1999/06/14 by Yoshiaki Sofue, Sofue, Yoshiaki
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9906224
Postscript 4 pages, incl. figures: To apper in the proc. of XIXth Moriond Astrophysics Meeting ``Building Galaxies: from the Primordial Universe to the Present'' held at Les Arcs, March 13-20 1999, ed. F.Hammer et al (Editions Frontieres)
arxiv created 1999/06/14 · openalex publication_date 1999/06/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present high-accuracy rotation curves, which show a steep nuclear rise and high-velocity central rotation, followed by a broad maximum in the disk and flat part. We use the rotation curves to directly calculate the radial distribution of surface mass density, and obtain radial variations of the mass-to-luminosity ratio (M/L). The M/L ratio and, therefore, the dark mass fraction (DMF) is not constant at all, but varies within the bulge, increases already within the disk, and rapidly from the disk toward halo. In some galaxies, the DMF within the bulge increases inward toward the center, indicating a massive dark core.