The study of galaxies is of utmost importance for the study of the Universe, provided that the largest part of its content cannot be directly observed. One of the biggest question regarding galaxy evolution is how their properties, such as their morphology, are aected by their local environment, specically the density of the region where they seem to appear. In the local Universe studies have shown that elliptical galaxies are found predominantly in the central regions of galaxy clusters, where densities are higher, while disk galaxies reside in regions of lower densities such as the edges of clusters. We investigate if this pattern continues to exist at earlier times, by using the CANDELS collaboration data up to redshift of z 3. For this, we make use of the photometric redshift probability distributions (photo-z PDFs), after we apply statistical methods to improve their quality. Additionally, we use 3D-HST grism redshifts as well as spectroscopic redshifts where available, which are all selected
to have the best quality possible. Furthermore, we use morphological catalogs provided by the CANDELS team, to select galaxies from three main categories: spheroid, disk, and irregular galaxies. We investigate the clustering signal of these dierent morphological types by estimating two-point cross correlation functions of each type with the full sample of galaxies. Our results show that spheroid galaxies continue to cluster more strongly than disk galaxies at small separations, while at larger separations the dierence in the signal is no longer statistically signicant. This continues to be the case even at higher redshift bins, with the highest redshift bins being too noisy to have a conclusive answer.
GALAXY DENSITY-MORPHOLOGY RELATION AT HIGH REDSHIFT WITH CANDLES
Jeffrey A Newman