TY - JOUR

T1 - Impact of massive binary star and cosmic evolution on gravitational wave observations - II. Double compact object rates and properties

AU - Broekgaarden, Floor S.

AU - Berger, Edo

AU - Stevenson, Simon

AU - Justham, Stephen

AU - Mandel, Ilya

AU - Chruslinska, Martyna

AU - van Son, Lieke A. C.

AU - Wagg, Tom

AU - Vigna-Gomez, Alejandro

AU - de Mink, Selma E.

AU - Chattopadhyay, Debatri

AU - Neijssel, Coenraad J.

PY - 2022/10/3

Y1 - 2022/10/3

N2 - Making the most of the rapidly increasing population of gravitational-wave detections of black hole (BH) and neutron star (NS) mergers requires comparing observations with population synthesis predictions. In this work, we investigate the combined impact from the key uncertainties in population synthesis modelling of the isolated binary evolution channel: the physical processes in massive binary-star evolution and the star formation history as a function of metallicity, Z, and redshift z, S(Z,z). Considering these uncertainties, we create 560 different publicly available model realizations and calculate the rate and distribution characteristics of detectable BHBH, BHNS, and NSNS mergers. We find that our stellar evolution and S(Z,z) variations can combined impact the predicted intrinsic and detectable merger rates by factors in the range 10(2)-10(4). We find that BHBH rates are dominantly impacted by S(Z,z) variations, NSNS rates by stellar evolution variations and BHNS rates by both. We then consider the combined impact from all uncertainties considered in this work on the detectable mass distribution shapes (chirp mass, individual masses, and mass ratio). We find that the BHNS mass distributions are predominantly impacted by massive binary-star evolution changes. For BHBH and NSNS, we find that both uncertainties are important. We also find that the shape of the delay time and birth metallicity distributions are typically dominated by the choice of S(Z,z) for BHBH, BHNS, and NSNS. We identify several examples of robust features in the mass distributions predicted by all 560 models, such that we expect more than 95 per cent of BHBH detections to contain a BH greater than or similar to 8 M-circle dot and have mass ratios less than or similar to 4. Our work demonstrates that it is essential to consider a wide range of allowed models to study double compact object merger rates and properties. Conversely, larger observed samples could allow us to decipher currently unconstrained stages of stellar and binary evolution.

AB - Making the most of the rapidly increasing population of gravitational-wave detections of black hole (BH) and neutron star (NS) mergers requires comparing observations with population synthesis predictions. In this work, we investigate the combined impact from the key uncertainties in population synthesis modelling of the isolated binary evolution channel: the physical processes in massive binary-star evolution and the star formation history as a function of metallicity, Z, and redshift z, S(Z,z). Considering these uncertainties, we create 560 different publicly available model realizations and calculate the rate and distribution characteristics of detectable BHBH, BHNS, and NSNS mergers. We find that our stellar evolution and S(Z,z) variations can combined impact the predicted intrinsic and detectable merger rates by factors in the range 10(2)-10(4). We find that BHBH rates are dominantly impacted by S(Z,z) variations, NSNS rates by stellar evolution variations and BHNS rates by both. We then consider the combined impact from all uncertainties considered in this work on the detectable mass distribution shapes (chirp mass, individual masses, and mass ratio). We find that the BHNS mass distributions are predominantly impacted by massive binary-star evolution changes. For BHBH and NSNS, we find that both uncertainties are important. We also find that the shape of the delay time and birth metallicity distributions are typically dominated by the choice of S(Z,z) for BHBH, BHNS, and NSNS. We identify several examples of robust features in the mass distributions predicted by all 560 models, such that we expect more than 95 per cent of BHBH detections to contain a BH greater than or similar to 8 M-circle dot and have mass ratios less than or similar to 4. Our work demonstrates that it is essential to consider a wide range of allowed models to study double compact object merger rates and properties. Conversely, larger observed samples could allow us to decipher currently unconstrained stages of stellar and binary evolution.

KW - gravitational waves

KW - stars: evolution

KW - (transients:) black hole - neutron star mergers

KW - BLACK-HOLE BINARIES

KW - PAIR-INSTABILITY SUPERNOVAE

KW - X-RAY BINARIES

KW - NEUTRON-STAR

KW - COMMON ENVELOPE

KW - STELLAR EVOLUTION

KW - CORE-COLLAPSE

KW - MERGER RATES

KW - METALLICITY

KW - PROGENITORS

U2 - 10.1093/mnras/stac1677

DO - 10.1093/mnras/stac1677

M3 - Journal article

VL - 516

SP - 5737

EP - 5761

JO - Royal Astronomical Society. Monthly Notices

JF - Royal Astronomical Society. Monthly Notices

SN - 0035-8711

IS - 4

ER -