Distance to the Brick cloud using stellar kinematics

Context. The central molecular zone at the Galactic center is currently being studied intensively to understand how star formation proceeds under extreme conditions of a galactic nucleus. Knowing position clouds along line sight toward has had important implications in our understanding physics gas and zone.It was recently claimed that dense cloud G0.253 + 0.016 (the Brick) distance $\sim$7.20 kpc from Sun. That would place it outside zone, therefore nuclear stellar disk, but still inside Bulge. Aims. Theoretical considerations as well observational studies show stars belong disk have different kinematics those inner Therefore, we aim constrain Brick by studying proper motions area. Results. population seen shows following three kinematic components: 1) Bulge with an isotropic velocity dispersion $\sim$3.5 micro-arc second per year; 2) eastward moving on near side disk; 3) westward far disk. We clearly see all components comparison field. However, Brick, which blocks light behind it, can only 2). Conclusions. While detection significant component streaming implies must be located and, therefore, forms part zone.