Key points are not available for this paper at this time.
We present results from Suzaku Key Project observations of the Virgo Cluster, the nearest galaxy cluster to us, mapping its X-ray properties along four long 'arms' extending beyond the virial radius. The entropy profiles along all four azimuths increase with radius, then level out beyond 0.5r 200 , while the average pressure at large radii exceeds Planck Sunyaev-Zel'dovich measurements. These results can be explained by enhanced gas density fluctuations (clumping) in the cluster's outskirts. Using a standard Navarro, Frenk and White model, we estimate a virial mass, radius and concentration parameter of M 200 = 1.05 0.02 10 14 M , r 200 = 974.1 5.7 kpc and c = 8.8 0.2, respectively. The inferred cumulative baryon fraction exceeds the cosmic mean at r r 200 along the major axis, suggesting enhanced gas clumping possibly sourced by a candidate large-scale structure filament along the north-south direction. The Suzaku data reveal a large-scale sloshing pattern, with two new cold fronts detected at radii of 233 and 280 kpc along the western and southern arms, respectively. Two high-temperature regions are also identified 1 Mpc towards the south and 605 kpc towards the west of M87, likely representing shocks associated with the ongoing cluster growth. Although systematic uncertainties in measuring the metallicity for low-temperature plasma remain, the data at large radii appear consistent with a uniform metal distribution on scales of 90 180 kpc and larger, providing additional support for the early chemical enrichment scenario driven by galactic winds at redshifts of 2-3.
Simionescu et al. (Fri,) studied this question.