The distance to the Serpens South cluster from H 2 O masers
The distance to the Serpens South cluster from H 2 O masers
复制标题
H 2 O脉泽到巨蛇南星团的距离
DOI：
10.1051/0004-6361/202346369
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发表时间：
2023
影响因子：
6.5
通讯作者：
Plunkett, Adele
中科院分区：
文献类型：
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作者：
Ortiz-León, Gisela N.;Dzib, Sergio A.;Loinard, Laurent;Gong, Yan;Pillai, Thushara;Plunkett, Adele
在这封信中，我们报告了对位于巨蛇南年轻星团中心的原恒星 CARMA-6 的 22 GHz 水微波激射器的甚长基线阵列观测。根据对微波激射点的天体测量拟合，我们得出原恒星的距离为 440.7±3.5 pc（1% 误差）。这代表了迄今为止对于如此年轻且深深嵌入这个高度模糊区域的物体所获得的最佳直接距离确定。考虑到深度效应，我们得到到星团的距离为 440.7 ± 4.6 pc。另一方面，在盖亚数据版本 3 中具有天体测量解决方案的光学中可见的恒星都位于星团的外围。它们的pc平均距离与微波天体测量得到的值一致在1σ以内。由于微波激射源位于巨蛇座南区的中心，我们终于解决了多年来一直存在的对该区域距离的模糊性。
In this Letter we report Very Long Baseline Array observations of 22 GHz water masers toward the protostar CARMA–6, located at the center of the Serpens South young cluster. From the astrometric fits to maser spots, we derive a distance of 440.7±3.5 pc for the protostar (1% error). This represents the best direct distance determination obtained so far for an object this young and deeply embedded in this highly obscured region. Taking depth effects into account, we obtain a distance to the cluster of 440.7 ± 4.6 pc. Stars visible in the optical that have astrometric solutions in theGaiaData Release 3 are, on the other hand, all located at the periphery of the cluster. Their mean distance of pc is consistent within 1σwith the value derived from maser astrometry. As the maser source is at the center of Serpens South, we finally solve the ambiguity of the distance to this region that has prevailed over the years.