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arXiv · 1606.07439

A weak lensing view of the downsizing of star-forming galaxies

Yousuke Utsumi·Margaret J. Geller·Ian P. Dell'Antonio·Yukiko Kamata·Satoshi Kawanomoto·Michitaro Koike·Yutaka Komiyama·Shintaro Koshida·Sogo Mineo·Satoshi Miyazaki·Jyunya Sakurai·Philip J. Tait·Tsuyoshi Terai·Daigo Tomono·Tomonori Usuda·Yoshihiko Yamada·Harus J. Zahid
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Abstract

We describe a weak lensing view of the downsizing of star forming galaxies based on cross correlating a weak lensing ($\kappa$) map with a predicted map constructed from a redshift survey. Moderately deep and high resolution images with Subaru/Hyper Suprime-Cam covering the 4 deg^2 DLS F2 field provide a $\kappa$ map with 1 arcmin resolution. A dense complete redshift survey of the F2 field including 12,705 galaxies with $R\leq20.6$ is the basis for construction of the predicted map. The zero-lag cross-correlation between the \kappa and predicted maps is significant at the $30\sigma$ level. The width of the cross-correlation peak is comparable with the angular scale of rich cluster at $z\sim0.3$, the median depth of the redshift survey. Slices of the predicted map in $\delta{z} = 0.05$ redshift bins enable exploration of the impact of structure as a function of redshift. The zero-lag normalised cross-correlation has significant local maxima at redshifts coinciding with known massive X-ray clusters. Even in slices where there are no known massive clusters, there is significant signal in the cross-correlation originating from lower mass groups that trace the large-scale of the universe. Spectroscopic $D_n4000$ measurements enable division of the sample into star-forming and quiescent populations. The significance of the cross-correlation with structure containing star-forming galaxies increases with redshift from $5\sigma$ at $z = 0.3$ to $7 \sigma$ at $z = 0.5$. The weak lensing results are consistent with the downsizing view of galaxy evolution established on the basis of many other independent studies.

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Yousuke Utsumi, Margaret J. Geller, Ian P. Dell'Antonio, Yukiko Kamata, Satoshi Kawanomoto, Michitaro Koike, Yutaka Komiyama, Shintaro Koshida, Sogo Mineo, Satoshi Miyazaki, Jyunya Sakurai, Philip J. Tait, Tsuyoshi Terai, Daigo Tomono, Tomonori Usuda, Yoshihiko Yamada, Harus J. Zahid. 2016-06-23. A weak lensing view of the downsizing of star-forming galaxies. https://doi.org/10.3847/1538-4357%2F833%2F2%2F156

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