2010/09/01 by J. S. Gallagher, John S. Gallagher III, Angela Parker · 6 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Hubble sequence #Lenticular galaxy #Physics #Star formation #Stellar, planetary, and galactic studies #astro-ph.CO
paper · pdf · doi:10.1088/0004-637x/722/2/1962
published in The Astrophysical Journal 722(2), 1962-1969 (IOP Publishing) · 20 pages, 6 figures and 1 table, accepted for publication in The Astrophysical Journal
arxiv created 2010/09/01 · openalex publication_date 2010/10/05 · arxiv updated 2015/05/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Arp 104 is a pair of luminous interacting galaxies consisting of NGC 5216, an elliptical, and NGC 5218, a disturbed disk galaxy and joined by a stellar bridge. We obtained optical imaging to support photometric and color studies of the system. NGC 5216 lies on the red sequence, while the unusual distribution of stellar population properties in combination with intense central star formation in a dusty region result in NGC 5218 being a nearby example of an intermediate color (green valley) system. The stellar bridge has remarkably uniform optical surface brightness, with colors consistent with its stars coming from the outskirts of NGC 5218, but is relatively gas-poor while the northern tidal tail is rich in H i . While both galaxies contain shells, the shell structures in NGC 5218 are pronounced, and some appear to be associated with counter-rotating gas. This combination of features suggests that Arp 104 could be the product of distinct multiple interactions in a small galaxy group, possibly resulting from a hierarchical merging process, and likely leading to the birth of a relatively massive and isolated early-type galaxy.