Powerful lens galaxy cluster PLCK G287.0+32.9

We also identified 114 multiple images from 28 background sources, of which 84 images from 16 sources are new and the remaining ones have already been identified in previous works. From these, we extracted 'golden sample' of 47 secure multiple images and used them, together with the selected cluster member, to build and optimize several strong-lensing models with the software lenstool. The best-fitting lens model shows a root mean square (RMS) separation value between the predicted and observed positions of the multiple images of 0.75".

Using its predictive power, we found three new multiple images and we confirm the configuration of three systems of multiple images that were not used for the optimization of the model. For a source at a redshift of zs=2, we found a cluster with an Einstein radius of theta_E_=43.4+/-0.1". This value is in agreement with previous estimates and corresponds to a total mass enclosed in the critical curve of M_E_=3.33_-0.07_^+0.02^x10^14^M_{sun}_.

The combined application of ancillary Hubble Space Telescope (HST) imaging, VIMOS and DEIMOS data, and the new MUSE spectroscopic observations allowed us to build a new lens model of the galaxy cluster PLCK G287.0+32.9, with an improvement in terms of reconstructing the observed positions of the multiple images of a factor of 2.5 with respect to previous models. The derived total mass distribution confirms this cluster to be a very prominent gravitational lens, with an effective Einstein radius of theta_E_~43".

We were also able to construct an extensive spectroscopic catalog containing 490 objects, of which 153 are bright cluster members with m_F160W_<=21, and 114 are multiple images.