 597, A91 (2017).

    Article  Google Scholar 

  11. Hinkley, S. et al. High-resolution infrared imaging and spectroscopy of the Z Canis Majoris system during quiescence and outburst. Astrophys. J. 763, L9 (2013).

    Article  ADS  Google Scholar 

  12. Millan-Gabet, R. & Monnier, J. D. Discovery of a near-infrared jetlike feature in the Z Canis Majoris system. Astrophys. J. 580, L167–L170 (2002).

    Article  ADS  Google Scholar 

  13. Canovas, H. et al. The inner environment of Z Canis Majoris: high-contrast imaging polarimetry with NaCo. Astron. Astrophys. 578, L1 (2015).

    Article  ADS  Google Scholar 

  14. Alonso-Albi, T. et al. Circumstellar disks around Herbig Be stars. Astron. Astrophys. 497, 117–136 (2009).

    Article  ADS  Google Scholar 

  15. Liu, H. B. et al. Absence of significant cool disks in young stellar objects exhibiting repetitive optical outbursts. Astrophys. J. Lett. 816, L29 (2016).

    Article  ADS  Google Scholar 

  16. Liu, H. B. et al. A concordant scenario to explain FU Orionis from deep centimeter and millimeter interferometric observations. Astron. Astrophys. 602, A19 (2017).

    Article  Google Scholar 

  17. Li, J. I., Liu, H. B., Hasegawa, Y. & Hirano, N. Systematic analysis of spectral energy distributions and the dust opacity indices for class 0 young stellar objects. Astrophys. J. 840, 72 (2017).

    Article  ADS  Google Scholar 

  18. Liu, H. B. The anomalously low (sub)millimeter spectral indices of some protoplanetary disks may be explained by dust self-scattering. Astrophys. J. Lett. 877, L22 (2019).

    Article  ADS  Google Scholar 

  19. Kuffmeier, M., Calcutt, H. & Kristensen, L. E. The bridge: a transient phenomenon of forming stellar multiples. Sequential formation of stellar companions in filaments around young protostars. Astron. Astrophys. 628, A112 (2019).

    Article  ADS  Google Scholar 

  20. Lee, A. T., Offner, S. S. R., Kratter, K. M., Smullen, R. A. & Li, P. S. The formation and evolution of wide-orbit stellar multiples in magnetized clouds. Astrophys. J. 887, 232 (2019).

    Article  ADS  Google Scholar 

  21. Liu, H. B. et al. Circumstellar disks of the most vigorously accreting young stars. Sci. Adv. 2, e1500875 (2016).

    Article  ADS  Google Scholar 

  22. Dong, R., Vorobyov, E., Pavlyuchenkov, Y., Chiang, E. & Liu, H. B. Signatures of gravitational instability in resolved images of protostellar disks. Astrophys. J. 823, 141 (2016).

    Article  ADS  Google Scholar 

  23. Pfalzner, S. Spiral arms in accretion disk encounters. Astrophys. J. 592, 986–1001 (2003).

    Article  ADS  Google Scholar 

  24. Cuello, N. et al. Flybys in protoplanetary discs—II. Observational signatures. Mon. Not. R. Astron. Soc. 491, 504–514 (2020).

    Article  ADS  Google Scholar 

  25. Baraffe, I., Homeier, D., Allard, F. & Chabrier, G. New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit. Astron. Astrophys. 577, A42 (2015).

    Article  ADS  Google Scholar 

  26. Vorobyov, E. I. et al. The origin of tail-like structures around protoplanetary disks. Astron. Astrophys. 635, A196 (2020).

    Article  Google Scholar 

  27. Vorobyov, E. I., Steinrueck, M. E., Elbakyan, V. & Guedel, M. Formation of freely floating sub-stellar objects via close encounters. Astron. Astrophys. 608, A107 (2017).

    Article  ADS  Google Scholar 

  28. Winter, A. J., Clarke, C. J., Rosotti, G. & Booth, R. A. Protoplanetary disc response to distant tidal encounters in stellar clusters. Mon. Not. R. Astron. Soc. 475, 2314–2325 (2018).

    Article  ADS  Google Scholar 

  29. Kuffmeier, M., Dullemond, C. P., Reissl, S. & Goicovic, F. G. Misaligned disks induced by infall. Preprint at https://arxiv.org/abs/2110.04309 (2021).

  30. Dunham, M. M. & Vorobyov, E. I. Resolving the luminosity problem in low-mass star formation. Astrophys. J. 747, 52 (2012).

    Article  ADS  Google Scholar 

  31. Meyer, D. M. A. et al. Burst occurrence in young massive stellar objects. Mon. Not. R. Astron. Soc. 482, 5459–5476 (2019).

    Article  ADS  Google Scholar 

  32. Vorobyov, E. I. Ejection of gaseous clumps from gravitationally unstable protostellar disks. Astron. Astrophys. 590, A115 (2016).

    Article  ADS  Google Scholar 

  33. Kratter, K. M., Murray-Clay, R. A. & Youdin, A. N. The runts of the litter: why planets formed through gravitational instability can only be failed binary stars. Astrophys. J. 710, 1375–1386 (2010).

    Article  ADS  Google Scholar 

  34. Basu, S. & Vorobyov, E. I. A hybrid scenario for the formation of brown dwarfs and very low mass stars. Astrophys. J. 750, 30 (2012).

    Article  ADS  Google Scholar 

  35. Grady, C. A. et al. Hubble Space Telescope Space Telescope Imaging Spectrograph coronagraphic imaging of the Herbig Ae star AB Aurigae. Astrophys. J. Lett. 523, L151–L154 (1999).

    Article  ADS  Google Scholar 

  36. Fukagawa, M. et al. Spiral structure in the circumstellar disk around AB Aurigae. Astrophys. J. Lett. 605, L53–L56 (2004).

    Article  ADS  Google Scholar 

  37. Pineda, J. E. et al. A protostellar system fed by a streamer of 10,500 au length. Nat. Astron. 4, 1158–1163 (2020).

    Article  ADS  Google Scholar 

  38. Ginski, C. et al. Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): late infall causing disk misalignment and dynamic structures in SU Aur. Astrophys. J. Lett. 908, L25 (2021).

    Article  ADS  Google Scholar 

  39. Huang, J. et al. Molecules with ALMA at Planet-forming Scales (MAPS) XIX. Spiral arms, a tail, and diffuse structures traced by CO around the GM Aur disk. Astrophys. J. Suppl. Ser. 257, 28 (2021).

    Article  ADS  Google Scholar 

  40. Brown, M. E., Trujillo, C. & Rabinowitz, D. Discovery of a candidate Inner Oort Cloud planetoid. Astrophys. J. 617, 645–649 (2004).

    Article  ADS  Google Scholar 

  41. Schwamb, M. E., Brown, M. E., Rabinowitz, D. L. & Ragozzine, D. Properties of the distant Kuiper Belt: results from the Palomar Distant Solar System Survey. Astrophys. J. 720, 1691–1707 (2010).

    Article  ADS  Google Scholar 

  42. Duchêne, G. & Kraus, A. Stellar multiplicity. Annu. Rev. Astron. Astrophys. 51, 269–310 (2013).

    Article  ADS  Google Scholar 

  43. Lindegren, L. et al. Gaia Early Data Release 3. The astrometric solution. Astron. Astrophys. 649, A2 (2021).

    Article  Google Scholar 

  44. Clariá, J. J. A study of the stellar association Canis Major OB 1. Astron. Astrophys. 37, 229–236 (1974).

    ADS  Google Scholar 

  45. Kaltcheva, N. T. & Hilditch, R. W. The distribution of bright OB stars in the Canis Major–Puppis–Vela region of the Milky Way. Mon. Not. R. Astron. Soc. 312, 753–768 (2000).

