Abstract Extinction maps are essential for tracing interstellar dust and enabling accurate stellar population studies in galaxies. Here, a high-resolution extinction distribution of the nearby Triangulum galaxy (M33), is constructed by fitting multiband color indexes of the individually resolved red-giant-branch stars from the Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region survey. Achieving an angular resolution of approximately 6″ (∼24.4 pc), the extinction map reveals the intricate and heterogeneous distribution of dust throughout the entire disk of M33, with distinct delineation of spiral arms, interarm regions, and compact dust clouds. In addition, it exhibits strong spatial correspondence with the distributions of total hydrogen, H I , and CO, underscoring the reliability of the extinction map for tracing both diffuse and dense components of the interstellar medium. The derived V -band extinction reaches up to 2.5 mag per pixel, with a mean value of about 1.05 mag. Beyond providing new insights into the dust structure of M33, the extinction map offers a robust foundation for accurate extinction corrections and will support future studies, including upcoming observations with the Chinese Space Station Telescope.
王 et al. (Tue,) studied this question.