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arXiv · 1802.00133

Thirty-fold: Extreme gravitational lensing of a quiescent galaxy at $z=1.6$

H. Ebeling·M. Stockmann·J. Richard·J. Zabl·G. Brammer·S. Toft·A. Man
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Abstract

We report the discovery of eMACSJ1341-QG-1, a quiescent galaxy at $z=1.594$ located behind the massive galaxy cluster eMACSJ1341.9$-$2442 ($z=0.835$). The system was identified as a gravitationally lensed triple image in Hubble Space Telescope images obtained as part of a snapshot survey of the most X-ray luminous galaxy clusters at $z>0.5$ and spectroscopically confirmed in ground-based follow-up observations with the ESO/X-Shooter spectrograph. From the constraints provided by the triple image, we derive a first, crude model of the mass distribution of the cluster lens, which predicts a gravitational amplification of a factor of $\sim$30 for the primary image and a factor of $\sim$6 for the remaining two images of the source, making eMACSJ1341-QG-1 by far the most strongly amplified quiescent galaxy discovered to date. Our discovery underlines the power of SNAPshot observations of massive, X-ray selected galaxy clusters for lensing-assisted studies of faint background populations.

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H. Ebeling, M. Stockmann, J. Richard, J. Zabl, G. Brammer, S. Toft, A. Man. 2018-02-01. Thirty-fold: Extreme gravitational lensing of a quiescent galaxy at $z=1.6$. https://doi.org/10.3847/2041-8213/aa9fee

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