Trigonometric parallaxes of star forming regions in the Sagittarius
  spiral arm
  We report measurements of parallaxes and proper motions of ten high-mass
star-forming regions in the Sagittarius spiral arm of the Milky Way as part of
the BeSSeL Survey with the VLBA. Combining these results with eight others from
the literature, we investigated the structure and kinematics of the arm between
Galactocentric azimuth around -2 and 65 deg. We found that the spiral pitch
angle is 7.3 +- 1.5 deg; the arm's half-width, defined as the rms deviation
from the fitted spiral, is around 0.2 kpc; and the nearest portion of the
Sagittarius arm is 1.4 +- 0.2 kpc from the Sun. Unlike for adjacent spiral
arms, we found no evidence for significant peculiar motions of sources in the
Sagittarius arm opposite to Galactic rotation.
