The distance to the Serpens South Cluster from H2O masers

Autor: Ortiz-Leon, Gisela N., Dzib, Sergio A., Loinard, Laurent, Gong, Yan, Pillai, Thushara, Plunkett, Adele
Rok vydání: 2023
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1051/0004-6361/202346369
Popis: 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 into account depth effects, we obtain a distance to the cluster of 440.7+/-4.6 pc. Stars visible in the optical that have astrometric solutions in the Gaia Data Release 3 are, on the other hand, all located in the periphery of the cluster. Their mean distance of 437 (+51, -41) pc is consistent within 1-sigma with the value derived from maser astrometry. As the maser source is just at the center of Serpens South, we finally solve the ambiguity of the distance to this region that has prevailed over the years.
Comment: Accepted to A&A Letters; Co-author spelling name corrected
Databáze: arXiv