%0 Journal Article
%T Studying the Interstellar Medium of H II/BCD Galaxies Using IFU Spectroscopy
%A Patricio Lagos
%A Polychronis Papaderos
%J Advances in Astronomy
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/631943
%X We review the results from our studies, and previous published work, on the spatially resolved physical properties of a sample of H II/BCD galaxies, as obtained mainly from integral-field unit spectroscopy with Gemini/GMOS and VLT/VIMOS. We confirm that, within observational uncertainties, our sample galaxies show nearly spatially constant chemical abundances similar to other low-mass starburst galaxies. They also show He II£¿£¿ 4686 emission with the properties being suggestive of a mix of excitation sources and with Wolf-Rayet stars being excluded as the primary ones. Finally, in this contribution, we include a list of all H II/BCD galaxies studied thus far with integral-field unit spectroscopy. 1. Introduction The concept of compact galaxies was introduced by Zwicky [1], who has described them as ¡°galaxies barely distinguishable from stars¡± on the Palomar Sky Survey plates. The term blue compact dwarf (BCD) galaxies [2] identify those objects that show low luminosity, small linear dimensions, strong emission lines superposed on a blue continuum, and spectral properties that indicate low chemical abundances. BCDs form a subset of H II galaxies, a large number of which have been identified on objective prism surveys by [3¨C6] by the presence of strong emission lines, similar to Giant H II regions (GH IIRs) in our galaxy. Here, we will refer to H II/BCD galaxies as objects with a metallicity (e.g., [7]), low luminosity ( ), and gas-rich objects (e.g., [8]) undergoing vigorous starburst activity in a relatively small physical size (£¿1£¿Kpc). The star forming component, in these objects, typically contains multiple knots of star-formation with unresolved ensembles of young star clusters (e.g., [9, 10]). The hypothesis of these systems being young, forming their first generation of stars, has been discarded by the detection of an evolved underlying stellar host with an age 1£¿Gyr, in the majority of the nearby H II/BCD population (e.g., [11, 12]). Figure 1 shows the optical spectrum of the galaxy Tol 2146-391 obtained using integral field unit (IFU) observations with Gemini/GMOS. In this figure, we label the most important emission lines used in our studies, in particular, the strong Balmer hydrogen recombination lines and collisionally excited emission lines, such as [O£¿II] 3726,3729, [O£¿III] 4363, [O£¿III] 5007, [S£¿II] 6717,6731, and [N£¿II] 6584, which have been used for the determination of physical conditions (e.g., electron temperature and density) and chemical abundances (e.g., oxygen, nitrogen, etc.). We also detect in some of our galaxies the
%U http://www.hindawi.com/journals/aa/2013/631943/