arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1004.2627astro-ph.GA
收藏

首次星际探测到OH +

First interstellar detection of OH+

F. Wyrowski, K. M. Menten, R. Guesten, A. Belloche

摘要:

利用阿塔卡马探路者实验(APEX)12 m望远镜和CHAMP+外差阵列接收机,观测了909.1588 GHz处OH+的N = 1 - 0,J = 0 - 1基态跃迁。两个混合的超精细结构跃迁被检测到吸收对强连续源人马座B2(M)和在几个像素偏移18 "。在-116~38.5 km/s的速度范围内,观测到了来自银河系中心气体的吸收以及来自居间旋臂中弥漫云的吸收。吸收气体的总OH+柱密度为2.4 \times 10^15 cm-2。在Sgr B2(M)附近发现了2.6 \times 10^14 cm-2的柱密度,在中间视线上,每单位速度层的柱密度在1~40 \times 10^12 cm-2/(km/s)之间。OH+被发现平均比其他离子如SH+和CH+更丰富。OH和原子氧与OH+的绝对比值分别为10^1 - 2和10^3 - 4。检测到的吸收的连续速度范围内的视线显示OH+是一个丰富的组成部分弥漫云。

英文摘要:

The Atacama Pathfinder Experiment (APEX) 12m telescope was used to observe the N=1-0, J=0-1 ground state transitions of OH+ at 909.1588 GHz with the CHAMP+ heterodyne array receiver. Two blended hyperfine structure transitions were detected in absorption against the strong continuum source Sagittarius B2(M) and in several pixels offset by 18". Both, absorption from Galactic center gas as well as absorption from diffuse clouds in intervening spiral arms in a velocity range from -116 to 38.5 km/s is observed. The total OH+ column density of absorbing gas is 2.4 \times 10^15 cm-2. A column density local to Sgr B2(M) of 2.6 \times 10^14 cm-2 is found. On the intervening line-of-sight the column density per unit velocity interval are in the range from 1 to 40 \times 10^12 cm-2/(km/s). OH+ is found to be on average more abundant than other hydrides such as SH+ and CH+. Abundance ratios of OH and atomic oxygen to OH+ are found to be in the range of 10^1-2 and 10^3-4, respectively. The detected absorption of a continuous velocity range on the line-of-sight shows OH+ to be an abundant component of diffuse clouds.

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。

↑