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

Sep, 2004
28 pages
Published in:
  • Astron.Astrophys. 428 (2004) 837-846
e-Print:

Citations per year

200520072009201120131034
Abstract: (arXiv)
We present the results of the B, V and I photometry of eleven southern minor mergers. The total apparent B magnitude, integrated B-V and V-I colours were measured. We built B, V, and I equivalent profiles for each galaxy and decomposed them into bulge and disk components when possible. From Hα\alpha+N[II] images we have estimated the basic photometric parameters of the HII regions, such as position, size, B-V and V-I colours, Hα\alpha+[NII] luminosity and EW(Hα+[NII])EW(H\alpha+[NII]) equivalent width. 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 << M\cal M secondary/M_{secondary} / \cal M primary_{primary} << 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±\pm0.7) Myr. The HII region properties, luminosity, sizes and ages are similar in both components. The HII regions have log(Hα\alpha+[NII]) luminosity between 38.6 and 41.7. The HII region luminosity function for the whole sample fits a power law of index α\alpha = --1.33. The linear correlation between the luminosity L\cal L(Hα\alpha+[NII]) and the size of the HII regions has slope of 2.12±\pm0.06. We found that the disk of the primary component is more luminous than those of Lu's sample, while the disk of the secondary is smaller and fainter.
  • galaxies: photometry
  • galaxies: interactions
  • galaxies: irregular