Sample of minor merger of galaxies: Optical CCD surface photometry and HII region properties

Miriani G. Pastoriza¹
Diego Ferreiro²

1) IF/UFRGS (2) IATE, Observatorio Astronómico, Universidad Nacional de Córdoba, Argentina

We present the results of the B, V and I photometry of eleven southern minor mergers. We built B, V, and I equivalent profiles for each galaxy and decomposed them into bulge and disk components when possible. From H[EQUATION]+N[II] images we have estimated the basic photometric parameters of the HII regions, such as position, size, B-V and V-I colours, H[EQUATION]+[NII] luminosity and [EQUATION] equivalent width. Primary components have blue absolute magnitudes in the range -22 [EQUATION] -18, with a peak at [EQUATION] = - 22. The magnitudes of the secondary components are in the range -22 [EQUATION] -16 with a maximum at [EQUATION] = - 19. We found a linear correlation between the luminosity ratios of the components and their ratio of major diameters, leading to mass ratios between 0.04 [EQUATION] [EQUATION] [EQUATION]/[EQUATION] [EQUATION] [EQUATION] 0.2, suggesting indeed that our sample is formed by minor mergers. Most of the HII regions and evolved star-forming regions of the sample were formed between 3.6 to 13.7 Myr ago with an average of (6.3[EQUATION]0.7) Myr. The HII regions have log(H[EQUATION]+[NII]) luminosity between 38.6 and 41.7 and the luminosity function for the whole sample fits a power law of index [EQUATION] = -1.33. The linear correlation between the luminosity [EQUATION](H[EQUATION]+[NII]) and the size of the HII regions has slope of 2.12[EQUATION]0.06. We will use the Gemini with GMOS to study the kinematic and metal abundance of the HII region sample.