First observations of the water masers with the Urumqi 25m radio telescope

A new radio spectral receiving system has been installed on the 25 rn radio telescope of the Urumqi Astronomical Observatory. The back end is a surface acoustic wave chirp transform spectrometer (SAW CZT), used for the first time in radio astronomy. The calibration of the line observations has carefully been investigated for the new-type spectrometer. In order to test the feasibility of the prototype spectrometer, we observed water maser emission from a number of known Galactic sources. We describe the observed spectra of W49N, W3(OH), 2248 + 600 and 1909 + 090. We found that W49N spectrum showed high-velocity features ranging from - 330 to 146 km s(-1). In comparison with the spectra observed by Medicina, the feature at the LSR velocity - 52 km s(-1) in the W3(OH) presented the rapid variation in flux density.