1998/08/17 by Paul B. Eskridge, Richard W. Pogge, Eskridge, Paul B. +1
Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9808169
to appear in Star Formation in Early-Type Galaxies, ASP Conf Ser., eds. P. Carral & J. Cepa paspconf.sty LaTeX, 6 pages, 3 figures
arxiv created 1998/08/17 · openalex publication_date 1998/08/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Polar-ring galaxies are systems with two nearly orthogonal rotational axes, and are therefore clearly the result of galaxy-galaxy interactions. The host galaxies of polar rings are typically gas-poor early-type systems. The rings themselves, however, are typically gas-rich, blue, star-forming systems. They have traditionally been modelled as the remnants of accreted dwarf irregular galaxies. Published results on the molecular gas content, and nebular abundances argue against this model. We present H-alpha imaging data for three polar-ring galaxies, and derive their HII region luminosity functions. In all three galaxies, the HII region luminosity functions are much steeper than found for any dwarf galaxy. The slopes are generally closer to those of Sa galaxies. Thus the HII region LFs of polar rings join the ISM abundances in resembling the very earliest-type spirals galaxies, rather than their supposed dwarf irregular precursors.