We examine the inner mass distribution of the relaxed galaxy cluster Abell 383 ( z = 0.189 ) , in deep 16-band HST/ACS+WFC3 imaging taken as part of the CLASH multi-cycle treasury program .
Our program is designed to study the dark matter distribution in 25 massive clusters , and balances depth with a wide wavelength coverage , 2000–16000Å , to better identify lensed systems and generate precise photometric redshifts .
This photometric information together with the predictive strength of our strong-lensing analysis method identifies 13 new multiply-lensed images and candidates , so that a total of 27 multiple-images of 9 systems are used to tightly constrain the inner mass profile gradient , d \log \Sigma / d \log r \simeq - 0.6 \pm 0.1 ( r < 160 kpc ) .
We find consistency with the standard distance-redshift relation for the full range spanned by the lensed images , 1.01 < z < 6.03 , with the higher redshift sources deflected through larger angles as expected .
The inner mass profile derived here is consistent with the results of our independent weak-lensing analysis of wide-field Subaru images , with good agreement in the region of overlap ( \sim 0.7 - 1 arcmin ) .
Combining weak and strong lensing , the overall mass profile is well fitted by an NFW profile with M _ { vir } = ( 5.37 ^ { +0.70 } _ { -0.63 } \pm 0.26 ) \times 10 ^ { 14 } M _ { \odot } / h and a relatively high concentration , c _ { vir } = 8.77 ^ { +0.44 } _ { -0.42 } \pm 0.23 , which lies above the standard c – M relation similar to other well-studied clusters .
The critical radius of Abell 383 is modest by the standards of other lensing clusters , r _ { E } \simeq 16 \pm 2 \arcsec ( for z _ { s } = 2.55 ) , so the relatively large number of lensed images uncovered here with precise photometric redshifts validates our imaging strategy for the CLASH survey .
In total we aim to provide similarly high-quality lensing data for 25 clusters , 20 of which are X-ray selected relaxed clusters , enabling a precise determination of the representative mass profile free from lensing bias .