Hot subdwarf B stars with neutron star components: II. Binary population synthesis
文献类型:期刊论文
作者 | Wu Y(吴优)1,2,3; Chen XF(陈雪飞)1,2,4; Chen HL(陈海亮)1,2,4; Li ZW(李振威)1,2,3; Han ZW(韩占文)1,2,4 |
刊名 | ASTRONOMY & ASTROPHYSICS |
出版日期 | 2020-02-20 |
卷号 | 634页码:10 |
ISSN号 | 0004-6361 |
关键词 | binaries: general stars: neutron subdwarfs stars: formation |
DOI | 10.1051/0004-6361/201935792 |
产权排序 | 第1完成单位 |
文献子类 | Article |
英文摘要 | Context. Subdwarf B stars (sdBs) play a crucial role in stellar evolution, asteroseismology, and far-UV radiation of early-type galaxies, and have been intensively studied with observation and theory. It has theoretically been predicted that sdBs with neutron star (NS) companions exist in the Galaxy, but none have been discovered yet. This remains a puzzle in this field. In a previous study (hereafter Paper I), we have studied the formation channels of sdB+NS binaries from main-sequence (MS) stars plus NS binaries by establishing a model grid, but it is still unclear how these binaries consisting of MS stars and NS binaries came to be in the first place.Aims. We systematically study the formation of sdB+NS binaries from their original zero-age main-sequence progenitors. We bridge the gap left by our previous study in this way. We obtain the statistical population properties of sdB+NS binaries and provide some guidance for observational efforts.Methods. We first used Hurley's rapid binary evolution code BSE to evolve 10(7) primordial binaries to the point where the companions of NS+MS, NS+Hertzsprung gap star, and NS+Giant Branch star binaries have just filled their Roche lobes. Next, we injected these binaries into the model grid we developed in Paper I to obtain the properties of the sdB+NS populations. We adopted two prescriptions of NS natal kicks: the classical Maxwellian distribution with a dispersion of sigma=265 km s(-1), and a linear formula that assumes that the kick velocity is associated with the ratio of ejected to remnant mass. Different values of alpha(CE), where alpha(CE) is the common-envelope ejection efficiency, were chosen to examine the effect of common-envelope evolution on the results.Results. In the Galaxy, the birthrate of sdB+NS binaries is about 10(-4) yr(-1) and there are similar to 7000-21 000 such binaries. This contributes 0.3-0.5% of all sdB binaries in the most favorable case. Most Galactic sdB+NS binaries (greater than or similar to 60%) arise from the channel of stable mass transfer. The value of alpha(CE) has little effect on the results, but when we use the linear formula prescription of NS natal kick, the number and birthrate doubles in comparison to the results we obtained with the Maxwellian distribution. The orbital periods of sdB+NS binaries from different formation channels differ significantly, as expected. This results in two peaks in the radial velocity (RV) semi-amplitude distribution: 100-150 km s(-1) for stable mass transfer, and 400-600 km s(-1) for common-envelope ejection. However, the two sdB+NS binary populations exhibit similar delay-time distributions, which both peak at about 0.2 Gyr. This indicates that Galactic sdB+NS binaries are born in very young populations, probably in the Galactic disk. The sdB+NS binaries produced from the common-envelope ejection channel are potential sources of strong gravitational wave radiation (GWR), and about similar to 100-300 could be detected by the Laser Interferometer Space Antenna (LISA) with a signal-to-noise ratio of 1.Conclusions. Most sdB+NS binaries are located in the Galactic disk with small RV semi-amplitudes. SdB+NS binaries with large RV semi-amplitudes are expected to be strong GWR sources, some of which could be detected by LISA in the future. |
学科主题 | 天文学 ; 恒星与银河系 ; 恒星形成与演化 |
URL标识 | 查看原文 |
出版地 | 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE |
WOS关键词 | ELECTRON-CAPTURE SUPERNOVAE ; WHITE-DWARFS ; MASS ; EVOLUTION ; PROGENITORS ; COLLAPSE ; CHANNEL ; ORIGIN ; MODEL ; BIRTHRATE |
资助项目 | Natural Science Foundation of China[11733008] ; Natural Science Foundation of China[11521303] ; Natural Science Foundation of China[11703081] ; National Ten-thousand talents program, CAS light of West China Program ; Youth Innovation Promotion Association of the CAS[2018076] |
WOS研究方向 | Astronomy & Astrophysics |
语种 | 英语 |
出版者 | EDP SCIENCES S A |
WOS记录号 | WOS:000515681100001 |
资助机构 | Natural Science Foundation of China[11733008, 11521303, 11703081] ; National Ten-thousand talents program, CAS light of West China Program ; Youth Innovation Promotion Association of the CAS[2018076] |
源URL | [http://ir.ynao.ac.cn/handle/114a53/22548] |
专题 | 云南天文台_大样本恒星演化研究组 云南天文台_中国科学院天体结构与演化重点实验室 |
通讯作者 | Wu Y(吴优) |
作者单位 | 1.Yunnan Observatories, Chinese Academy of Sciences, Kunming 650216, PR China 2.Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650216, PR China 3.University of the Chinese Academy of Science, Beijing 100049, PR China 4.Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012, PR China |
推荐引用方式 GB/T 7714 | Wu Y,Chen XF,Chen HL,et al. Hot subdwarf B stars with neutron star components: II. Binary population synthesis[J]. ASTRONOMY & ASTROPHYSICS,2020,634:10. |
APA | Wu Y,Chen XF,Chen HL,Li ZW,&Han ZW.(2020).Hot subdwarf B stars with neutron star components: II. Binary population synthesis.ASTRONOMY & ASTROPHYSICS,634,10. |
MLA | Wu Y,et al."Hot subdwarf B stars with neutron star components: II. Binary population synthesis".ASTRONOMY & ASTROPHYSICS 634(2020):10. |
入库方式: OAI收割
来源:云南天文台
其他版本
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。