Super-Eddington accretion as a possible scenario to form GW190425

On 2019 April 25, the LIGO/Virgo Scientific Collaboration detected a compact binary coalescence, GW190425. Under the assumption of the binary neutron star (BNS), the total mass of 3.4(-0.1)(+0.3) M-circle dot lies five standard deviations away from the known Galactic population mean. In the standard common envelope scenario, the immediate progenitor of GW190425 is a close binary system composed of an NS and a He-rich star. With the detailed binary evolutionary modelling, we find that in order to reproduce GW190425-like events, super-Eddington accretion (e.g. 1,000 (M)over dot(Edd)) from a He-rich star onto the first-born NS with a typical mass of 1.33M(circle dot) via stable Case BB mass transfer (MT) is necessarily required. Furthermore, the immediate progenitors should potentially have an initial mass of M-ZamsHe in a range of 3.0-3.5M(circle dot) and an initial orbital period of P-init from 0.08d to 0.12d, respectively. The corresponding mass accreted onto NSs via stable Case BB MT phase varies from 0.70 M-circle dot to 0.77 M-circle dot. After the formation of the second-born NS, the BNSs are expected to be merged due to gravitational wave emission from similar to 11Myr to similar to 190Myr.