The Parallax and 3D Kinematics of Water Masers in the Massive Star-forming Region G034.43+0.24

We report a measurement of the trigonometric parallax of 22 GHz water masers in the massive star-forming region G034.43+0.24 as part of the Bar and Spiral Structure Legacy Survey using the Very Long Baseline Array. The parallax is 0.330 +/- 0.018 mas, corresponding to a distance of 3.03(-0.16)(+0.17) kpc. This locates G034.43+0.24 near the inner edge of the Sagittarius spiral arm and at one end of a linear distribution of massive young stars that cross nearly the full width of the arm. The measured three-dimensional motion of G034.43+0.24 indicates a near-circular Galactic orbit. The water masers display arc-like distributions, possibly bow shocks, associated with winds from one or more massive young stars.

Automated summary

We present the measurement of the trigonometric parallax of 22 GHz water masers in the massive star-forming region G034.43+0.24. The obtained parallax corresponds to a distance of 3.03(-0.16)(+0.17) kpc. The motion and distribution of water masers in the region provide valuable insights into the structure and dynamics of the Sagittarius spiral arm.