    Article  ADS  Google Scholar 

  46. Takami, M. et al. Near-infrared high-resolution imaging polarimetry of FU Ori-type objects: toward a unified scheme for low-mass protostellar evolution. Astrophys. J. 864, 20 (2018).

    Article  ADS  Google Scholar 

  47. Herbig, G. H. & Bell, K. R. Third Catalog of Emission-Line Stars of the Orion Population (Lick Observatory, 1988).

  48. Ikeda, H. et al. Sequential star formation in a cometary globule (BRC37) of IC1396. Astron. J. 135, 2323–2335 (2008).

    Article  ADS  Google Scholar 

  49. Fernandes, B., Gregorio-Hetem, J., Montmerle, T. & Rojas, G. Spectroscopic characterization of X-ray emitting young stars associated with the Sh 2-296 nebula. Mon. Not. R. Astron. Soc. 448, 119–134 (2015).

    Article  ADS  Google Scholar 

  50. Ducourant, C. et al. Pre-main sequence star proper motion catalogue. Astron. Astrophys. 438, 769–778 (2005).

    Article  ADS  Google Scholar 

  51. McMullin, J. P., Waters, B., Schiebel, D., Young, W. & Golap, K. CASA architecture and applications. In Astronomical Data Analysis Software and Systems XVI (eds Shaw, R. A. et al.) 127 (Astronomical Society of the Pacific Conference Series Vol. 376, 2007).

  52. Sault, R. J., Teuben, P. J. & Wright, M. C. H. A retrospective view of MIRIAD. In Astronomical Data Analysis Software and Systems IV (eds Shaw, R. A. et al.) 433 (Astronomical Society of the Pacific Conference Series Vol. 77, 1995).

  53. Beckwith, S. V. W., Sargent, A. I., Chini, R. S. & Guesten, R. A survey for circumstellar disks around young stellar objects. Astron. J. 99, 924–945 (1990).

    Article  ADS  Google Scholar 

  54. Price, D. J. et al. Phantom: a smoothed particle hydrodynamics and magnetohydrodynamics code for astrophysics. Publ. Astron. Soc. Aust. 35, e031 (2018).

    Article  ADS  Google Scholar 

  55. Lodato, G. & Price, D. J. On the diffusive propagation of warps in thin accretion discs. Mon. Not. R. Astron. Soc. 405, 1212–1226 (2010).

    ADS  Google Scholar 

  56. Dong, R., Fung, J. & Chiang, E. How spirals and gaps driven by companions in protoplanetary disks appear in scattered light at arbitrary viewing angles. Astrophys. J. 826, 75 (2016).

    Article  ADS  Google Scholar 

  57. Bate, M. R., Bonnell, I. A. & Price, N. M. Modelling accretion in protobinary systems. Mon. Not. R. Astron. Soc. 277, 362–376 (1995).

    Article  ADS  Google Scholar 

  58. Pinte, C., Ménard, F., Duchêne, G. & Bastien, P. Monte Carlo radiative transfer in protoplanetary disks. Astron. Astrophys. 459, 797–804 (2006).

    Article  ADS  Google Scholar 

  59. Pinte, C. et al. Benchmark problems for continuum radiative transfer. High optical depths, anisotropic scattering, and polarisation. Astron. Astrophys. 498, 967–980 (2009).

    Article  ADS  Google Scholar 

  60. Siess, L., Dufour, E. & Forestini, M. An internet server for pre-main sequence tracks of low- and intermediate-mass stars. Astron. Astrophys. 358, 593–599 (2000).

    ADS  Google Scholar 

  61. Allard, F., Homeier, D. & Freytag, B. Models of very-low-mass stars, brown dwarfs and exoplanets. Philos. Trans. R. Soc. A 370, 2765–2777 (2012).

