skip to main content


Title: Quantifying substructures in Hubble Frontier Field clusters: comparison with ΛCDM simulations

The Hubble Frontier Fields (HFF) are six clusters of galaxies, all showing indications of recent mergers, which have recently been observed for lensed images. As such they are the natural laboratories to study the merging history of galaxy clusters. In this work, we explore the 2D power spectrum of the mass distribution $$P_{\rm M}(k)$$ as a measure of substructure. We compare $$P_{\rm M}(k)$$ of these clusters (obtained using strong gravitational lensing) to that of $$\Lambda$$CDM simulated clusters of similar mass. In order to compute lensing $$P_{\rm M}(k)$$, we produced free-form lensing mass reconstructions of HFF clusters, without any light traces mass (LTM) assumption. Moreover, the inferred power at small scales tends to be larger if (i)~the cluster is at lower redshift, and/or (ii)~there are deeper observations and hence more lensed images. In contrast, lens reconstructions assuming LTM show higher power at small scales even with fewer lensed images; it appears the small scale power in the LTM reconstructions is dominated by light information, rather than the lensing data. The average lensing derived $$P_{\rm M}(k)$$ shows lower power at small scales as compared to that of simulated clusters at redshift zero, both dark-matter only and hydrodynamical. The possible reasons are: (i)~the available strong lensing data are limited in their effective spatial resolution on the mass distribution, (ii)~HFF clusters have yet to build the small scale power they would have at $$z\sim 0$$, or (iii)~simulations are somehow overestimating the small scale power.
 [1] ;  [2] ;  [3] ;  [4] ;  [3]
  1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Zurich (Switzerland)
  2. Univ. of Zurich (Switzerland)
  3. Univ. of Minnesota, Minneapolis, MN (United States)
  4. Univ. of Hasselt (Belgium)
Publication Date:
Report Number(s):
FERMILAB-PUB-16-083-A; arXiv:1507.01532
Journal ID: ISSN 0035-8711; 1381500
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 459; Journal Issue: 2; Journal ID: ISSN 0035-8711
Royal Astronomical Society
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; galaxies: clusters: individual: Abell 2744; galaxies: clusters: individual: Abell 370; galaxies: clusters: individual: Abell S1063; galaxies: clusters: individual: MACS J0416.1+2403; galaxies: clusters: individual: MACS J0717.5+3745; galaxies: clusters: individual: MACS J1149.5+2223
OSTI Identifier: