Subaru FOCAS IFU observations of two z=0.12 strong-lensing elliptical galaxies from SDSS MaNGA

Understand

We present new observations of two z=0.12 strong-lensing elliptical galaxies, originally discovered from the SDSS-IV MaNGA survey, using the new FOCAS IFU spectrograph on the Subaru Telescope.

• For J1436+4943, our observations confirm the identification of this system as a multiple-image lens, in a cusp configuration, with Einstein radius $\theta_{Ein}$=2.0 arcsec.
• For J1701+3722, the improved data confirm earlier hints of a complex source plane, with different configurations evident in different emission lines.
• The new observations reveal a previously unseen inner counter-image to the [OIII] arc found from MaNGA, leading to a smaller revised Einstein radius of $\theta_{Ein}$=1.6 arcsec.