    Article  ADS  Google Scholar 

  62. Vorobyov, E. I. & Elbakyan, V. G. Gravitational fragmentation and formation of giant protoplanets on orbits of tens of au. Astron. Astrophys. 618, A7 (2018).

    Article  Google Scholar 

  63. Weingartner, J. C. & Draine, B. T. Dust grain-size distributions and extinction in the Milky Way, Large Magellanic Cloud, and Small Magellanic Cloud. Astrophys. J. 548, 296–309 (2001).

    Article  ADS  Google Scholar 

  64. Forgan, D. & Rice, K. Stellar encounters in the context of outburst phenomena. Mon. Not. R. Astron. Soc. 402, 1349–1356 (2010).

    Article  ADS  Google Scholar 

  65. Takami, M. et al. High-contrast near-infrared imaging polarimetry of the protoplanetary disk around RY Tau. Astrophys. J. 772, 145 (2013).

    Article  ADS  Google Scholar 

  66. Terada, H. et al. Detection of water ice in edge-on protoplanetary disks: HK Tauri B and HV Tauri C. Astrophys. J. 667, 303–307 (2007).

    Article  ADS  Google Scholar 

  67. Frost, A. J., Oudmaijer, R. D., de Wit, W. J. & Lumsden, S. L. A multi-scale exploration of a massive young stellar object. A transition disk around G305.20+0.21? Astron. Astrophys. 625, A44 (2019).

    Article  Google Scholar 

  68. Gerin, M. et al. Evidence for disks at an early stage in class 0 protostars? Astron. Astrophys. 606, A35 (2017).

    Article  Google Scholar 

  69. Gaudel, M. et al. Angular momentum profiles of Class 0 protostellar envelopes. Astron. Astrophys. 637, A92 (2020).

    Article  Google Scholar 

  70. Flores-Rivera, L. et al. Physical and chemical structure of the disk and envelope of the class 0/I protostar L1527. Astrophys. J. 908, 108 (2021).

    Article  ADS  Google Scholar 

  71. Cabrit, S., Pety, J., Pesenti, N. & Dougados, C. Tidal stripping and disk kinematics in the RW Aurigae system. Astron. Astrophys. 452, 897–906 (2006).

    Article  ADS  Google Scholar 

  72. Dai, F., Facchini, S., Clarke, C. J. & Haworth, T. J. A tidal encounter caught in the act: modelling a star-disc fly-by in the young RW Aurigae system. Mon. Not. R. Astron. Soc. 449, 1996–2009 (2015).

    Article  ADS  Google Scholar 

  73. Kurtovic, N. T. et al. The Disk Substructures at High Angular Resolution Project (DSHARP). IV. Characterizing substructures and interactions in disks around multiple star systems. Astrophys. J. 869, L44 (2018).

    Article  ADS  Google Scholar 

  74. Ménard, F. et al. Ongoing flyby in the young multiple system UX Tauri. Astron. Astrophys. 639, L1 (2020).

    Article  ADS  Google Scholar 

  75. Zapata, L. A. et al. Tidal interaction between the UX Tauri A/C disk system revealed by ALMA. Astrophys. J. 896, 132 (2020).

    Article  ADS  Google Scholar 

  76. Rodriguez, J. E. et al. Multiple stellar flybys sculpting the circumstellar architecture in RW Aurigae. Astrophys. J. 859, 150 (2018).

    Article  ADS  Google Scholar 

  77. Dong, R. et al. An M dwarf companion and its induced spiral arms in the HD 100453 protoplanetary disk. Astrophys. J. Lett. 816, L12 (2016).

    Article  ADS  Google Scholar 

  78. Wagner, K. et al. The orbit of the companion to HD 100453A: binary-driven spiral arms in a protoplanetary disk. Astrophys. J. 854, 130 (2018).

    Article  ADS  Google Scholar 

  79. van der Plas, G. et al. ALMA study of the HD 100453 AB system and the tidal interaction of the companion with the disk. Astron. Astrophys. 624, A33 (2019).

