Simultaneous time monitoring observations of H2O 616 − 523, SiO J = 1–0, 2–1, 3–2, and 29SiO v = 0, J = 1–0 lines are carried out in the direction of the Mira variable star TX Cam with the Korean VLBI Network single dish radio telescopes. For the first time, the H2O maser emission from TX Cam is detected near the stellar velocity at five epochs from April 10, 2013 (Ø = 3.13) to June 4, 2014 (Ø = 3.89) including minimum optical phases. The intensities of H2O masers are very weak compared to SiO masers. The variation of peak antenna temperature ratios among SiO v = 1, J = 1–0, J = 2–1, and J = 3–2 masers is investigated according to their phases. The shift of peak velocities of H2O and SiO masers with respect to the stellar velocity is also investigated according to observed optical phases. The H2O maser emission occurs around the stellar velocity during our monitoring interval. On the other hand, the peak velocities of SiO masers show a spread compared to the stellar velocity. The peak velocities of SiO J = 2–1, and J = 3–2 masers show a smaller spread with respect to the stellar velocity than those of SiO J = 1–0 masers. These simultaneous observations of multi-frequencies will provide a good constraint for maser pumping models and a good probe for investigating the stellar atmosphere and envelope according to their different excitation conditions.

A spectral line survey is performed from 159.7 to 164.7 GHz toward Orion-KL, as an extension of our previous line survey from 138.3 to 150.7 GHz with the same 14 m radio telescope of Taeduk Radio Astronomy Observatory. Typical system temperatures were 260 - 1000 K to achieve a sensitivity of about 0.02 - 0.04 K in TA unit. A total of 63 line spectra are detected in this survey. Among them, 54 lines lines are found to be the first detections towards an astronomical source and only 9 spectral lines have been previously identified from other observations. Forty-eight of 54 lines are believed to be from the known transitions of the known molecules, while 6 lines are 'unidentified'. All detected lines are found to be from a total of 10 molecular species and their isotopic variants. The molecular species with most numerous detected transitions are HCOOCH3 (22), followed by CH3OCH3 (7), C2H5CN (7), and SO2 (6). The LTE rotation diagram analysis using all homogeneous data with those from previous survey gives more reliable determination of physical quantities. The derived values of the rotation temperatures and column densities for HCOOCH3, CH3OCH3, and SO2 are are 75 ~ 197 K and 1.5 ~ 18 × 10 15 cm -2, respectively.

A molecular line survey towards the UC H II region G34.3+0.15 from 155.3 to 165.3GHz has been conducted with the TRAO 14-m radio telescope. Combined with our previous observations from 84.7 to 115.6GHz and 123.5 to 155.3GHz (Paper I), the spectral coverage of this survey in G34.3+0.15 now runs from 85 to 165 GHz. From these latest observations, a total of 18 lines from 6 species were detected. These include four new lines corresponding to ΔJ = 0, ΔK = 1 transitions of the CH3OH E-type species, and two new lines corresponding to transitions from SO2 and HC3N. These 6 new lines are CH3OH[1(1) - 1(0)E], CH3OH[2(1) - 2(0)E], CH3OH[3(1) - 3(0)E], CH3OH[4(1) - 4(0)E], SO2[14(1, 13) -14(0, 14)] and HC3N[18 -17]. We applied a rotation diagram analysis to derive rotation temperatures and column densities from the methanol transitions detected, and combined with NRAO 12-m data from Slysh et al. 1999. Applying a two-component fit, we find a cold component with temperature 13-16K and column density 3.3-3.4 ×10 14 cm-2, and a hot component with temperature 64 - 83K and column density 9.3×10 14 - 9.7 ×10 14 cm-2. On the other hand, applying just a one-component fit yields temperatures in the 47 -62 K range and column densities from 7.5-1.1 × 10 15 cm-2.

Nearly simultaneous observations for 28SiO v=0, 1, 2, J =3-2 transitions in 39 late-type stars have been carried out in February 1995 and 1996 with the 14 m radio telescope at Taeduk Radio Astronomy Observatory (TRAO). Observations for 28SiO v=0, 1, 2, J=2-1 lines in the same objects have been also carried out in March 1995 and March-April 1996. The detection rate of 28SiO v=l, J=3-2 line for the 28SiO v=l, J=2-1 sources was 59%. Seventeen new detections in the 28SiO v=l, J=3-2 transition and 4 new detections in the 28SiO v=2, J=3-2 transition have been reported including the intensity ratios within the vibrational ladders and rotational states.