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
PY - 2020/9/29
Y1 - 2020/9/29
N2 - ABSTRACT 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 $\sim 30{{\ \rm per\ cent}}$ 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 - ABSTRACT 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 $\sim 30{{\ \rm per\ cent}}$ 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 - Astronomy and Astrophysics
KW - Space and Planetary Science
U2 - 10.1093/mnras/staa2177
DO - 10.1093/mnras/staa2177
M3 - Article
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 -