    Article  Google Scholar 

  80. Rosotti, G. P. et al. Spiral arms in the protoplanetary disc HD100453 detected with ALMA: evidence for binary–disc interaction and a vertical temperature gradient. Mon. Not. R. Astron. Soc. 491, 1335–1347 (2020).

    Article  ADS  Google Scholar 

  81. Liljeström, T. & Olofsson, G. Evidence for infall toward Z Canis Majoris from radio and near-infrared spectroscopy. Astrophys. J. 478, 381–394 (1997).

    Article  ADS  Google Scholar 

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Acknowledgements

We thank C.-H. Kim, J. Lee and H. Deng for helpful discussions. R.D. would like to thank L. Xu for support and encouragement in the period of this work. R.D. acknowledges financial support provided by the Natural Sciences and Engineering Research Council of Canada through a Discovery Grant, as well as the Alfred P. Sloan Foundation through a Sloan Research Fellowship. N.C. acknowledges support from the European Union’s Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement 210021. H.B.L. acknowledges support from the Ministry of Science and Technology (MoST) of Taiwan (grant 108-2112-M-001-002-MY3). E.V. acknowledges support from the Russian Fund for Fundamental Research, Russian–Taiwanese project 19-52-52011. Y.H. is supported by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. A.K. and L.C. acknowledge support from the European Research Council under the European Union’s Horizon 2020 research and innovation programme, grant agreement 716155 (SACCRED). L.C. is supported by the Hungarian OTKA grant K132406. M. Takami is supported by the Ministry of Science and Technology (MoST) of Taiwan (grants 106-2119-M-001-026-MY3 and 109-2112-M-001-019). H.B.L. and M.T. and are supported by MoST of Taiwan 108-2923-M-001-006-MY3 for the Taiwanese–Russian collaboration project. The Geryon cluster at the Centro de Astro-Ingenieria UC was extensively used for the calculations performed in this paper. BASAL CATA PFB-06, the Anillo ACT-86, FONDEQUIP AIC-57 and QUIMAL 130008 provided funding for several improvements to the Geryon cluster. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.00110.S and #2016.2.00168.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan) and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, auI/NRAO and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Author information

Authors and Affiliations

  1. Department of Physics & Astronomy, University of Victoria, Victoria, British Columbia, Canada

    Ruobing Dong

  2. Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Republic of China

    Hauyu Baobab Liu & Michihiro Takami

  3. Université Grenoble Alpes, CNRS, IPAG, Grenoble, France

    Nicolás Cuello

  4. Monash Centre for Astrophysics (MoCA) and School of Physics and Astronomy, Monash University, Clayton, Victoria, Australia

