[CII] 158 micron line detection of the warm ionized medium in the Scutum--Crux spiral arm tangency
[CII] 158 micron line detection of the warm ionized medium in the Scutum--Crux spiral arm tangency
复制标题
[CII]盾板中温电离介质的158微米线检测--Crux旋臂相切
DOI：
10.1051/0004-6361/201219303
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
P. Goldsmith
中科院分区：
文献类型：
--
作者：
T. Velusamy;W. Langer;J. Pineda;P. Goldsmith
高保真GET C+银河平面[CII]光谱测量在旋臂切线处探测到强烈发射。我们利用Scutom-Crux(S-C)切线在I=30°附近的独特观测几何来探测[CII]追踪的热电离介质(WIM)分量，并研究螺旋密度波对星际介质气体的影响。我们将[CII]的速度特征与各经度切线速度附近的HI、12CO和13CO数据进行比较，以分离S-C切线上的冷中性介质和暖中性+电离分量，然后我们确定在没有12Co云贡献的情况下，速度最高的[CII]发射为WIM。我们给出了S-C切线的C+结果。我们将切线速度以上的扩散和扩展的超额[CII]发射解释为在WIM中以电子为主的温电离气体产生的。我们在每个经度上得到了0.2-0.9 cm^-3的电子密度，比Halpha和脉冲星色散的平均值高出好几倍。我们将S-C切线上的超额[CII]解释为螺旋密度波对WIM的激波压缩。
HIFI GOT C+ Galactic plane [CII] spectral survey has detected strong emission at the spiral arm tangencies. We use the unique viewing geometry of the Scutum-Crux (S-C) tangency near i = 30degs to detect the warm ionized medium (WIM) component traced by [CII] and to study the effects of spiral density waves on Interstellar Medium (ISM) gas. We compare [CII] velocity features with ancillary HI, 12CO and 13CO data near tangent velocities at each longitude to separate the cold neutral medium and the warm neutral + ionized components in the S-C tangency, then we identify [CII] emission at the highest velocities without any contribution from 12CO clouds, as WIM. We present the GOT C+ results for the S-C tangency. We interpret the diffuse and extended excess [CII] emission at and above the tangent velocities as arising in the electron-dominated warm ionized gas in the WIM. We derive an electron density in the range of 0.2 - 0.9 cm^-3 at each longitude, a factor of several higher than the average value from Halpha and pulsar dispersion. We interpret the excess [CII] in S-C tangency as shock compression of the WIM induced by the spiral density waves.