Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published February 10, 2015 | Published + Submitted
Journal Article Open

CLASH-VLT: Insights on the Mass Substructures in the Frontier Fields Cluster MACS J0416.1–2403 through Accurate Strong Lens Modeling


We present a detailed mass reconstruction and a novel study on the substructure properties in the core of the Cluster Lensing And Supernova survey with Hubble (CLASH) and Frontier Fields galaxy cluster MACS J0416.1–2403. We show and employ our extensive spectroscopic data set taken with the VIsible Multi-Object Spectrograph instrument as part of our CLASH-VLT program, to confirm spectroscopically 10 strong lensing systems and to select a sample of 175 plausible cluster members to a limiting stellar mass of log (M_*/M_☉) ≃ 8.6. We reproduce the measured positions of a set of 30 multiple images with a remarkable median offset of only 0."3 by means of a comprehensive strong lensing model comprised of two cluster dark-matter halos, represented by cored elliptical pseudo-isothermal mass distributions, and the cluster member components, parameterized with dual pseudo-isothermal total mass profiles. The latter have total mass-to-light ratios increasing with the galaxy HST/WFC3 near-IR (F160W) luminosities. The measurement of the total enclosed mass within the Einstein radius is accurate to ~5%, including the systematic uncertainties estimated from six distinct mass models. We emphasize that the use of multiple-image systems with spectroscopic redshifts and knowledge of cluster membership based on extensive spectroscopic information is key to constructing robust high-resolution mass maps. We also produce magnification maps over the central area that is covered with HST observations. We investigate the galaxy contribution, both in terms of total and stellar mass, to the total mass budget of the cluster. When compared with the outcomes of cosmological N-body simulations, our results point to a lack of massive subhalos in the inner regions of simulated clusters with total masses similar to that of MACS J0416.1–2403. Our findings of the location and shape of the cluster dark-matter halo density profiles and on the cluster substructures provide intriguing tests of the assumed collisionless, cold nature of dark matter and of the role played by baryons in the process of structure formation.

Additional Information

© 2015 American Astronomical Society. Received 2014 July 28; accepted 2014 December 9; published 2015 February 6. We thank the ESO User Support group, and specifically Vincenzo Mainieri, for the continuous and excellent support on the implementation of the Large Programme 186.A-0798. The CLASH Multi-Cycle Treasury Program is based on observations made with the NASA/ESA Hubble Space Telescope. The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. ACS was developed under NASA Contract NAS 5-32864. This research is supported in part by NASA Grant HST-GO-12065.01-A. The Dark Cosmology Centre is funded by the DNRF. We acknowledge partial support by the DFG Cluster of Excellence Origin Structure of the Universe. G.B.C. is supported by the CAPES-ICRANET program through the grant BEX 13946/13-7. We acknowledge financial support from MIUR PRIN2010-2011 (J91J12000450001). K.U. acknowledges support from the National Science Council of Taiwan (grant NSC100-2112-M-001-008-MY3). Support for A.Z. is provided by NASA through Hubble Fellowship grant HST-HF-51334.01-A awarded by STScI. V.P. acknowledges a grant from "Consorzio per la Fisica - Trieste." A.F. acknowledges the support by INAF PRIN 2010 grant (VIPERS).

Attached Files

Published - 0004-637X_800_1_38.pdf

Submitted - 1407.7866v2.pdf


Files (6.8 MB)
Name Size Download all
4.9 MB Preview Download
1.9 MB Preview Download

Additional details

August 22, 2023
August 22, 2023