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arXiv · 0905.3982

Environmental Effects on the Star Formation Activity in Galaxies at z=1.2 in the COSMOS Field

Y. Ideue·T. Nagao·Y. Taniguchi·Y. Shioya·T. Saito·T. Murayama·S. S. Sasaki·J. R. Trump·A. M. Koekemoer·H. Aussel·P. Capak·O. Ilbert·H. McCracken·B. Mobasher·M. Salvato·D. B. Sanders·N. Scoville
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Abstract

We investigate the relation between the star-formation activity in galaxies and environment at z=1.2 in the COSMOS field, using the fraction of [OII] emitters and the local galaxy density. The fraction of [OII] emitters appears to be almost constant over the surface density of galaxies between 0.2 and 10 Mpc^-2. This trend is different from that seen in the local universe where the star-formation activity is weaker in higher density regions. To understand this difference between z~1 and z~0, we study the fraction of non-isolated galaxies as a function of local galaxy density. We find that the fraction of non-isolated galaxies increases with increasing density. Our results suggest that the star formation in galaxies at z~1 is triggered by galaxy interaction and/or mergers.

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Y. Ideue, T. Nagao, Y. Taniguchi, Y. Shioya, T. Saito, T. Murayama, S. S. Sasaki, J. R. Trump, A. M. Koekemoer, H. Aussel, P. Capak, O. Ilbert, H. McCracken, B. Mobasher, M. Salvato, D. B. Sanders, N. Scoville. 2009-05-27. Environmental Effects on the Star Formation Activity in Galaxies at z=1.2 in the COSMOS Field. https://doi.org/10.1088/0004-637x%2F700%2F2%2F971

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