인문학
사회과학
자연과학
공학
의약학
농수해양학
예술체육학
복합학
지원사업
학술연구/단체지원/교육 등 연구자 활동을 지속하도록 DBpia가 지원하고 있어요.
커뮤니티
연구자들이 자신의 연구와 전문성을 널리 알리고, 새로운 협력의 기회를 만들 수 있는 네트워킹 공간이에요.
초록·키워드
Context. In addition to being spectacular objects, very massive stars (VMSs) are suspected to have a tremendous impact on their environment and on cosmic evolution in general. The nucleosynthesis both during their advanced stages and their final explosion may contribute greatly to the overall enrichment of the Universe. Their resulting supernovae are candidates for the most superluminous events possible and their extreme conditions also lead to very important radiative and mechanical feedback effects, from local to cosmic scale. Aims. We explore the impact of rotation and metallicity on the evolution of VMSs over cosmic time. Methods. With the recent implementation of an equation of state in the GENEC stellar evolution code, which is appropriate for describing the conditions in the central regions of very massive stars in their advanced phases, we present new results on VMS evolution from Population III to solar metallicity. Results. Low-metallicity VMS models are highly sensitive to rotation, while the evolution of higher-metallicity models is dominated by mass-loss effects. The mass loss strongly affects their surface velocity evolution, breaking quickly at high metallicity while reaching the critical velocity for low-metallicity models. Comparison to observed VMSs in the LMC shows that the mass-loss prescriptions used for these models are compatible with observed mass-loss rates. In our framework for modeling rotation, our models of VMS need a high initial velocity in order to reproduce the observed surface velocities. The surface enrichment of these VMSs is difficult to explain with only one initial composition, and could suggest multiple populations in the R136 cluster. At a metallicity typical of R136, only our non- or slowly rotating VMS models may produce pair-instability supernovae. The most massive black holes that can be formed are less massive than about 60 M ⊙ . Conclusions. Direct observational constraints on VMS are still scarce. Future observational campaigns will hopefully gather more pieces of information to guide the theoretical modeling of these objects, whose impacts can be very important. VMS tables are available at the CDS.
인공지능 문자 인식 모델을 통해 추출된 텍스트로, 일부 오타나 오류가 포함될 수 있으나 지속적으로 개선 중입니다.
오류를 발견하셨다면 해당 부분을 드래그한 후 ' 를 통해 신고해주세요.
오류를 발견하셨다면 해당 부분을 드래그한 후 ' 를 통해 신고해주세요.