The formation of ultra compact dwarf galaxies and massive globular clusters - Quasar-like objects to test for a variable stellar initial mass functionT. Jeřábková, P. Kroupa, J. Dabringhausen, M. Hilker and K. BekkiA&A, 608 (2017) A53DOI: https://doi.org/10.1051/0004-6361/201731240