The peculiar cluster MACS J0417.5-1154 in the C and X-bands

Abstract

We present 5.5 and 9.0 GHz Australia Telescope Compact Array (ATCA) observations of the cluster MACSJ0417.5−1154, one of the most massive galaxy clusters and one of the brightest in X-ray in the Massive Cluster Survey (MACS). We estimate diffuse emission at 5.5 and 9.0 GHz from our ATCA observations, and compare the results with the 235 MHz and 610 MHz GMRT observations and 1575 MHz VLA observations. We also estimate the diffuse emission at low frequencies from existing GLEAM survey data (using the MWA telescope 1 ), and find that the steepening reported in earlier studies may have been an artefact of underestimates of diffuse emission at low frequencies.High-frequency radio observations of galaxy cluster mergers therefore provide an important complement to low-frequency observations, not only for a probing the 'on' and 'off' state of radio halos in these mergers, but also to constrain energetics of cluster mergers. We comment on the future directions that further studies of this cluster can take.

RELICS: Strong Lensing Analysis of MACS J0417.5–1154 and Predictions for Observing the Magnified High-redshift Universe with JWST

“…The top red cross shows the position of the center of the bridge potential. The red arrow indicates the shifted location of the main DM halo located at the red cross.The contour at 1.5 × 10 9 M kpc −2 guides the eye to the apparent comet-like profile as seen in the X-ray luminosity distribution reported by previous studies(Ebeling et al 2014;Parekh et al 2017;Sandhu et al 2018). A direct comparison between the DM and X-ray light distributions is shown and discussed inJauzac et al (2019).…”

“…Based on Chandra X-ray observations, Mann & Ebeling (2012) report that the peak of the X-ray emission is centered on the primary brightest cluster galaxy (BCG) with a slight diffuse emission extended toward the second brightest galaxy in the cluster core. Dwarakanath et al (2011), Parekh et al (2017), and Sandhu et al (2018) confirm this feature in the radio. Parekh et al (2017) highlight the similarity in morphology to the clusters Abell 2746 and 1E 0657−56 (the "Bullet cluster"), strengthening the hypothesis made by Mann & Ebeling (2012) that MACS J0417 is a recent merger, probably oriented along the line of sight, or alternatively, caught close to a turnaround.…”

The core of the massive cluster merger MACS J0417.5−1154 as seen by VLT/MUSE

“…The Brightest Cluster Galaxy (BCG) of MACS J0417 shows strong optical emission lines and atypical photometric colours, consistent with a classification of 'active' in the framework advanced by Green et al (2016), reinforcing the status F1 64.3895834 -11.9112644 0.3471 F2 64.3900500 -11.9118044 0.2307 of MACS J0417 as a dynamically evolving galaxy cluster. At radio wavelengths, MACS J0417 was found to host a peculiar radio halo first discussed in Dwarakanath et al (2011), and more recently in Parekh et al (2017) and Sandhu et al (2018). The radio diffuse emission is extended along the North-West direction, sign of a high velocity merger.…”