We present a study of the H II regions in the central area of the giant irregular galaxy NGC 4449 based on observations taken on the William Herschel Telescope at the Roque de los Muchachos observatory with the Taurus II Fabry-Perot interferometer in the emission lines of Hα and [O III] 5006.8. We show that the usual methods of determining sizes of H II regions are not valid in this galaxy because of the high surface density of nebulae and the presence of an intense diffuse luminosity over NGC 4449, so it has been necessary to develop a new method. The procedure we have used allows integrated parameters of H II regions (radius, luminosity, radial velocity, and velocity dispersion) to be obtained with greater objectivity and precision than with other methods. The technique proposed here can be extended to parameterize giant H II regions in galaxies in general and to resolve the problem of the large uncertainties associated with previous methods in characterizing star-forming regions in Magellanic irregular galaxies.
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机译：我们基于在Roαde los Muchachos天文台的William Herschel望远镜和Taurus II Fabry-Perot干涉仪在Hα发射线上对William Herschel望远镜的观测结果，对巨型不规则星系NGC 4449的H II区进行了研究。 [O III] 5006.8。我们表明，由于星云的高表面密度和在NGC 4449上存在强烈的散射光度，确定H II区大小的常用方法在该星系中无效，因此有必要开发一种新方法。我们使用的程序允许以比其他方法更高的客观性和精度来获得H II区域的积分参数（半径，光度，径向速度和速度色散）。此处提出的技术可以扩展为一般性地参数化星系中的巨型H II区，并解决与表征麦哲伦不规则星系中恒星形成区的现有方法相关的较大不确定性的问题。
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