From 2ad2169909838a6a8055fc69541a1cde8ffe8391 Mon Sep 17 00:00:00 2001 From: Aaron LI Date: Fri, 25 Jan 2019 16:17:23 +0800 Subject: clusters/halo: Account for mass scaling in tau_acceleration() Add configuration option "mass_index" to specify the scaling index. --- fg21sim/extragalactic/clusters/halo.py | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'fg21sim/extragalactic') diff --git a/fg21sim/extragalactic/clusters/halo.py b/fg21sim/extragalactic/clusters/halo.py index 4e87f3f..56c8622 100644 --- a/fg21sim/extragalactic/clusters/halo.py +++ b/fg21sim/extragalactic/clusters/halo.py @@ -154,6 +154,7 @@ class RadioHalo1M: self.eta_turb = configs.getn(comp+"/eta_turb") self.eta_e = configs.getn(comp+"/eta_e") self.x_cr = configs.getn(comp+"/x_cr") + self.mass_index = configs.getn(comp+"/mass_index") self.gamma_min = configs.getn(comp+"/gamma_min") self.gamma_max = configs.getn(comp+"/gamma_max") self.gamma_np = configs.getn(comp+"/gamma_np") @@ -293,6 +294,18 @@ class RadioHalo1M: τ'_acc = γ^2 / (4 * D'_γγ) = X_cr * c_s^3 / (8 * ζ * k_L * v_t^4) + Previous studies show that more massive clusters are more efficient + to accelerate electrons to be radio bright. To further account for + this scaling relation: + D_γγ = D'_γγ * f_m * (M_main / 1e15)^m + where: + m: scaling index + f_m: normalization + Therefore, the final acceleration timescale is: + τ_acc = τ'_acc * (M_main / 1e15)^(-m) / f_m + = X_cr * c_s^3 * (M_main/1e15)^(-m) / (8*f_acc * k_L * v_t^4) + with: f_acc = f_m * ζ + WARNING ------- Tests show that a very large acceleration timescale (e.g., @@ -335,6 +348,11 @@ class RadioHalo1M: v_t = self._velocity_turb(t_merger) # [km/s] tau = self.x_cr * cs**3 / (8*k_L * v_t**4) tau *= AUC.s2Gyr * AUC.kpc2km # [s kpc/km] -> [Gyr] + + # Mass scaling + M_main = self.mass_main(t) + f_mass = (M_main / 1e15) ** (-self.mass_index) + tau *= f_mass tau /= self.f_acc # tune factor (folded with "zeta_ins") # Impose the maximum acceleration timescale -- cgit v1.2.2