Optical to Mid-Infrared Analysis for the Galaxy Group RSCG 44

Abstract

We present the detailed Optical to Mid Infrared (MIR) analysis on the compact group of galaxies RSCG44. The optical analysis comprehends both photometric andspectroscopic studies for six galaxies in this group. The overall Optical to MIR data provide maps, spectra, profiles and images to analyse galaxy properties (structure, line-strength features, etc.) of each member searching for signatures of star formation and nucleus activity. In the photometric analysis, we study $BVR$ surface brightness and colors calculated for regions such as galaxy centers, possible bridges, tails and optical knots. Optical direct image also presents residual images (after subtracting isophotal models) and unsharp masked images in order to uncover any hidden structure in the system. The inclusion of maps, profiles and images from the Spitzer Space Telescope (SST) was made in order to provide a complementary outlook for the optical colors and the environment in which the group evolves, hence, a better explanation of the photospheric component and possible photdissociation regimes in polycyclic aromatic hydrocarbon (PAH) emission at 5.8 and 8 μm have provide a disentangled view of dust properties in the interstellar medium (ISM) at MIR. Optical spectra for the group are also provided to establish a more fond comparison between optical to mid infrared properties. The color gradients were compared with the optical spectra of both galaxies, showing in general similar trends for star formation. Globally, color maps, color tables and optical spectra indicate predominant stellar populations from classes I, III and V corresponding to spectral types of K-M stars with ages of at least in theorder of 10 Gyr for models using metallicity ranges with solar and non solar abundances. These results lead us to the conclusion of a moderate star formation rate and a tranquil evolving state of the system.