arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1111.1474astro-ph.SR
收藏

多壳行星状星云NGC 6369的光学和红外成像及光谱

Optical and Infrared Imaging and Spectroscopy of the Multiple-Shell Planetary Nebula NGC 6369

Gerardo Ramos-Larios, Martin A. Guerrero, Roberto Vazquez, J. P. Phillips

备注：
14 pages, 13 figures. Accepted for publication in MNRAS
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

NGC 6369是一个双壳层行星状星云（PN），由明亮的环形内壳层和暗淡的双极扩展层组成。我们已经使用地面和空间的窄带光学和近红外图像，宽带中红外图像，光学长缝阶梯光谱，和中红外光谱来研究它的物理结构。这些观测结果表明，NGC 6369的内壳可以被描述为一个类似于桶的结构形状与极性泡状突起，并揭示了H2和强多环芳烃（PAHs）的光离解区（PDR）的证据位于明亮的内壳外的分子夹杂物。高分辨率的哈勃望远镜窄带图像揭示了一个复杂的激发结构的内壳和一个系统的“彗星”结。NGC 6369的包层看起来很棘手，缺乏壳层膨胀的运动学证据，PDR外电离物质的发射明显存在，这些都使我们认为NGC 6369的包层不是一个真正的壳层，而是赤道区域的一个扁平结构。我们报告了在低激发和分子线发射中发现的不规则的结和斑点的扩散发射，这些发射位于距离中心恒星80”的地方，在主星云壳层之外。我们还表明，与极性突起相关联的细丝具有与冲击后冷却制度相一致的空间范围，并且可能代表这些结构与周围材料相互作用的区域。

英文摘要：

NGC 6369 is a double-shell planetary nebula (PN) consisting of a bright annular inner shell with faint bipolar extensions and a filamentary envelope. We have used ground- and space-based narrow-band optical and near-IR images, broad-band mid-IR images, optical long-slit echelle spectra, and mid-IR spectra to investigate its physical structure. These observations indicate that the inner shell of NGC 6369 can be described as a barrel-like structure shape with polar bubble-like protrusions, and reveal evidence for H2 and strong polycyclic aromatic hydrocarbons (PAHs) emission from a photo-dissociative region (PDR) with molecular inclusions located outside the bright inner shell. High-resolution HST narrow-band images reveal an intricate excitation structure of the inner shell and a system of "cometary" knots. The knotty appearance of the envelope, the lack of kinematical evidence for shell expansion and the apparent presence of emission from ionized material outside the PDR makes us suggest that the envelope of NGC 6369 is not a real shell, but a flattened structure at its equatorial regions. We report the discovery of irregular knots and blobs of diffuse emission in low-excitation and molecular line emission that are located up to 80" from the central star, well outside the main nebular shells. We also show that the filaments associated to the polar protrusions have spatial extents consistent with post-shock cooling regimes, and likely represent regions of interaction of these structures with surrounding material.

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。

↑