论文标题

通过深度高光谱分辨率光谱iii:HH514

Photoionized Herbig-Haro objects in the Orion Nebula through deep high-spectral resolution spectroscopy III: HH514

论文作者

Méndez-Delgado, J. E., Esteban, C., García-Rojas, J., Henney, W. J., .

论文摘要

我们分析了光电离Herbig-Haro物体HH〜514的物理条件和化学组成,该物体从猎户座星云的核心中的170-337出现。我们在Gran Telescopio de Canarias的Megara非常大的望远镜和IFU-Spectra的高光谱分辨率光谱中使用。我们观察两个组件的HH〜514组件,即喷射底座和一个结,带有$ n _ {\ rm e} =(2.3 \ pm 0.1)\ times 10^5 \ text {cm}^{ - 3} $ and $ n _ {\ rm e} =(\ rm e} =(7 \ rm e} =(7 \ pm 1)分别使用$ t _ {\ rm e} \大约9000 \ text {k} $。我们表明,HH〜514的化学组成与猎户座星云的化学组成是一致的,除了fe,ni和s外,它显示出较高的丰度。与一般的星际介质相比,在HH物体中观察到的Fe和Ni的丰度增强通常被解释为粉尘晶粒的破坏。观察到的硫过度(超过两次太阳能)是具有挑战性的,因为来自同一磁盘的推定光蒸发流动表现出正常的硫丰度。如果上述的S弥散性是由于粉尘破坏引起的,则可以将硫化物和/或其他含粉尘储层的形成与Protoplanetary磁盘中的行星形成过程有关,这些磁盘会过滤大量的硫化物粉尘粒,从物质从磁盘上降低到中心恒星。我们还表明,靠近中心恒星的分子发射的运动学与垂直于光学射流的磁盘不一致,也与与之对齐的流出相一致。

We analyze the physical conditions and chemical composition of the photoionized Herbig-Haro object HH~514, which emerges from the proplyd 170-337 in the core of the Orion Nebula. We use high-spectral resolution spectroscopy from UVES at the Very Large Telescope and IFU-spectra from MEGARA at the Gran Telescopio de Canarias. We observe two components of HH~514, the jet base and a knot, with $n_{\rm e}= (2.3 \pm 0.1) \times 10^5 \text{cm}^{-3}$ and $n_{\rm e}= (7 \pm 1) \times 10^4 \text{cm}^{-3}$, respectively, both with $T_{\rm e}\approx 9000 \text{ K}$. We show that the chemical composition of HH~514 is consistent with that of the Orion Nebula, except for Fe, Ni and S, which show higher abundances. The enhanced abundances of Fe and Ni observed in HH objects compared with the general interstellar medium is usually interpreted as destruction of dust grains. The observed sulphur overabundance (more than two times solar) is challenging to explain since the proplyd photoevaporation flow from the same disk shows normal sulphur abundance. If the aforementioned S-overabundance is due to dust destruction, the formation of sulfides and/or other S-bearing dust reservoirs may be linked to planet formation processes in protoplanetary disks, which filter large sulfide dust grains during the accretion of matter from the disk to the central star. We also show that published kinematics of molecular emission close to the central star are not consistent with either a disk perpendicular to the optical jet, nor with an outflow that is aligned with it.

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