인문학
사회과학
자연과학
공학
의약학
농수해양학
예술체육학
복합학
DBpia AI
AI 에이전트
AI 아이디어
AI 리더
AI 뷰어
Citeasy
크롬 서지관리 다운로드
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
β Pictoris is a young A5V star known for harbouring a large number of cometary-like objects (or exocomets) that frequently transit the star and create variable absorption signatures in its spectrum. The physical and chemical properties of these exocomets can be probed by the recently introduced curve of growth approach, which enables column densities measurements in cometary tails using absorption measurements in numerous spectral lines. Through this approach, we present a new study of archival spectra of β Pic obtained with the Hubble Space Telescope, the HARPS spectrograph, and at the Mont John University Observatory aimed at constraining the abundance of refractory ions in β Pic exocomets. We studied 29 individual objects, all of which were observed in Fe II lines (used as a reference ion) and at least one other species (e.g. Ni II , Ca II , Cr II ). We find that the refractory composition of β Pic exocomets is stable overall, especially for singly ionised species, and consistent with solar abundances. This outcome validates the use of the curve of growth approach to study exocometary composition. We also show that some ions, such as Ca II , are significantly depleted compared to solar abundances, which allowed us to constrain the typical ionisation state in β Pic exocomets. We find that most refractory elements (e.g. Mg, Ni, Fe) are split into similar fractions between their first and second ionisation states, with the exception of Ca, which is mostly ionised twice. A strong correlation between the Al III /Fe II ratio and radial velocity is also found, showing that the most redshifted exocomets tend to be more ionised. These results open the way for further modelling of exocomets in order to unveil their composition and the physical processes that affect their tails.
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.
최근 본 자료 전체보기
