ALMA observations of submillimeter H2O and SiO lines in Orion Source I
  We present observational results of the submillimeter H2O and SiO lines
toward a candidate high-mass young stellar object Orion Source I using ALMA.
The spatial structures of the high excitation lines at lower-state energies of
>2500 K show compact structures consistent with the circumstellar disk and/or
base of the northeast-southwest bipolar outflow with a 100 au scale. The
highest excitation transition, the SiO (v=4) line at band 8, has the most
compact structure. In contrast, lower-excitation transitions are more extended
than 200 au tracing the outflow. Almost all the line show velocity gradients
perpendicular to the outflow axis suggesting rotation motions of the
circumstellar disk and outflow. While some of the detected lines show broad
line profiles and spatially extended emission components indicative of thermal
excitation, the strong H2O lines at 321 GHz, 474 GHz, and 658 GHz with
brightness temperatures of >1000 K show clear signatures of maser action.
