大质量恒星形成区中的水：W3 IRS5的HIFI观测
太阳与恒星天体物理
2015-05-19 v2
摘要
我们展示了赫歇尔空间天文台对大质量恒星形成区W3 IRS5中水分子的观测结果。利用HIFI高光谱分辨率探测到了o-H17O 110-101、p-H18O 111-000、p-H2O 22 202-111、p-H2O 111-000、o-H2O 221-212和o-H2O 212-101谱线，覆盖频率范围从552 GHz到1669 GHz。W3 IRS5中的水谱线显示出清晰的高速翼，表明存在明显的星风贡献。此外，H2O谱线中系统性的蓝移吸收暗示了膨胀，这很可能是由星风驱动的。未探测到内落信号。p-H2O 111-000和o-H2O 212-101谱线显示出高质原恒星包层所嵌入的冷物质（T ~ 10 K）的吸收。我们使用一维辐射传输模型来估计水丰度并进一步研究该区域的运动学。我们表明，稀有同位素体的发射直接来自包层内部（T > 100 K），在那里尘埃包层中的水冰蒸发，气相丰度增加。在我们的模型中，需要由此产生的水丰度跳跃（内部恒定丰度为10^{-4}）来重现o-H17O 110-101和p-H18O 111-000谱线。我们估计包层外部（T < 100 K）的水丰度为10^{-8}至10^{-9}。讨论了可能有两个原恒星天体对发射有贡献的可能性。
引用
@article{arxiv.1007.3986,
title = {Water in massive star-forming regions: HIFI observations of W3 IRS5},
author = {L. Chavarria and F. Herpin and T. Jacq and J. Braine and S. Bontemps and A. Baudry and M. Marseille and F. van der Tak and B. Pietropaoli and F. Wyrowski and R. Shipman and W. Frieswijk and E. F. van Dishoeck and J. Cernicharo and R. Bachiller and M. Benedettini and A. O. Benz and E. Bergin and P. Bjerkeli and G. A. Blake and S. Bruderer and P. Caselli and C. Codella and F. Daniel and A. M. di Giorgio and C. Dominik and S. D. Doty and P. Encrenaz and M. Fich and A. Fuente and T. Giannini and J. R. Goicoechea and Th. de Graauw and P. Hartogh and F. Helmich and G. J. Herczeg and M. R. Hogerheijde and D. Johnstone and J. K. Jørgensen and L. E. Kristensen and B. Larsson and D. Lis and R. Liseau and C. McCoey and G. Melnick and B. Nisini and M. Olberg and B. Parise and J. C. Pearson and R. Plume and C. Risacher and J. Santiago-Garcia and P. Saraceno and J. Stutzki R. Szczerba and M. Tafalla and A. Tielens and T. A. van Kempen and R. Visser and S. F. Wampfler and J. Willem and U. A. Yıldız},
journal= {arXiv preprint arXiv:1007.3986},
year = {2015}
}
备注
Accepted for publication in the A&A HIFI special issue