Detailed models of interacting short-period massive binary stars

Abstract

Context. The majority of massive stars are part of binary systems. In about a quarter of these, the companions are so close that mass transfer occurs while they undergo core hydrogen burning, first on the thermal and then on the nuclear timescale. The nuclear timescale mass transfer leads to observational counterparts: the semi-detached so-called massive Algol binaries. These systems may provide urgently needed tests of the physics of mass transfer. However, comprehensive model predictions for these systems are sparse. Aims. We use a large grid of detailed evolutionary models of short-period massive binaries and follow-up population synthesis calculations to derive probability distributions of the observable properties of massive Algols and their descendants. Methods. Our results are based on ∼10 000 binary model sequences calculated with the stellar evolution code MESA, using a metallicity suitable for the Large Magellanic Cloud (LMC), covering initial donor masses between 10 M⊙ and 40 M⊙ and initial orbital periods above 1.4 d. These models include internal differential rotation and magnetic angular momentum transport, non-conservative mass and angular momentum transfer between the binary components, and time-dependent tidal coupling. Results. Our models imply ∼30, or ∼3% of the ∼1000, core hydrogen burning O-star binaries in the LMC to be currently in the semi-detached phase. Our donor models are up to 25 times more luminous than single stars of an identical mass and effective temperature, which agrees with the observed Algols. A comparison of our models with the observed orbital periods and mass ratios implies rather conservative mass transfer in some systems, while a very inefficient one in others. This is generally well reproduced by our spin-dependent mass transfer algorithm, except for the lowest considered masses. The observations reflect the slow increase of the surface nitrogen enrichment of the donors during the semi-detached phase all the way to CNO equilibrium. We also investigate the properties of our models after core hydrogen depletion of the donor star, when these models correspond to Wolf-Rayet or helium+OB star binaries. Conclusions. A dedicated spectroscopic survey of massive Algol systems may allow to derive the dependence of the efficiency of thermal timescale mass transfer on the binary parameters, as well as the efficiency of semiconvective mixing in the stellar interior. This would be a crucial step towards reliable binary models up to the formation of supernovae and compact objects.

Identifying quiescent compact objects in massive Galactic single-lined spectroscopic binaries

“…They include (i) chemically homogeneous evolution (CHE, Maeder 1987;Langer 1992;Martins et al 2013) in very massive short-period stellar binaries, which pre-vents mass transfer and allows compact MS binaries to directly evolve into compact BH binaries Marchant et al 2016;Abdul-Masih et al 2019;du Buisson et al 2020;Riley et al 2021;Abdul-Masih et al 2021;Menon et al 2021), (ii) evolution through a common-envelope phase (e.g. Paczynski 1976;van den Heuvel 1976;Tutukov & Yungelson 1993;Belczynski et al 2002Belczynski et al , 2016Giacobbo & Mapelli 2018), even though current theoretical predictions are highly uncertain and observational constraints of these specific stages are missing, (iii) stable mass transfer (van den Heuvel et al 2017;Neijssel et al 2019;Bavera et al 2020;Marchant et al 2021;Menon et al 2021;Sen et al 2022), and (iv) Population III stars (Belczynski et al 2004;Kinugawa et al 2014;Inayoshi et al 2017).…”

The Tarantula Massive Binary Monitoring

“…Short-period (P ≲ 10 d) binaries specifically entail the danger of having undergone an interaction in the past, as testified by short-period Algol-like systems (e.g. Mahy et al 2020b,a;Janssens et al 2021;Sen et al 2022). In contrast, single-lined spectroscopic binaries (SB1) are dominated by binaries with more extreme mass ratios and longer periods, where a past binary interaction can be excluded in the case of two non-degenerate components.…”

The Common Envelope Evolution Outcome—A Case Study on Hot Subdwarf B Stars

“…Besides the BPS studies on low-mass binary stars (e.g., Lagos et al 2020;Hernandez et al 2021;Leiner & Geller 2021), such studies for massive binary stars have increased recently. For examples, studies cover pulsating ultraluminous X-ray sources (Misra et al 2020), close double neutron star sources (Vigna-Gómez et al 2020;Kruckow 2020;Mandel et al 2021), neutron star binaries through accretioninduced collapse (Wang & Liu 2020), compact intermediatemass black hole X-ray binaries (Chen 2020), luminous red novae (Blagorodnova et al 2021), rapidly rotating Be binaries (El-Badry & Quataert 2021), short-period massive binary stars (Sen et al 2022), Type II supernova progenitors (Zapartas et al 2021), and black hole or neutron star binaries (recent papers like Shao & Li 2021;Mandel & Broekgaarden 2022). Marchant et al (2021) focuses on 30 M e models, while Kruckow et al (2016) focuses on 80-88 M e models.…”