Shima, KazuhiroTasker, Elizabeth J.Federrath, ChristophHabe, Asao2021-12-100004-6264http://hdl.handle.net/1885/255072We investigate star formation occurring in idealized giant molecular clouds, comparing structures that evolve in isolation versus those undergoing a collision. Two different collision speeds are investigated and the impact of photoionizing radiation from the stars is determined. We find that a colliding system leads to more massive star formation both with and without the addition of feedback, raising overall star formation efficiencies (SFE) by a factor of 10 and steepening the high-mass end of the stellar mass function. This rise in SFE is due to increased turbulent compression during the cloud collision. While feedback can both promote and hinder star formation in an isolated system, it increases the SFE by approximately 1.5 times in the colliding case when the thermal speed of the resulting H II regions matches the shock propagation speed in the collision.EJT was partially supported by JSPS Grant-in-Aid for Scientific Research Number 15K0514. CF acknowledges funding provided by the Australian Research Council’s Discovery Projects (grants DP130102078 and DP150104329). CF thanks the Juelich Supercomputing Centre (grant hhd20), the Leibniz Rechenzentrum and the Gauss Centre for Supercomputing (grants pr32lo, pr48pi and GCS Large-scale project 10391), the Partnership for Advanced Computing in Europe (PRACE grant pr89mu), and the Australian National Computational Infrastructure (grant ek9), as well as the Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia.application/pdfen-AU© The Author(s) 2017. Published by Oxford University Press on behalf of the Astronomical Society of JapanISM: cloudsmethods: numericalstars: formation201810.1093/pasj/psx1242020-11-23