通过高分辨率光学光谱探测V1180 Cas中的吸积与外流
Probing Accretion and Outflow in V1180 Cas through High-Resolution Optical Spectroscopy
- Aryabhatta Research Institute of Observational Sciences (ARIES)（阿里亚巴塔观测科学研究所）
- M.J.P. Rohilkhand University（M.J.P.罗希尔坎德大学）
- Department of Astronomy and Astrophysics Tata Institute of Fundamental Research (TIFR)（塔塔基础研究院天文与天体物理系）
- Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México（墨西哥国立自治大学射电天文学与天体物理研究所）
- Indian Institute of Technology (IIT) Roorkee（印度理工学院勒克瑙分校）
- Bareilly College（巴雷利学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
通过Keck HIRES高分辨率光谱分析V1180 Cas，首次测定其视向速度与盘倾角，揭示吸积与外流特征，支持多成分外流模型。
AI中文摘要：
我们展示了在W. M. Keck天文台使用HIRES获取的V1180 Cas高分辨率光学光谱的分析结果，该光谱是在源处于明亮光度状态时获得的。光谱以强发射线为主，包括H$\alpha$、Ca II红外三重线、He I和O I，以及众多Fe I和Fe II跃迁线和若干禁线如[O I]和[S II]，表明正在进行的吸积和质量损失活动。微弱的Li I $\lambda$6708吸收特征证实了该源的年轻性。利用Li I吸收线和选定的Fe I发射线，我们首次报告了V1180 Cas的视向速度为$-16 \pm 3$ km s$^{-1}$。H$\alpha$和H$\beta$轮廓呈现出不对称结构，带有蓝移吸收成分，表明沿视线方向存在外流物质。He I $\lambda$5876线显示出窄成分，可能与激波后吸积区域相关，以及一个宽的、略微蓝移的成分，可能来自磁层流和/或内盘风。[O I] $\lambda$6300轮廓被分解为低速和高速成分，分别追踪慢盘风和快喷流。利用禁线[O I]，我们首次估计了盘倾角约为$50^\circ$。推导出的质量吸积率和喷流质量损失率表明$\dot{M}_{jet}/\dot{M}_{acc} \sim 0.01$--$0.03$，处于Class II YSOs观测范围的下端，但与其一致。禁线诊断表明密度约为$10^{3}$和$10^{6}$ cm$^{-3}$，温度约为$10^{4}$ K，支持多成分外流情景。总体而言，结果支持V1180 Cas是一个活跃吸积、中等倾角系统，拥有多成分外流的图像。
英文摘要：
We present an analysis of a high-resolution optical spectrum of V1180 Cas obtained with HIRES at the W. M. Keck Observatory during a bright photometric state of the source. The spectrum is dominated by strong emission lines, including H$α$, the Ca II infrared triplet, He I, and O I, along with numerous Fe I and Fe II transitions and several forbidden lines such as [O I] and [S II], indicating ongoing accretion and mass-loss activity. A weak Li I $λ$6708 absorption feature confirms the youth of the source. Using the Li I absorption and selected Fe I emission lines, we report for the first time a radial velocity of $-16 \pm 3$ km s$^{-1}$ for V1180 Cas. The H$α$ and H$β$ profiles exhibit asymmetric structures with blueshifted absorption components, suggesting outflowing material along the line of sight. The He I $λ$5876 line displays a narrow component likely associated with post-shock accretion regions and a broad, slightly blueshifted component probably arising from magnetospheric flows and/or inner disk winds. The [O I] $λ$6300 profile is decomposed into low- and high-velocity components, tracing a slow disk wind and a fast jet. Using the forbidden [O I] line, we estimate for the first time a disk inclination angle of $\approx50^\circ$. The derived mass accretion and jet mass-loss rates imply $\dot{M}_{jet}/\dot{M}_{acc} \sim 0.01$--$0.03$, at the lower end of, but consistent with, the range observed for Class II YSOs. Forbidden-line diagnostics indicate densities $\sim10^{3}$ and $10^{6}$ cm$^{-3}$ with temperatures of $\sim10^{4}$ K, supporting a multi-component outflow scenario. Overall, the results support a picture in which V1180 Cas is an actively accreting, moderately inclined system hosting a multi-component outflow.
