I am Rajika Kuruwita, an Independant Postdoc Fellow
at the Heidelberg Institute for Theoretical Studies

Abstract: Nearly half of all stars similar to our Sun are in binary or multiple systems1, which may affect the evolution of the stars and their protoplanetary disks during their earliest stages. NGC 1333-IRAS2A is a young, Class 0, low-mass protostellar system located in the Perseus molecular cloud2. It is known to drive two bipolar outflows that are almost perpendicular to each other on the sky3,4 and is resolved into binary components, VLA1 and VLA2, through long wavelength continuum observations5. Here we report spatially and spectrally resolved observations of a range of molecular species. We compare these to detailed magnetohydrodynamic simulations: the comparisons show that inhomogeneous accretion onto the circumstellar disks occurs in episodic bursts, driving a wobbling jet. We conclude that binarity and multiplicity in general strongly affect the properties of the emerging stars, as well as the physical and chemical structures of the protoplanetary disks and therefore potentially any emerging planetary systems

This animation demonstrates some of the episodic accretion observed at periastron during the early evolution of our simulated binaries. The left shows the total accretion of the binary system. The right panel shows top down density projections of thickness 100AU for the T2 (\(\mathcal{M} =\) 0.2) high resolution (L_ref=12) simulation. The projection is centred on the xy-plane. The thin lines show the magnetic field, and the arrows indicate the velocity field. Crosses show the position of the sink particles. The mass accreted by the sink particles in the simulations is indicated on the bottom left of each panel.

Acknowledgements: This paper makes use of the following ALMA data: ADS/JAO. ALMA#2018.1.00427.S. ALMA is a partnership of the European Southern Observatory (ESO; representing its member states), National Science Federation (NSF; United States) and National Institutes of Natural Sciences (NINS; Japan), together with the National Research Council Canada (NRC; Canada), Ministry of Science and Technology and Academia Sinica Institute of Astronomy and Astrophysics (MOST and ASIAA; Taiwan) and Korea Astronomy and Space Science Institute (KASI; Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, Associated Universities Inc./National Radio Astronomy Observatory (AUI/NRAO) and the National Astronomical Observatory of Japan (NAOJ). We acknowledge the Partnership for Advanced Computing in Europe (PRACE) for awarding us access to Curie at GENCI@CEA, France. Resources at the University of Copenhagen high-performance computing centre were used to carry out the data analysis and part of the modelling. J.K.J. acknowledges support from the Independent Research Fund Denmark (grant number DFF0135-00123B). R.L.K. received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 847523 ‘INTERACTIONS’. D.H. acknowledges support from the EACOA Fellowship from the East Asian Core Observatories Association. D.H. is supported by the Centre for Informatics and Computation in Astronomy (CICA) and grant number 110J0353I9 from the Ministry of Education of Taiwan. T.H. and R.L.K. acknowledge support from the Independent Research Fund Denmark through grant no. DFF8021-00350B. The research of L.E.K. is supported by a grant from VILLUM FONDEN (grant number 19127). Author contributions J.K.J., L.E.K. and E.A.B. designed the ALMA proposal. D.H. and J.K.J. calibrated and analysed the resulting observations. R.L.K. and T.H. performed and analysed the MHD simulations. All authors contributed to the comparisons and discussions as well as the writing of the paper.