Constraining the overcontact phase in massive binary evolution: I. Mixing in V382 Cyg, VFTS 352, and OGLE SMC-SC10 108086

被引：26

作者：

Abdul-Masih, Michael ^{[1
,2
]}

Sana, Hugues ^{[2
]}

Hawcroft, Calum ^{[2
]}

Almeida, Leonardo A. ^{[3
,4
]}

Brands, Sarah A. ^{[5
]}

de Mink, Selma E. ^{[5
,6
,7
]}

Justham, Stephen ^{[5
,8
]}

Langer, Norbert ^{[9
]}

Mahy, Laurent ^{[2
,10
]}

Marchant, Pablo ^{[2
]}

Menon, Athira ^{[5
]}

Puls, Joachim ^{[11
]}

Sundqvist, Jon ^{[2
]}

机构：

[1] European Southern Observ, Alonso de Cordova 3107, Santiago 19001, Chile

[2] Katholieke Univ Leuven, Inst Astrophys, Celestijnenlaan 200 D, B-3001 Leuven, Belgium

[3] Univ Fed Rio Grande do Norte, Escola Ciencias & Tecnol, BR-59072970 Natal, RN, Brazil

[4] Univ Estado Rio Grande do Norte, Dept Fis, BR-59610210 Mossoro, RN, Brazil

[5] Univ Amsterdam, Astron Inst Anton Pannekoek, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands

[6] Max Planck Inst Astrophys, Karl Schwarzschild Str 1, D-85740 Garching, Germany

[7] Harvard Univ, Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA

[8] Univ Chinese Acad Sci, Sch Astron & Space Sci, Beijing 100012, Peoples R China

[9] Univ Bonn, Argelander Inst Astron, Hugel 71, D-53121 Bonn, Germany

[10] Royal Observ Belgium, Ave Circulaire 3, B-1180 Brussels, Belgium

[11] LMU Munchen, Scheinerstr 1, D-81679 Munich, Germany

来源：

ASTRONOMY & ASTROPHYSICS | 2021年 / 651卷

基金：

比利时弗兰德研究基金会; 欧盟地平线“2020”; 欧洲研究理事会;

关键词：

stars: massive; binaries: spectroscopic; binaries: close; CHEMICALLY HOMOGENEOUS EVOLUTION; ATMOSPHERIC NLTE-MODELS; SMALL-MAGELLANIC-CLOUD; BLACK-HOLE MERGERS; VLT-FLAMES SURVEY; EARLY-TYPE STARS; ECLIPSING BINARIES; SPECTROSCOPIC ANALYSIS; BLUE STRAGGLERS; STELLAR MERGERS;

D O I：

10.1051/0004-6361/202040195

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Context. As potential progenitors of several exotic phenomena including gravitational wave sources, magnetic stars, and Be stars, close massive binary systems probe a crucial area of the parameter space in massive star evolution. Despite the importance of these systems, large uncertainties regarding the nature and efficiency of the internal mixing mechanisms still exist.Aims. We aim to provide robust observational constraints on the internal mixing processes by spectroscopically analyzing a sample of three massive overcontact binaries at different metallicities.Methods. Using optical phase-resolved spectroscopic data, we performed an atmosphere analysis using more traditional 1D techniques and the most recent 3D techniques. We compared and contrasted the assumptions and results of each technique and investigated how the assumptions affect the final derived atmospheric parameters.Results. We find that in all three cases, both components of a system are highly overluminous, indicating either efficient internal mixing of helium or previous nonconservative mass transfer. However, we do not find strong evidence of the helium or CNO surface abundance changes that are usually associated with mixing. Additionally, we find that in unequal-mass systems, the measured effective temperature and luminosity of the less massive component places it very close to the more massive component on the Hertzsprung-Russell diagram. These results were obtained independently using both of the techniques mentioned above. This suggests that these measurements are robust.Conclusions. The observed discrepancies between the temperature and the surface abundance measurements when compared to theoretical expectations indicate that additional physical mechanisms that have not been accounted for so far may be at play.

引用

页数：27