Properties of the ionized gas in HH202. I: Results from integral field spectroscopy with PMAS
Abstract
We present results from integral field spectroscopy with the Potsdam multi-Aperture Spectrograph of the head of the Herbig-Haro object HH 202 with a spatial sampling of 1"x1". We have obtained maps of different emission lines, physical conditions --such as electron temperature and density-- and ionic abundances from recombination and collisionally excited lines. We present the first map of the Balmer temperature and of the temperature fluctuation parameter, t2. We have calculated the t2 in the plane of the sky, which is substantially smaller than that determined along the line of sight. We have mapped the abundance discrepancy factor of O2+, ADF(O2+), finding its maximum value at the HH 202-S position. We have explored the relations between the ADF(O2+) and the electron density, the Balmer and [O III] temperatures, the ionization degree as well as the t2 parameter. We do not find clear correlations between these properties and the results seem to support that the ADF and t2 are independent phenomena. We have found a weak negative correlation between the O2+ abundance determined from recombination lines and the temperature, which is the expected behaviour in an ionized nebula, hence it seems that there is not evidence for the presence of super-metal rich droplets in H II regions.