2010/07/21 by Néstor Sánchez, Nestor Sanchez, Neyda Anez +4
Mathematics · Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Fractal #Fractal dimension #Galaxies: Formation, Evolution, Phenomena #Galaxy #Interstellar medium #Mathematics #Milky Way #Molecular cloud #Physics #Scale (ratio) #Spatial distribution #Star cluster #Stars #Statistics #Stellar, planetary, and galactic studies #astro-ph.CO
paper · pdf · doi:10.1088/0004-637x/720/1/541
published as The Astrophysical Journal, Volume 720, Issue 1, pp. 541-547 (2010) · 18 pages including 4 figures. Accepted for publication in ApJ
arxiv created 2010/07/21 · openalex publication_date 2010/08/11 · arxiv updated 2010/11/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the distribution of stars, H ii regions, molecular gas, and individual giant molecular clouds in M33 over a wide range of spatial scales. The clustering strength of these components is systematically estimated through the fractal dimension. We find scale-free behavior at small spatial scales and a transition to a larger correlation dimension (consistent with a nearly uniform distribution) at larger scales. The transition region lies in the range ∼500–1000 pc. This transition defines a characteristic size that separates the regime of small-scale turbulent motion from that of large-scale galactic dynamics. At small spatial scales, bright young stars and molecular gas are distributed with nearly the same three-dimensional fractal dimension ( D f ,3D ≲ 1.9), whereas fainter stars and H ii regions exhibit higher values, D f ,3D ≃ 2.2–2.5. Our results indicate that the interstellar medium in M33 is on average more fragmented and irregular than in the Milky Way.