Image Details
Caption: Figure 6.
Mass spectrum of BHs produced in primordial stellar binaries for Z = 0.002 and Z = 0.0002. The black line denotes the primary mass of GW231123 while the gray band indicates the 90% C.I.. The dashed lines show the maximum mass that a BH can attain as a product of single stellar evolution.
© 2025. The Author(s). Published by the American Astronomical Society.