Abell 611. I. Weak lensing analysis with LBC

Aims: The Large Binocular Cameras (LBC) are two twin wide field cameras (FOV ~ 23' × 25') mounted at the prime foci of the 8.4 m Large Binocular Telescope (LBT). We performed a weak lensing analysis of the z = 0.288 cluster Abell 611 on g-band data obtained by the blue-optimized LBC in order to estimate the cluster mass.
Methods: Owing to the complexity of the PSF of LBC, we decided to use two different approaches, KSB and shapelets, to measure the shape of background galaxies and to derive the shear signal produced by the cluster. Then we estimated the cluster mass with both aperture densitometry and parametric model fits.
Results: The combination of the large aperture of the telescope and the wide field of view allowed us to map a region well beyond the expected virial radius of the cluster and to get a high surface density for background galaxies (23 galaxies/arcmin²). This made it possible to estimate an accurate mass for Abell 611. We find that the mass within 1.5 Mpc is (8±3)× 10¹⁴ M_⊙ from the aperture mass technique and (5±1)× 10¹⁴ M_⊙ using the model fitting by an NFW mass density profile for both shapelet and KSB methods. This analysis demonstrates that LBC is a powerful instrument for weak gravitational lensing studies.