论文标题
第一个静液压核心候选Chamaeleon-MMS1的流出和化学环境的高分辨率研究
High resolution study of outflows and chemical environment of First Hydrostatic Core candidate Chamaeleon-MMS1
论文作者
论文摘要
低质量恒星形成的最早阶段尚不清楚,但已提出Chamaeleon-MMS1是候选的第一静水压核(FHSC),这是Prestellar和Protostellar Core之间的过渡阶段。这项工作描述了与Chamaeleon-MMS1相关的局部(〜4000 AU)流出活动及其对周围材料的影响,以确定这种年轻的低质量来源的进化状态。我们使用Atacama大毫米/亚毫米阵列(ALMA)在高空间(〜75 au)和光谱分辨率(0.1-0.3 km/s)处观察220 GHz的Chamaeleon MMS1。通过与周围云的相互作用检测到低能流出。流出由两个组成部分组成,东北和东北地区的狭窄特征是一个宽阔的特征。将甲醛(H2CO)的旋转温度计算为50(+/- 30)k,朝着连续源的旋转温度,其温度类似低温(25-45 K)朝向受流出影响的团块。仅检测到甲醇(CH3OH)朝着远离连续源的气体团块检测到,预计甲醇有望通过冲击波中的冰溅射释放出流出的能量。 Chamaeleon-MMS1显示流出活动,电源是单个进攻流出或二进制系统的两个外流。尽管分子发射和高流出速度将其排除在FHSC中,但流出的能量不如从其他0类物体检测到的流出,而推断的气温向连续源源相对较低,这表明CHA-MMS1是最年轻的已知来源之一。
The earliest stages of low-mass star-formation are unclear, but it has been proposed that Chamaeleon-MMS1 is a candidate First Hydrostatic Core (FHSC), the transition stage between a prestellar and protostellar core. This work describes the local (~4000 AU) outflow activity associated with Chamaeleon-MMS1 and its effect on the surrounding material in order to determine the evolutionary state of this young low-mass source. We used the Atacama Large Millimeter/sub-millimeter Array (ALMA) to observe Chamaeleon MMS1 at 220 GHz at high spatial (~75 AU) and spectral resolutions (0.1-0.3 km/s). A low energy outflow is detected through its interaction with the surrounding cloud. The outflow consists of two components, a broad spectral feature to the northeast and narrow features to both the northeast and southwest. The rotational temperature of formaldehyde (H2CO) is calculated to be 50 (+/-30) K toward the continuum source with similarly low temperatures (25-45 K) toward clumps affected by the outflow. Methanol (CH3OH) is only detected toward gas clumps located away from the continuum source, where the methanol is expected to have been released by the energy of the outflow through ice sputtering in shock waves. Chamaeleon-MMS1 shows outflow activity with the power source being either a single precessing outflow or two outflows from a binary system. While molecular emission and high outflow speeds rule it out as a FHSC, the outflow is less energetic than outflows detected from other Class 0 objects and the inferred gas temperatures toward the continuum source are relatively low, which indicates that Cha-MMS1 is one of the youngest known sources.