TY - JOUR
T1 - Be X-ray binaries in the SMC as indicators of mass-transfer efficiency
AU - Vinciguerra, Serena
AU - Neijssel, Coenraad J.
AU - Vigna-Gómez, Alejandro
AU - Mandel, Ilya
AU - Podsiadlowski, Philipp
AU - Maccarone, Thomas J.
AU - Nicholl, Matt
AU - Kingdon, Samuel
AU - Perry, Alice
AU - Salemi, Francesco
N1 - Publisher Copyright:
© 2020 The Author(s)
PY - 2020/11/1
Y1 - 2020/11/1
N2 - Be X-ray binaries (BeXRBs) consist of rapidly rotating Be stars with neutron star (NS) companions accreting from the circumstellar emission disc. We compare the observed population of BeXRBs in the Small Magellanic Cloud (SMC) with simulated populations of BeXRB-like systems produced with the COMPAS population synthesis code. We focus on the apparently higher minimal mass of Be stars in BeXRBs than in the Be population at large. Assuming that BeXRBs experienced only dynamically stable mass transfer, their mass distribution suggests that at least ∼ 30 per cent of the mass donated by the progenitor of the NS is typically accreted by the B-star companion. We expect these results to affect predictions for the population of double compact object mergers. A convolution of the simulated BeXRB population with the star formation history of the SMC shows that the excess of BeXRBs is most likely explained by this galaxy's burst of star formation ∼20-40 Myr ago.
AB - Be X-ray binaries (BeXRBs) consist of rapidly rotating Be stars with neutron star (NS) companions accreting from the circumstellar emission disc. We compare the observed population of BeXRBs in the Small Magellanic Cloud (SMC) with simulated populations of BeXRB-like systems produced with the COMPAS population synthesis code. We focus on the apparently higher minimal mass of Be stars in BeXRBs than in the Be population at large. Assuming that BeXRBs experienced only dynamically stable mass transfer, their mass distribution suggests that at least ∼ 30 per cent of the mass donated by the progenitor of the NS is typically accreted by the B-star companion. We expect these results to affect predictions for the population of double compact object mergers. A convolution of the simulated BeXRB population with the star formation history of the SMC shows that the excess of BeXRBs is most likely explained by this galaxy's burst of star formation ∼20-40 Myr ago.
KW - Be
KW - Gravitational waves
KW - Methods: data analysis
KW - Stars: emission-line
KW - Stars: evolution
KW - Stars: neutron
KW - X-rays: binaries
UR - http://www.scopus.com/inward/record.url?scp=85096797837&partnerID=8YFLogxK
U2 - 10.1093/mnras/staa2177
DO - 10.1093/mnras/staa2177
M3 - Article
AN - SCOPUS:85096797837
SN - 0035-8711
VL - 498
SP - 4705
EP - 4720
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -