论文标题
浮士德vi。 VLA 1623--2417 B：50 au量表的Protostars周围的天体化学实验室
FAUST VI. VLA 1623--2417 B: a new laboratory for astrochemistry around protostars on 50 au scale
论文作者
论文摘要
ALMA干涉仪具有高敏性和高角度分辨率的前所未有的组合，可以在太阳系尺度上（亚）MM波长映射（亚）MM波长映射。在这些喷射磁盘系统中，天体化学受益于成像星际复合有机分子。在这里，我们报告了第一次检测甲醇（CH3OH）和甲基甲酸甲酯（HCOOCH3）对三重Protostellar系统VLA1623-2417 A1+A2+B的发射，该系统在Alma大型程序Faust的背景下获得。在EU = 45 K至61 K和537 K的线中，将紧凑的甲醇发射分别检测到成分A1和B。 LVG对CH3OH线对VLA1623-2417 B的分析表明，大小为0.11-0.34 ARCSEC（14-45 au），柱密度N（CH3OH）= 10^16-10^17 cm-2，动力学温度> 170 K，体积密度> 10^8 cm-3。考虑到有限的EU范围，使用LTE方法用于VLA123-2417 A1，并且产生<135 K的小动物。VLA1623-2417A1和B周围的甲醇发射和B均显示出沿每个磁盘主轴的速度梯度。尽管两个磁盘的轴向几何形状相似，但观察到的速度梯度却相反。 B的CH3OH光谱显示出两个宽（4-5 km S-1）峰，它们的红色和蓝色偏移约为6-7 km S-1，与全身速度相距约6-7 km。假设在吸积盘中具有化学富集的环，接近离心屏障，则将其半径计算为33 au。朝向A1的甲醇光谱较窄（大约4 km S-1），这意味着半径为12-24 au。
The ALMA interferometer, with its unprecedented combination of high-sensitivity and high-angular resolution, allows for (sub-)mm wavelength mapping of protostellar systems at Solar System scales. Astrochemistry has benefited from imaging interstellar complex organic molecules in these jet-disk systems. Here we report the first detection of methanol (CH3OH) and methyl formate (HCOOCH3) emission towards the triple protostellar system VLA1623-2417 A1+A2+B, obtained in the context of the ALMA Large Program FAUST. Compact methanol emission is detected in lines from Eu = 45 K up to 61 K and 537 K towards components A1 and B, respectively. LVG analysis of the CH3OH lines towards VLA1623-2417 B indicates a size of 0.11-0.34 arcsec (14-45 au), a column density N(CH3OH) = 10^16-10^17 cm-2, kinetic temperature > 170 K, and volume density > 10^8 cm-3. An LTE approach is used for VLA1623-2417 A1, given the limited Eu range, and yields Trot < 135 K. The methanol emission around both VLA1623-2417 A1 and B shows velocity gradients along the main axis of each disk. Although the axial geometry of the two disks is similar, the observed velocity gradients are reversed. The CH3OH spectra from B shows two broad (4-5 km s-1) peaks, which are red- and blue-shifted by about 6-7 km s-1 from the systemic velocity. Assuming a chemically enriched ring within the accretion disk, close to the centrifugal barrier, its radius is calculated to be 33 au. The methanol spectra towards A1 are somewhat narrower (about 4 km s-1), implying a radius of 12-24 au.
