Galactic locations of the 417 O-rich AGB stars from Mauron et al. (2019). The three blue lines indicate the B = 0° ± 10° plane, where B is the latitude of Sgr stream coordinate system. The red circles denote the 50 sources observed with the Tianma 65 m telescope and the blue circles denote the 52 sources observed with the Effelsberg 100 m telescope. The yellow circles denote the eight sources with the detection of SiO masers. The open circles represent the stars which are not included in the current pilot survey.