2008A&A...485..435P

We present a BVRI CCD (Charge Coupled Device) surface photometry analysis of the galaxy group NGC4410, which contains four galaxies in interaction. Along with our photometric study, we show residual images (after subtracting isophotal models) and unsharp masked images to uncover any hidden structures in this system of galaxies; we have also performed a two-dimensional bulge-disk decomposition for NGC4410C and D, and a major axis sector profile for NGC4410A. We have calculated BVRI surface brightnesses and colors within regions such as galaxy centers, bridges, tails and optical knots in the NGC4410 system, generating B-V color maps and color profiles. The information obtained was used to discover the predominant stellar populations. The colors of the galaxies imply ages of ∼2x10⁹ to ∼2x10¹⁰years for models using a range of metallicities. The bluer knots and HII regions have colors implying ages of a minimum of 5x10⁸years, but possibly as high as 3x10 ⁹ years for stellar populations formed in the interaction. These results lead us to conclude that there is a moderate star formation rate and a tranquil evolving state of the system with a long timescale for interaction, much longer than the typical dynamical timescales of 10⁸ years. Although we note that NGC4410D has a blue nucleus (possible nuclear starburst?), bulge, bar, and short spiral arms, and may be interacting with a HI gas cloud. Some observed structures in NGC4410A are coincident with previously studied HII regions, a tidal arm and optical/radio knots found in this galaxy. An optical knot E coincident with a radio knot may be an optical synchrotron emission or an HII region. The galaxy NGC4410B appears to be a boxy giant elliptical with a possible dusty disk embedded (similar to Cen A?) and NGC4410C is confirmed as a lenticular galaxy.