The tidal tails of open star clusters produced by early gas expulsion

摘要

We investigate, for the first time, the formation and evolution of the tidal tail released from a young Pleiades-like star cluster due to expulsion of primordial gas in a realistic gravitational field of the Galaxy. The tidal tails (as well as clusters) are integrated by NBODY6 from their embedded phase for more than 300 Myr. We vary the star formation efficiency (SFE) from 33% to 100% and the timescales of gas expulsion as free parameters, and provide predictions for the morphology and kinematics of the evolved tail for each of the models. The resulting tail properties are intended for comparison with Gaia measurements, where an inverse analysis of our findings might constrain some of the poorly understood conditions and processes in embedded star clusters during the gas phase and gas expulsion.