ℓ–v diagram for objects in the new structure. Groups associated with single velocity peaks are filled symbols, while ambiguous cases are open symbols with dashed lines connecting plausible v_lsr solutions. The shape indicates the survey used to determine the v_lsr: SEDIGISM (circle), FUGIN (square), and COGAL (triangle). Masers are plotted as magenta “x” marks. The underlying image is the Dame et al. (2001) COGAL map integrated over |b|≤3°, with the loci of the Sagittarius Arm (orange line) and Scutum Arm (blue line) from Reid et al. (2016). Each YSO group in the structure has a possible solution consistent with the Sagittarius Arm.