A study of HII regions in spiral galaxies using multiobject spectroscopy
Multiobject spectroscopy results of HII regions in nearby late-type spiral galaxies are given. Results include excitation measurements, log ((O III)/H beta), for 81 regions in M 101, 30 regions in NGC 2403, and 13 regions in M 51. Researchers conclude that late-type spirals can be classified into two distinct populations, examine possible causes of this division, and derive metallicity gradients for these galaxies. M 51 appears to have an anomalously shallow abundance gradient.
Zaritsky, Dennis↗