A Bridge between Young Stars Formed by Gravitational Interaction

TL;DR

This paper presents observational evidence and simulations of a recent close encounter between two young stellar systems, revealing how such interactions can alter disk structures and impact star formation in clustered environments.

Contribution

It provides the first direct observational evidence of a dynamical flyby between young stars with disks, supported by hydrodynamical simulations.

Findings

Detection of a tidally stripped bridge between the stars

Identification of spiral structures in the disks

Simulation suggests closest approach occurred 15,000 years ago

Abstract

The majority of stars are born in clustered environments. In these environments, close encounters between young stars with planet-forming disks are expected to occur frequently. However, direct evidence of such interactions remains rare. Here, we report clear signatures of a recent dynamical interaction between the young stellar systems L1448 IRS3A and L1448 IRS3B. Millimeter wavelength observations reveal a distinct, tidally stripped bridge between the two systems. Together with previously reported spiral arm structures at the outer edge of the IRS3A disk and at the inner and outer regions of the IRS3B disk, these features imply that the systems are undergoing a dynamical flyby. Hydrodynamical simulations reproduce these features and suggest that the closest approach occurred about 15,000 yr ago. These findings offer rare insight into how stellar interactions can reshape disk structures and influence the formation of young multiple stellar systems.