TY  - JOUR
A1  - Tootle, Samuel D.
A1  - Papenfort, Ludwig Jens
A1  - Most, Elias Roland
A1  - Rezzolla, Luciano
T1  - Quasi-universal behavior of the threshold mass in unequal-mass, spinning binary neutron star mergers
T2  - The Astrophysical Journal Letters
N2  - The lifetime of the remnant produced by the merger of two neutron stars can provide a wealth of information on the equation of state of nuclear matter and on the processes leading to the electromagnetic counterpart. Hence, it is essential to determine when this lifetime is the shortest, corresponding to when the remnant has a mass equal to the threshold mass, Mth, to prompt collapse to a black hole. We report on the results of more than 360 simulations of merging neutron-star binaries covering 40 different configurations differing in mass ratio and spin of the primary. Using this data, we have derived a quasi-universal relation for Mth and expressed its dependence on the mass ratio and spin of the binary. The new expression recovers the results of Koeppel et al. for equal-mass, irrotational binaries and reveals that Mth can increase (decrease) by 5% (10%) for binaries that have spins aligned (antialigned) with the orbital angular momentum and provides evidence for a nonmonotonic dependence of Mth on the mass asymmetry in the system. Finally, we extend to unequal masses and spinning binaries the lower limits that can be set on the stellar radii once a neutron star binary is detected, illustrating how the merger of an unequal-mass, rapidly spinning binary can significantly constrain the allowed values of the stellar radii.
KW  - Compact binary stars
KW  - General relativity
KW  - Gravitational collapse
KW  - Neutron stars
KW  - Compact objects
KW  - Stellar remnants
KW  - Black holes
KW  - Binary pulsars
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/62863
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-628631
SN  - 2041-8213
N1  - Unified Astronomy Thesaurus concepts:
Compact binary stars (283);
General relativity (641);
Gravitational collapse (662);
Neutron stars (1108);
Compact objects (288);
Stellar remnants (1627);
Black holes (162);
Binary pulsars (153)
N1  - L.R. acknowledges the support by the State of Hesse within the Research Cluster ELEMENTS (Project ID 500/10.006). E.R.M. acknowledges support from the Princeton Center for Theoretical Science, the Princeton Gravity Initiative, and the Institute for Advanced Study. The simulations were performed on HPE Apollo Hawk at the High Performance Computing Center Stuttgart (HLRS) under the grants BBHDISKS and BNSMIC, and on SuperMUC at the Leibniz Supercomputing Centre.
VL  - 922
IS  - 1
SP  - 1
EP  - 8
PB  - Institute of Physics Publ.
CY  - London
ER  -