The researchers in the SHAO and the PMO have observed a sample of 288 molecular outflow sources to search for class I methanol masers at 95.1GHz with the PMO 13.7m radio telescope. Our survey detected 68 class I methanol masers, which include 19 newly detected class I methanol masers (13 high-mass and 6 low-mass sources). The importance is that the detection of the newly 6 low-mass sources increase the sample numbers of the low-mass class I methanol masers. Statistical analysis for the distributions of maser detections with outflow parameters reveals that the maser detection efficiency increases with outflow properties. Systematic investigations of relationships between the intrinsic luminosity of methanol maser and the outflow properties (including mass, momentum, kinetic energy, bolometric luminosity and mass loss rate of central stellar sources) indicate a positive correlations. The paper will be presented at ApJ (http://arxiv.org/abs/1211.2411).

Figure 1: The log–log distributions between class I methanol maser luminosity and outflow properties including bolometric luminosity of central sources (a), outflow mass (b), momen- tum of outflows (c), and kinetic energy of outflows (d). The green squares and red triangles represent high-mass and low-mass sources, respetively. The solid black line is the best linear fit of the plot .