Herschel/PACS对海王星观测的初步结果
地球与行星天体物理
2015-05-19 v1
摘要
我们报告了对海王星的Herschel/PACS全范围光谱的初步分析，该光谱覆盖51-220微米范围，平均分辨本领约为3000，并辅以对CH4在120微米处的专门观测。存在大量来自HD（R(0)和R(1)）、H2O、CH4和CO的光谱特征，但迄今未发现新物种。我们的结果表明：（i）海王星的平均热廓线比从旅行者号射电掩星推断的温度高约3 K；（ii）D/H混合比为(4.5+/-1) X 10**-5，证实了海王星相对于原太阳值（约2.1 X 10**-5）的氘富集；（iii）中平流层中CH4的混合比为(1.5+/-0.2) X 10**-3，且CH4在低平流层中以与局地饱和一致的速度减少，这与CH4从海王星温暖的南极地区注入平流层的场景相符；（iv）H2O平流层柱密度为(2.1+/-0.5) X 10**14 cm-2，但其垂直分布仍有待确定，因此H2O外部通量仍存在超过一个数量级的不确定性；（v）CO平流层丰度约为对流层值的两倍，证实了从地面毫米/亚毫米观测中怀疑的CO双重起源。
引用
@article{arxiv.1006.0114,
title = {First results of Herschel/PACS observations of Neptune},
author = {E. Lellouch and P. Hartogh and H. Feuchtgruber and B. Vandenbussche and T. de Graauw and R. Moreno and C. Jarchow and T. Cavalié and G. Orton and M. Banaszkiewicz and M. I. Blecka and D. Bockelée-Morvan and J. Crovisier and T. Encrenaz and T. Fulton and M. Küppers and L. M. Lara and D. C. Lis and A. S. Medvedev and M. Rengel and H. Sagawa and B. Swinyard and S. Szutowicz and F. Bensch and E. Bergin and F. Billebaud and N. Biver and G. A. Blake and J. A. D. L. Blommaert and J. Cernicharo and R. Courtin and G. R. Davis and L. Decin and P. Encrenaz and A. Gonzalez and E. Jehin and M. Kidger and D. Naylor and G. Portyankina and R. Schieder and S. Sidher and N. Thomas and M. de Val-Borro and E. Verdugo and C. Waelkens and H. Walker and H. Aarts and C. Comito and J. H. Kawamura and A. Maestrini and T. Peacocke and R. Teipen and T. Tils and K. Wildeman},
journal= {arXiv preprint arXiv:1006.0114},
year = {2015}
}
备注
Accepted for publication in Astronomy & Astrophysics (special issue on Herschel first results)