论文标题
NGC7538 IRS1-驾驶电离喷气机和巨型N-S流出的O星
NGC7538 IRS1 -- an O star driving an ionized jet and giant N-S outflow
论文作者
论文摘要
NGC 7538 IRS 1是一颗非常年轻的O恒星，驾驶离子喷射和积聚质量> 10^-4 msun/年，它正在淬灭超紧张的HII区域。我们使用SOFIA出色的数据，Herschel PAC和Spire存档数据，Sofia Forcast档案数据，Onsala 20M和Carma数据以及JCMT档案数据来确定O Star及其流出的属性。 IRS 1似乎是单个O-Star，具有降压光度> 1 10^5 LSUN，即O7频谱型O7。我们发现，IRS 1驱动大型分子流出，蓝色移位的北流叶延伸至〜280英寸或3.6 pc，距IRS1。近IRS 1近1近IRS 1与离子喷气机很好地对齐。流出的动力学时间尺度为〜1.3 10^5 Yr。总流出量〜130 msun/ys ys ys ys ys ys y ys y ys y y ys y y y y y ys 1.0^ground。观察到的质量吸收率费率下降，HII区域将迅速开始扩展。
NGC 7538 IRS 1 is a very young embedded O star driving an ionized jet and accreting mass with an accretion rate > 10^-4 Msun/year, which is quenching the hypercompact HII region. We use SOFIA GREAT data, Herschel PACS and SPIRE archive data, SOFIA FORCAST archive data, Onsala 20m and CARMA data, and JCMT archive data to determine the properties of the O star and its outflow. IRS 1 appears to be a single O-star with a bolometric luminosity > 1 10^5 Lsun, i.e. spectral type O7 or earlier. We find that IRS 1 drives a large molecular outflow with the blue-shifted northern outflow lobe extending to ~ 280" or 3.6 pc from IRS 1. Near IRS 1 the outflow is well aligned with the ionized jet. The dynamical time scale of the outflow is ~ 1.3 10^5 yr. The total outflow mass is ~ 130 Msun. We determine a mass outflow rate of 1.0 10^-3 Msun/yr, roughly consistent with the observed mass accretion rate. We observe strong high velocity [CII] emission in the outflow, confirming that strong UV radiation from IRS 1 escapes into the outflow lobes and is ionizing the gas. Many O stars may form like low mass stars, but with a higher accretion rate and in a denser environment. As long as the accretion stays high enough to quench the HII region, the star will continue to grow. When the accretion rate drops, the HII region will rapidly start to expand.
