Mass profile decomposition of the Frontier Fields cluster MACS J0416-02403. Insights on the Dark-Matter inner profile

Understand

We present a high resolution dissection of the two-dimensional total mass distribution in the core of the Hubble Frontier Fields galaxy cluster MACS J0416.1-2403, at z ~ 0.396.

• We exploit HST/WFC3 near-IR (F160W) imaging, VLT/MUSE spectroscopy, and Chandra data to separate the stellar, hot gas, and dark-matter mass components in the inner 300 kpc of the cluster.
• We combine the recent results of our refined strong lensing analysis, which includes the contribution of the intracluster gas, with the modeling of the surface brightness and stellar mass distributions of 193 cluster members, of which 144 are spectroscopically confirmed.
• We find that moving from 10 to 300 kpc from the cluster center the stellar to total mass fraction decreases from 12% to 1% and the hot gas to total mass fraction increases from 3% to 9%, resulting in a baryon fraction of approximately 10% at the outermost radius.