Velocity-coherent filaments in Orion B identified with the FoF algorithm. (a) Morphologies of the filaments. The filament names are labeled with the same colors as each filament. (b) The distribution of velocity centroids ranges from 7.8–11.5 km s⁻¹ within identified filaments. (c) The spines of each filament are drawn with thick lines. (d) The distribution of YSOs identified and classified in Furlan et al. (2016). Red asterisk symbol: Class 0 protostars. Green asterisk symbol: Class I protostars. Yellow asterisk symbol: flat-spectrum YSOs. The colored contours delineate the filaments identified in this study. Gray tones in the two lower panels indicate the distribution of the integrated intensity of C¹⁸O (1–0) line.