Distribution of large-scale filaments with respect to spiral arms. The top panel is a longitude-velocity view of filaments and spiral arms. Belts with various colors are arms in Taylor & Cordes (1993) model, and widths are 10 km s⁻¹. Red, brown, blue, and green represent the Norma-Outer, Scutum-Centaurus, Sagittarius-Carina, and Perseus arms, respectively. Black circles denote our filaments and stars are “bones”. The bottom panel shows a face-on view of filaments and spiral arms. The cyan plus symbol represents the Galactic center, and grey dashed lines show the data range. The solar symbol ⊙ is plotted at (0, 8.15) kpc (Reid et al. 2019).