2013/09/04 by Michal Bilek, M. Bílek, B. Jungwiert +9
Physics and Astronomy · #Astronomy and Astrophysical Research #Bulge #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Limit (mathematics) #Mass distribution #Modified Newtonian dynamics #Shell (structure) #Spiral galaxy #Stars #Stellar, planetary, and galactic studies #astro-ph.CO
paper · pdf · doi:10.1051/0004-6361/201322060
8 pages, 3 figures, Accepted for publication in A&A
openalex publication_date 2013/09/04 · arxiv created 2013/09/13 · arxiv updated 2015/06/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Context. The elliptical galaxy NGC 3923 is surrounded by numerous stellar shells that are concentric arcs centered on the Galactic core. They are very likely a result of a minor merger and they consist of stars in nearly radial orbits. For a given potential, the shell radii at a given time after the merger can be calculated and compared to observations. The MOdified Newtonian Dynamics (MOND) is a theory that aims to solve the missing mass problem by modifying the laws of classical dynamics in the limit of small accelerations. Hernquist & Quinn (1987b, ApJ, 312, 1) claimed that the shell distribution of NGC 3923 contradicted MOND, but Milgrom (1988, ApJ, 332, 86) found several substantial insufficiencies in their work.