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arXiv 1411.7823astro-ph.SR
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Cha II中[ OI ]和H2O的Herschel - PACS观测

Herschel -PACS observations of [OI] and H2O in Cha II

P. Riviere-Marichalar, A. Bayo, I. Kamp, S. Vicente, J. P. Williams, D. Barrado, C. Eiroa, G. Duchne, B. Montesinos, G. Mathews, L. Podio, W. R. F. Dent, N. Huélamo, B. Merín

摘要:

气体在原行星盘的动力学演化中起着重要的作用。它与尘埃的结合是我们理解行星形成的关键。因此,研究气体含量是了解原行星盘演化的关键一步。这种研究可以通过远红外线发射谱线的光谱观察来进行,其中一些最重要的气体冷却剂发射,例如63.18微米处的[OI] 3 P1 -3 P2跃迁。我们的目的是在描述的气体含量的原行星盘中的中间年龄Chamaeleon II(Cha II)恒星形成区域。我们的目标也是在这个年龄范围内,这是一个必不可少的步骤跟踪气体演化与年龄在不同的恒星形成区域的气体检测分数的特征。我们获得了赫歇尔PACS线扫描光谱观测在63微米的19 Cha II类I和II星。观察结果用于在63微米处追踪[OI]和o-H2O。[OI]的空间分布的分析,当扩展时,可以用来理解排放的起源。我们已经检测到[OI]发射朝向7个观察到的19个系统,和o-H2O发射在63.32微米,只有其中之一,Sz 61。Cha II成员显示了[OI]线通量和70微米连续体之间的相关性,类似于在金牛座中观察到的。我们分析了扩展的[OI]发射对恒星DK茶和PACS积分场单元(IFU)研究其动力学足迹。我们的结论是,有一个高的速度分量从射流结合低速分量的起源,可能是一个组合的磁盘,信封和风排放。在[OI]中没有单独检测到的物体的光谱的叠加导致边缘2.6西格玛检测,这可能表明其中一些(如果不是全部)的气体的存在略低于我们的检测限。

英文摘要:

Gas plays a major role in the dynamical evolution of protoplanetary discs. Its coupling with the dust is the key to our understanding planetary formation. Studying the gas content is therefore a crucial step towards understanding protoplanetary discs evolution. Such a study can be made through spectroscopic observations of emission lines in the far-infrared, where some of the most important gas coolants emit, such as the [OI] 3P1-3 P2 transition at 63.18 microns. We aim at characterising the gas content of protoplanetary discs in the intermediate-aged Chamaeleon II (Cha II) star forming region. We also aim at characterising the gaseous detection fractions within this age range, which is an essential step tracing gas evolution with age in different star forming regions. We obtained Herschel-PACS line scan spectroscopic observations at 63 microns of 19 Cha II Class I and II stars. The observations were used to trace [OI] and o-H2O at 63 microns. The analysis of the spatial distribution of [OI], when extended, can be used to understand the origin of the emission. We have detected [OI] emission toward seven out of the nineteen systems observed, and o-H2O emission at 63.32 microns in just one of them, Sz 61. Cha II members show a correlation between [OI] line fluxes and the continuum at 70 microns, similar to what is observed in Taurus. We analyse the extended [OI] emission towards the star DK Cha and study its dynamical footprints in the PACS Integral Field Unit (IFU). We conclude that there is a high velocity component from a jet combined with a low velocity component with an origin that may be a combination of disc, envelope and wind emission. The stacking of spectra of objects not detected individually in [OI] leads to a marginal 2.6sigma detection that may indicate the presence of gas just below our detection limits for some, if not all, of them.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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