.:Conclusions:.

--Environmental Factors--

-Changes in SFR due to Morphology-

I found that in both cluster and non-cluster members that the average SFR of certain HST types follows the trend of having elliptical type galaxies with mid-range SFRs, followed by a sudden spike in the SFR of early type spiral galaxies, ending with a gradual downward trend in SFR from late type spirals to irregular galaxies.

The fall of SFR from early type spirals to irregular galaxies can possibly be explained due to the shape of the galaxies themselves. In early type spirals, the arms are numerous and tightly wound, as is the gas and dust, and stars form readily. However, later type spirals have fewer arms and are more tapered, which in some cases should have more young stars[1]. This can be explained by active galactic nuclei, strong sources of radiation in the centers of some galaxies. These emit over all different wavelengths, including the infrared, so the observed 24-micron flux yields a higher value of SFR than is actually present. AGN are more prominent in early type spiral galaxies due to their large central bulges. The large difference in the SFRs of elliptical galaxies and early type spiral galaxies makes sense due to elliptical galaxies containing low amounts of interstellar matter, which includes gas and dust to condense and form stars.

-Changes in SFR due to Color-

I found that overall bluer galaxies tended to have higher SFRs. However, since galaxies with high SFR have lots of dust, and dust makes the galaxy redder, this result seems to cast some doubt. It could be that the reddest galaxies are elliptical, and thus have redder stars (not much dust) and little cool gas to form stars.  Even so, the correlation was not as strong as expected due to interpretation constraints: there was a small sampling size of galaxies in certain index groups, and I could not viably quantify the errors in the R and I bands.