Clustering of the AKARI NEP Deep Field mid infrared selected galaxies

Aleksandra Solarz, Agnieszka Pollo, Tsutomu T. Takeuchi and Katarzyna Małek

We present a method of selection of 24μm galaxies from the AKARI North Ecliptic Pole (NEP) Deep Field and measurements of their two-point correlation function. We aim to associate different 24μm selected galaxy populations with present day galaxies, and to investigate the impact of their environment on the direction of their subsequent evolution. We discuss the use of Support Vector Machines (SVM) algorithms applied to infrared photometric data to perform star-galaxy separation, in which we achieve an accuracy > 80%. We explore the redshift dependance of the correlation function parameters as well as the linear bias evolution (which relates galaxy distribution to the one of the underlying dark matter). We find that the bias parameter increases slowly with redshift, from b = 0.9 at z < 0.5 to b ~1.9 at z ~1.1. Total infrared luminosities (L_TIR) found for different samples, suggest that galaxies with higher L_TIR do not necessarily reside in higher mass dark matter halos. We find that luminous infrared galaxies (LIRGs) at z~1 can be ancestors of present day L_* early type galaxies.

Proceedings of the Polish Astronomical Society, vol. 3, 186-191 (2016)

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