Ponente
Descripción
Strong lenses are systems in which the light from a background source is deflected by a foreground galaxy or group of galaxies, resulting in multiple images of the background source. These images are also usually heavily distorted, acquiring the shape of rings or arcs. Study of these images provides us unique information about the distribution of matter (baryonic plus dark) within the foreground mass acting as a lens. This information allows us, for instance, to constrain galaxy mass models, the stellar initial mass function or the abundance of dark matter subhaloes. Strong lensing is therefore a major cosmological tool. In this work we focus our attention to MACS J1206 galaxy cluster at z = 0.44 and 82 spectroscopic multiple images caused by it, which belong to 27 background galaxies at redshifts between 1.01 and 6.06. 11 of these multiple images are found within the 50 kpc of the brightest cluster galaxy (BCG) and two great arcs (one straight and other curved) can clearly be seen arising from the BCG. These are suitable conditions to use a non-parametric method, which requires a sufficiently large number of lensed images as constraints. Accordingly, we have performed a non-parametric strong lensing analysis with the positional measurements of these multiple images in order to estimate an accurate total mass distribution (with baryonic and dark components) in the center of this galaxy cluster.
