THE GRISM LENS-AMPLIFIED SURVEY FROM SPACE (GLASS). VI. COMPARING THE MASS AND LIGHT IN MACS J0416.1-2403 USING FRONTIER FIELD IMAGING AND GLASS SPECTROSCOPY

A. Hoag, K.-H. Huang, T. Treu, M. Bradač, K. B. Schmidt, X. Wang, G. B. Brammer, A. Broussard, R. Amorin, M. Castellano, A. Fontana, E. Merlin (+3 others)
2016 Astrophysical Journal  
We present a strong and weak gravitational lens model of the galaxy cluster MACSJ0416.1-2403, constrained using spectroscopy from the Grism Lens-Amplified Survey from Space (GLASS) and Hubble Frontier Fields (HFF) imaging data. We search for emission lines in known multiply imaged sources in the GLASS spectra, obtaining secure spectroscopic redshifts of 31 multiple images belonging to 16 distinct source galaxies. The GLASS spectra provide the first spectroscopic measurements for 6 of the source
more » ... for 6 of the source galaxies. The weak lensing signal is acquired from 884 galaxies in the F606W HFF image. By combining the weak lensing constraints with 15 multiple image systems with spectroscopic redshifts and 9 multiple image systems with photometric redshifts, we reconstruct the gravitational potential of the cluster on an adaptive grid. The resulting total mass density map is compared with a stellar mass density map obtained from the deep Spitzer Frontier Fields imaging data to study the relative distribution of stellar and total mass in the cluster. We find that the projected stellar mass to total mass ratio, $f_{\star}$, varies considerably with the stellar surface mass density. The mean projected stellar mass to total mass ratio is $\langle f_{\star} \rangle= 0.009 \pm 0.003 $ (stat.), but with a systematic error as large as $0.004-0.005$, dominated by the choice of the IMF. We find agreement with several recent measurements of $f_{\star}$ in massive cluster environments. The lensing maps of convergence, shear, and magnification are made available to the broader community in the standard HFF format.
doi:10.3847/0004-637x/831/2/182 fatcat:3lqywvqtlvhnpg2puw7squg4re