Evolution of AM CVn Binaries with White Dwarf Donors

Abstract The evolution and the stability of mass transfer CO+He white dwarf (WD) binaries are not well understood. Observationally they may emerge as AM CVn important gravitational wave (GW) emitters. In this work, we have modeled double WD with accretor masses 0.50–1.30 M ⊙ donor 0.17–0.45 using detailed stellar code mesa . We find that same but different is very similar larger He maximum rates smaller minimum orbital periods. also demonstrate GW signal from can be detected by spaceborne observatories, such LISA TianQin. There a linear relation between frequency during phase. our calculation, all dynamically stable transfer, which previous studies. threshold Eddington-limited for given lower than Assuming binary enter common envelope if rate exceeds burning He, provide new criterion WDs surviving below Eddington limit. Finally, some systems oxygen–neon (ONe) in calculation evolve into detached consisting neutron stars extremely low-mass WDs, further ultracompact X-ray binaries.