We summarize our results based on observations with the NIRI camera on the Gemini North telescope of three Hii galaxies (Mrk 36, UM 408 and UM 461), obtained to identify and determine the ages and masses of the elementary components (the star cluster population) of the starburst regions in compact Hii galaxies. Our preliminary results indicate that the masses of the stellar clusters in these galaxies range from ~104 to ~106 M⊙, with associated ages of a few Myr. The most massive star clusters fall in the so-called super star cluster category. The identification of these clusters suggests that the formation and evolution of massive star clusters is the dominant mode of star formation in these galaxies. Their spatial distribution and ages seem to indicate that star formation is simultaneous over these timescales in some of our objects. We also review our recent description of the spatial distribution of physical conditions in the Hii galaxy UM 408 using the GMOS integral-field unit on Gemini South. The spatial distribution of the oxygen abundance does not show any significant variation or gradient across the galaxy on scales of hundreds of parsecs, within our observational uncertainties, confirming that this compact Hii galaxy, like other previously studied dwarf irregular galaxies, is chemically homogeneous.

Local HII galaxies present a Fundamental Plane of [L–σ] where either the equivalent width of Hβ or the oxygen abundance O/H act as a second parameter. These relations are powerful cosmological distance indicators since emission line galaxies may be found to high redshifts, though some caution must be taken till systematic effects are better understood.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present the results of a spectrophotometric study of star forming regions in HII galaxies. In particular, we find that, besides their “blobbiness”, HII galaxies are quite homogenous in their chemical properties, though we do see important fluctuations in some physical properties (e.g. extinction).To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present a spectrophotometric survey of 111 H ii galaxies. Observations were made at the ESO 1.52m telescope, with the b&c spectrograph. Our sample presents a great overlap with Terlevich et al. 1991. Additional targets come from the Calan-Tololo an Marseille catalogues. All objects have been observed and analysed homogeneously. We analyse their statistical properties and derive physical conditions (reddening, electron temperature, electron density), as well as chemical abundances.

Stellar Clusters are identified in images and in the spectra of these star forming dwarf galaxies. These Stellar Clusters have properties similar to those observed in other violent star forming galaxies and may the elementary entities of a starburst.

SN1997ab belongs to a class of luminous type II SNe which are thought to be powered by the interaction of the shock wave with a dense circumstellar medium. We report the discovery of narrow P-Cygni profiles atop broad Balmer emission lines, an unambiguous signature of a dense and slow circumstellar wind due to mass loss in the final stages of the progenitor's life.

We present preliminary results of our near-infrared JHK images of a sample of H II galaxies observed at UKIRT. The presence of knots of enhanced emission in the near-IR may indicate the existence of luminous super star clusters which will serve to unveil the basic units which constitute the starburst phenomenon in galaxies. Based on near-IR colours we will further discuss the history of star formation in these bursting dwarf galaxies.

We report the first results of a multicolour (broad V,R,I and narrow [OIII] bands) surface photometry study of a small sample of HII galaxies.

The data were obtained at the 2.5m Nordic Optical Telescope (NOT) at La Palma, Canary Islands under subarcsecond seeing conditions. Part of the data has 0.55 arc seconds resolution (FWHM). The data will allow us to investigate the bi-parametric behaviour of the luminosity vs line-witdh relation.