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Table 1

Gravitational scaling relations.

Property Proportionality Scaling for var. Δ r-dependencea Scaling for fixed Δ Deviation

radius, RΔ  ∝ M1/3   F−2/3  ∝ T1/2   F-1  ∝ r T1/2   E-1
density profilea ρ ∝ MR-3  ∝ F(z)2  ∝ r-2  ∝ E(z)2  −
luminosityb LX ∝ ρ2   R3     ∝ T1.5   F  ∝ r1/2  ∝  39%
bolom. lum. Lbol ∝ ρ2   R3   T1/2  ∝ T2   F  ∝ r1/2  ∝  39%
entropy, K  ∝ T/ρ2/3  ∝ T   F−4/3  ∝ r  ∝ TXE−4/3Δ(z)−1/6 7.5%
gas mass  ∝ ρR3  ∝ T3/2   F-1  ∝ r  −
YX  ∝ R3  ∝ T5/2   F-1  ∝ r  −
pressure  ∝   ∝ T   F2  ∝ r−7/3  ∝ TXE2Δ(z)−1/6 7.5%
surf. bright.a SX ∝ ρ2   R  ∝ T1/2   F3  ∝ r-3  ∝   −

temperature TX  ∝ M2/3   F2/3 (M(r) ∝ r)  ∝   −
luminosityb L X  ∝ M   F2  ∝ M  E2   Δ(z)3/4 39%
bolom. lum. Lbol  ∝ M4/3   F7/3  ∝  39%
entropy K  ∝ M2/3   F−2/3  ∝  7.5%
gas mass Mgas  ∝ M  ∝ M  −
YX YX  ∝ M5/3   F2/3  ∝   −
pressure P  ∝ M2/3   F8/3  ∝  7.5%
surf. bright.a SX  ∝ M1/3   F10/3  ∝   −

Notes. Columns 1 and 2 give the property and its definition, and Col. 3 provides the scaling relation where the parameter F(z) can be read in two ways: (i) for recent formation approximation F(z) ≡ E(z) × Δ(z)1/2 and for the fixed overdensity model F = E(z). Column 4 gives the assumed radial dependence of the property of Col. 1, and Col. 5 the scaling relation for the case that the property of Col. 1 is taken at a fixed overdensity radius. The temperature TX is in all cases defined as a mean measured temperature. Entropy, K, pressure, surface brightness are local values at the fiducial radius. Luminosity, gas mass, and YX are integral parameters. M   is the mass at fixed overdensity. Column 6 lists the deviation of the scaling relation if the Δ(z) term is neglected for a comparison of clusters at z = 0 and z = 1.

(a)

Columns 4 to 6 refer to the radial dependence of the profile in the radial range r ~ r500 to r1000. Here we assume ρ ∝ r-2, a β-model for the gas with β = 2/3 and K ∝ r which implies T ∝ r − 1/3.

(b)

Assuming a temperature independent emissivity for the luminosity in a restricted soft X-ray band that is justified for TX > 2 keV (see text).

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