Temperature and entropy profiles to the virial radius of the Abell 1246 cluster observed with Suzaku

We report properties of the intracluster medium (ICM) in Abell1246 to the virial radius (r200) and further outside as observed with Suzaku. The ICM emission is clearly detected to r200, and we derive profiles of electron temperature, density, entropy, and cluster mass based on the spectral analysis. The temperature shows variation from ∼7keV at the central region to ∼2.5keV around r200. The total mass in r500 is (4.3 ±0.4) ×10 14 M� , assuming hydrostatic equilibrium. At r >r500, the hydrostatic mass starts to decline and we therefore employ the total mass within r200 based on a weak-lens mass profile obtained from a sample of lower-mass clusters. This yields a gas mass fraction atr200 consistent with the cosmic baryon fraction, i.e., ∼17%. The entropy profile indicates a flatter slope than that of the numerical simulation, particularly in r >r500. These tendencies are similar to those of other clusters observed with Suzaku. We detect no significant ICM emissionoutsideofr200,and2σ upperlimitsofredshiftedO VIIandO VIIIlineintensitiesare constrained to be less than 2.9 and 5.6 ×10 −7 photonscm −2 s −1 arcmin −2 , respectively. The O VII line upper limit indicates nH <4.7 ×10 −5 cm −3 (Z/0.2Z� ) −1/2 (L/20Mpc) −1/2 , which corresponds to an overdensity, δ< 160 (Z/0.2Z� ) −1/2 (L/20Mpc) −1/2 .