Cooling rate and turbulence in the intracluster medium of the cool-core cluster Abell 2667
Simulation of an Abell 2667 observation with NewAthena / X-IFU. The black dots are data points, and the red line is the best-fit isothermal model combined with an isobaric cooling flow model in three temperature bins (0.5–1, 1–2, and 2–3 keV).
By Marika Lepore
We present a detailed analysis of the thermal X-ray emission from the intracluster medium (ICM) in the cool-core galaxy cluster Abell 2667 (z = 0.23). Using deep XMM-Newton EPIC and RGS data, combined with archival Chandra observations, we searched for low-temperature (<2 keV) gas linked to cooling flows that fuel star formation and black hole feeding. Our analysis sets 1σ upper limits on the gas cooling rate of ~40 M☉/yr (0.5–1 keV) and ~50–60 M☉/yr (1–2 keV). We detect turbulent broadening with a 1σ upper limit of ~320 km/s, higher than in similar clusters, suggesting the presence of some mechanisms boosting significant turbulence in the atmosphere of Abell 2667. Chandra imaging suggests the presence of a possible cold front linked to sloshing or ICM cavities, but the dominant physical mechanism responsible for turbulence remains unclear. These results indicate that Abell 2667 is similar to other low-redshift cool-core clusters, with limited evidence of recent feedback events. However, the large upper limit on turbulent velocity suggests ongoing ICM heating that may suppress cooling while contributing to future condensation cycles.
Future NewAthena observations of this cluster will offer unprecedented insights. They will provide a spectacular line-rich spectrum, enabling velocity broadening measurements with a 1σ uncertainty of ~6 km/s, a substantial improvement over current constraints. Cooling rate estimates will also achieve tighter precision, with ~10–20% uncertainties (0.5–1 keV) on a mass deposition rate (MDR) of 10 M☉/yr. Additionally, NewAthena will constrain the truncation temperature of cooling gas with a 1σ error of 4% and the MDR with 8% uncertainty. In conclusion, Athena will allow us to investigate the cooling and heating mechanisms in Abell 2667, providing definitive constraints on the scenarios outlined in our work.