Multi-epoch water maser survey towards low-mass YSOs

Abstract

We present the results from a series of multi-epoch 22 GHz H2O maser surveys with the Nobeyama 45 m telescope and the VLA towards low-mass young stellar objects, including all the class 0 sources in the northern sky. Our Nobeyama 45 m survey is the deepest survey - down to an isotopic H2O luminosity of ∼ 10−13L⊙ - performed so far. From this survey, we obtained the following results. (1) Class 0 sources show high H2O maser activity: our derived detection rates are ∼ 38% for class 0, but only ∼ 4% for class I sources. (2) Activity of the H2O masers is more likely related to 100 AU scale ionized jets than to large scale molecular outflows.