Ancestral Black Holes of Binary Merger GW190521

Understand

GW190521 was the most massive black hole merger discovered by LIGO/Virgo so far, with masses in tension with stellar evolution models.

• A possible explanation of such heavy black holes is that they themselves are the remnants of previous mergers of lighter black holes.
• Here we estimate the masses of the ancestral black holes of GW190521, assuming it is the end product of previous mergers.
• We find that the heaviest parental black holes has a mass of $62^{+21}_{-19}$ M$_\odot$ (90% credible level).