TITLE:
Optical to Mid-Infrared Analysis for the Galaxy Group RSCG 44
AUTHORS:
J. A. Pérez-Grana, S. N. Kemp, J. P. Phillips
KEYWORDS:
Galaxy; Photometry Galaxy; Spectroscopy Galaxy; Interactions Galaxies; Evolution
JOURNAL NAME:
International Journal of Astronomy and Astrophysics,
Vol.4 No.1,
March
7,
2014
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.