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arXiv · 1412.5188

The reversal of the SF-density relation in a massive, X-ray selected galaxy cluster at z=1.58: results from Herschel

Joana S. Santos·. Bruno Altieri·Ivan Valtchanov·Alessandro Nastasi·Hans Böhringer·Giovanni Cresci·David Elbaz·Rene Fassbender·Piero Rosati·Paolo Tozzi·Miguel Verdugo
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Abstract

Dusty, star-forming galaxies have a critical role in the formation and evolution of massive galaxies in the Universe. Using deep far-infrared imaging in the range 100-500um obtained with the Herschel telescope, we investigate the dust-obscured star formation in the galaxy cluster XDCP J0044.0-2033 at z=1.58, the most massive cluster at z >1.5, with a measured mass M200= 4.7x10$^{14}$ Msun. We perform an analysis of the spectral energy distributions (SEDs) of 12 cluster members (5 spectroscopically confirmed) detected with >3$σ$ significance in the PACS maps, all ULIRGs. The individual star formation rates (SFRs) lie in the range 155-824 Ms/yr, with dust temperatures of 24$\pm$35 K. We measure a strikingly high amount of star formation (SF) in the cluster core, SFR (< 250 kpc) > 1875$\pm$158 Ms/yr, 4x higher than the amount of star formation in the cluster outskirts. This scenario is unprecedented in a galaxy cluster, showing for the first time a reversal of the SF-density relation at z~1.6 in a massive cluster.

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Joana S. Santos, . Bruno Altieri, Ivan Valtchanov, Alessandro Nastasi, Hans Böhringer, Giovanni Cresci, David Elbaz, Rene Fassbender, Piero Rosati, Paolo Tozzi, Miguel Verdugo. 2014-12-16. The reversal of the SF-density relation in a massive, X-ray selected galaxy cluster at z=1.58: results from Herschel. https://doi.org/10.1093/mnrasl%2Fslu180

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