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| -rw-r--r-- | fg21sim/extragalactic/clusters/helper.py | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/fg21sim/extragalactic/clusters/helper.py b/fg21sim/extragalactic/clusters/helper.py index c4b3d72..18e7133 100644 --- a/fg21sim/extragalactic/clusters/helper.py +++ b/fg21sim/extragalactic/clusters/helper.py @@ -30,6 +30,10 @@ References Lokas & Mamon 2001, MNRAS, 321, 155 http://adsabs.harvard.edu/abs/2001MNRAS.321..155L +.. [miniati2015] + Miniati & Beresnyak 2015, Nature, 523, 59 + http://adsabs.harvard.edu/abs/2015Natur.523...59M + .. [murgia2009] Murgia et al. 2009, A&A, 499, 679 http://adsabs.harvard.edu/abs/2009A%26A...499..679M @@ -373,6 +377,28 @@ def magnetic_field( return B +def plasma_beta( + mass, + z=0.0, + eta_b=CONFIGS.getn("extragalactic/clusters/eta_b"), + kT_out=CONFIGS.getn("extragalactic/clusters/kT_out"), + ): + """ + Calculate the β value of the ICM, which is defined as: + β ≡ P_gas / u_B + where "P_gas" is the gas pressue: P_gas = n_th * kT; + "u_B" is the magnetic field energy density: u_B = B² / 8π . + + Reference: Ref.[miniati2015],Eq.(2) + """ + n_th = density_number_thermal(mass, z) # [cm^-3] + kT = kT_cluster(mass, z, kT_out=kT_out) * AUC.keV2erg # [erg] + P = n_th * kT + B = magnetic_field(mass, z, eta_b=eta_b, kT_out=kT_out) * 1e-6 # [G] + beta = 8*np.pi * P / B**2 + return beta + + def speed_sound(kT): """ The adiabatic sound speed in cluster ICM. |