    Christophe Pinte

  5. Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH), Budapest, Hungary

    Péter Ábrahám, Ágnes Kóspál & Lei Chen

  6. Institute of Physics, ELTE Eötvös Loránd University, Budapest, Hungary

    Péter Ábrahám & Ágnes Kóspál

  7. Department of Astrophysics, University of Vienna, Vienna, Austria

    Eduard Vorobyov

  8. Research Institute of Physics, Southern Federal University, Rostov-on-Don, Russia

    Eduard Vorobyov

  9. Astrobiology Center, National Institutes of Natural Sciences, Mitaka, Tokyo, Japan

    Jun Hashimoto & Motohide Tamura

  10. Max-Planck-Institut für Astronomie, Heidelberg, Germany

    Ágnes Kóspál & Thomas Henning

  11. Department of Astronomy, University of California at Berkeley, Berkeley, CA, USA

    Eugene Chiang

  12. Department of Physics, State University of New York at Fredonia, Fredonia, NY, USA

    Michael Dunham

  13. National Astronomical Observatory of Japan, Mitaka, Tokyo, Japan

    Misato Fukagawa & Motohide Tamura

  14. Space Telescope Science Institute (STScI), Baltimore, MD, USA

    Joel Green

  15. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA

    Yasuhiro Hasegawa

  16. Institute of Astronomy, Russian Academy of Sciences, Moscow, Russia

    Yaroslav Pavlyuchenkov

  17. Subaru Telescope, National Astronomical Observatory of Japan, National Institutes of Natural Sciences, Hilo, HI, USA

    Tae-Soo Pyo

  18. Department of Astronomy, The University of Tokyo, Tokyo, Japan

    Motohide Tamura

Authors
  1. Ruobing Dong
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  2. Hauyu Baobab Liu
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  3. Nicolás Cuello
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  5. Péter Ábrahám
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  6. Eduard Vorobyov
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  7. Jun Hashimoto
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  8. Ágnes Kóspál
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  9. Eugene Chiang
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  10. Michihiro Takami
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  12. Michael Dunham
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Contributions

R.D. led the ALMA proposals. H.B.L. led the JVLA proposal and processed the ALMA and JVLA data. N.C. and C.P. performed the hydrodynamics and radiative transfer simulations. R.D., H.B.L., N.C. and C.P. wrote the manuscript. All coauthors provided input to the observational proposals and/or the manuscript.

Corresponding authors

Correspondence to Ruobing Dong, Hauyu Baobab Liu, Nicolás Cuello or Christophe Pinte.

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The authors declare that they have no competing interests.

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Nature Astronomy thanks Thomas Haworth, Michael Kuffmeier and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Extended data

Extended Data Fig. 1 Integrated intensity maps of the 12CO (2-1), 13CO (2-1), C18O (2-1), and SO 3Σ 6(5)-5(4) transitions.

The beam size (0.19″ × 0.18″; P.A.=88∘) is marked at the lower left corner. The Robust=0 weighted 224 GHz continuum image (beam size 0″. 075 × 0″. 047; P.A.=65∘) is shown in green contours at 0.13 and 1.3 mJy beam−1 levels (5 and 50 × the root mean square noises) to highlight the four compact continuum sources. The ALMA/VLA source C is labeled.

Extended Data Fig. 2 Moment-1 maps (intensity-weighted mean velocity) of the gas observations.

The Robust=0 weighted 224 GHz continuum image (beam size 0″. 075 × 0″. 047; P.A.=65∘) is shown in white contours at 0.13 and 1.3 mJy beam−1 levels (5 and 50 × the root mean square noises). The systematic velocity is ~ 14 km/s (ref. 81). The ALMA/VLA source C is labeled.

Extended Data Fig. 3 Gaussian fitting of point-like components detected around Z CMa.

Gaussian fittings may be confused by extended dust emission. While we treat the Gaussian fitted flux as the total flux and use it in dust mass estimates, the true total flux from each source may be in between the peak intensity and the Gaussian fitted flux. (a) Gaussian deconvolved major axis FWHM. (b) Gaussian deconvolved minor axis FWHM. (c) Gaussian deconvolved position angle. (d) Only detected from the Robust = 2 weighted image, with beam=100 × 66 mas (P.A.=19∘). (e) Gaussian fitting results indicate that the source is consistent with a δ function with non-detectable size.

Extended Data Fig. 4 Sketch of the flyby simulation geometry.

The perturber’s orbital plane is in orange. The plane of the initial circumprimary disk is in blue. The primary spiral pointing towards the perturber is in solid red and is in the plane of the perturber. The secondary spiral is in dashed red and in the plane of the circumprimary disk. The line of sight is in the z direction.

Extended Data Fig. 5 Keck/NIRC2 H-band archive data of Z CMa.

The data were taken in 2005 Oct 21. White circle indicates the position of the point source C.

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Dong, R., Liu, H.B., Cuello, N. et al. A likely flyby of binary protostar Z CMa caught in action. Nat Astron 6, 331–338 (2022). https://doi.org/10.1038/s41550-021-01558-y

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