arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0901.4492astro-ph.SR
收藏

年轻行星状星云K~3-35的磁场

The magnetic field toward the young planetary nebula K~3-35

Y. Gomez, D. Tafoya, G. Anglada, L. F. Miranda, J. M. Torrelles, N. A. Patel, R. Franco-Hernandez

备注：
6 pages, 2 tables, 4 figures, ApJ accepted
发表信息：
Astrophys.J.695:930-936,2009
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

K 3-35是一个行星状星云（PN），在那里探测到了H2O脉泽发射，这表明它在几十年前才脱离了原行星状星云阶段。本文报道了用干涉VLA方法对K~3-35中OH ~（18）cm跃迁的观测结果，在1612、1665、1667和1720 MHz四条基态谱线上都探测到OH脉泽发射。OH 1665和1720 MHz脉泽在空间上与星云核心一致，而OH 1612和1667 MHz脉泽在空间上与星云核心一致，而OH 1612和1667 MHz脉泽在空间上与星云核心一致。我们认为，1665和1720脉泽产生于一个区域靠近中央恒星，可能在一个环面，而1612和1667线主要来自扩展的北叶流出。值得注意的是，OH 1720 MHz脉泽发射的位置和速度与H2O脉泽非常相似（分别在0.1”和~2 km/s范围内一致）。我们认为，在H2O脉泽泵浦机制可以产生相同的冲击，激发OH 1720 MHz的过渡。发现1612、1665、1666、1667、1668、1669、1690、1990在~ +18 km/s的1665 MHz跃迁中，（LCP和RCP）在直径约0.03”的区域内空间上重合。假设这些RCP和LCP 1665特征来自塞曼对，我们估计在1.3 cm连续谱峰的150 AU范围内存在约0.9 mG的磁场。这个值与演化恒星的太阳型磁场一致。

英文摘要：

K 3-35 is a planetary nebula (PN) where H2O maser emission has been detected, suggesting that it departed from the proto-PNe phase only some decades ago. Interferometric VLA observations of the OH 18 cm transitions in K~3-35 are presented.OH maser emission is detected in all four ground state lines (1612, 1665, 1667, and 1720 MHz). All the masers appear blueshifted with respect to the systemic velocity of the nebula and they have different spatial and kinematic distributions.The OH 1665 and 1720 MHz masers appear spatially coincident with the core of the nebula, while the OH 1612 and 1667 MHz ones exhibit a more extended distribution. We suggest that the 1665 and 1720 masers arise from a region close to the central star, possibly in a torus, while the 1612 and 1667 lines originate mainly from the extended northern lobe of the outflow. It is worth noting that the location and velocity of the OH 1720 MHz maser emission are very similar to those of the H2O masers (coinciding within 0.1" and ~2 km/s, respectively). We suggest that the pumping mechanism in the H2O masers could be produced by the same shock that is exciting the OH 1720 MHz transition. A high degree of circular polarization (>50%) was found to be present in some features of the 1612, 1665, and 1720 MHz emission.For the 1665 MHz transition at ~ +18 km/s the emission with left and right circular polarizations (LCP and RCP) coincide spatially within a region of ~0.03" in diameter.Assuming that these RCP and LCP 1665 features come from a Zeeman pair, we estimate a magnetic field of ~0.9 mG within 150 AU from the 1.3 cm continuum peak. This value is in agreement with a solar-type magnetic field associated with evolved stars.

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。

↑