The environment of HII galaxies revisited

We present a study of the close (less than or similar to 200 h(75)(-1) kpc) environment of 110 relatively local (z less than or similar to 0.16) HII galaxies, selected from the Sloan Digital Sky Survey (SDSS; DR7). We use available spectroscopic and photometric redshifts to investigate the presence of a close and possibly interacting companion galaxy. Our aim is to compare the physical properties of isolated and interacting HII galaxies and investigate possible systematic effects in their use as cosmological probes. We find that interacting HII galaxies tend to be more compact, less luminous and have a lower velocity dispersion than isolated ones, in agreement with previous studies on smaller samples. However, as we verify, these environmental differences do not affect the cosmologically important L-H beta - sigma correlation of the HII galaxies.