Binaries at Low Metallicity: ranges for case A, B and C mass transfer

Understand

The evolution of single stars at low metallicity has attracted a large interest, while the effect of metallicity on binary evolution remains still relatively unexplored.

• We study the effect of metallicity on the number of binary systems that undergo different cases of mass transfer.
• We find that binaries at low metallicity are more likely to start transferring mass after the onset of central helium burning, often referred to as case C mass transfer.
• In other words, the donor star in a metal poor binary is more likely to have formed a massive CO core before the onset of mass transfer.