From a5aa0b4e4c270c84aa4347c9789332b75d661a11 Mon Sep 17 00:00:00 2001
From: Aaron LI <aly@aaronly.me>
Date: Sat, 26 Jan 2019 16:52:52 +0800
Subject: clusters/halo: Move and rename _velocity_turb() to _velocity_turb()
---
fg21sim/extragalactic/clusters/halo.py | 114 ++++++++++++++++-----------------
1 file changed, 57 insertions(+), 57 deletions(-)
(limited to 'fg21sim')
diff --git a/fg21sim/extragalactic/clusters/halo.py b/fg21sim/extragalactic/clusters/halo.py
index 669f46e..14a9028 100644
--- a/fg21sim/extragalactic/clusters/halo.py
+++ b/fg21sim/extragalactic/clusters/halo.py
@@ -218,6 +218,61 @@ class RadioHalo1M:
uconv = AUC.kpc2km * AUC.s2Gyr # [kpc]/[km/s] => [Gyr]
return uconv * 2*L_turb / vi # [Gyr]
+ @lru_cache()
+ def velocity_turb(self, t_merger):
+ """
+ Calculate the turbulence velocity dispersion.
+
+ NOTE
+ ----
+ During the merger, a fraction of the merger kinetic energy is
+ transferred into the turbulence within the region of radius R_turb.
+ Then estimate the turbulence velocity dispersion from its energy.
+
+ Merger energy:
+ E_merger ≅ <ρ_gas> * v_i^2 * V_turb
+ V_turb = ᴨ * r_s^2 * (R_vir+r_s)
+ Turbulence energy:
+ E_turb ≅ η_turb * E_merger ≅ 0.5 * M_turb * <v_turb^2>
+ => Velocity dispersion:
+ <v_turb^2> ≅ 2*η_turb * <ρ_gas> * v_i^2 * V_turb / M_turb
+ M_turb = int_0^R_turb[ ρ_gas(r)*4ᴨ*r^2 ]dr
+ where:
+ <ρ_gas>: mean gas density of the main cluster
+ R_vir: virial radius of the main cluster
+ R_turb: radius of turbulence region
+ v_i: impact velocity
+ r_s: stripping radius of the in-falling sub-cluster
+
+ Returns
+ -------
+ v_turb : float
+ The turbulence velocity dispersion
+ Unit: [km/s]
+ """
+ self._validate_t_merger(t_merger)
+ z = COSMO.redshift(t_merger)
+ M_main = self.mass_main(t_merger)
+ M_sub = self.mass_sub(t_merger)
+ r_s = self.radius_stripping(t_merger) # [kpc]
+ R_turb = self.radius_turbulence(t_merger) # [kpc]
+
+ rho_gas_f = helper.calc_gas_density_profile(
+ M_main, z, f_rc=self.f_rc, beta=self.beta)
+ M_turb = 4*np.pi * integrate.quad(
+ lambda r: rho_gas_f(r) * r**2,
+ a=0, b=R_turb)[0] # [Msun]
+
+ v_i = helper.velocity_impact(M_main, M_sub, z) # [km/s]
+ rho_main = helper.density_number_thermal(M_main, z) # [cm^-3]
+ rho_main *= AC.mu*AC.u * AUC.g2Msun * AUC.kpc2cm**3 # [Msun/kpc^3]
+ R_vir = helper.radius_virial(M_main, z) # [kpc]
+
+ V_turb = np.pi * r_s**2 * R_vir # [kpc^3]
+ E_turb = self.eta_turb * rho_main * v_i**2 * V_turb
+ v2_turb = 2 * E_turb / M_turb # [km^2/s^2]
+ return np.sqrt(v2_turb) # [km/s]
+
@lru_cache()
def mach_turb(self, t_merger):
"""
@@ -225,7 +280,7 @@ class RadioHalo1M:
"""
self._validate_t_merger(t_merger)
cs = helper.speed_sound(self.kT(t_merger)) # [km/s]
- v_turb = self._velocity_turb(t_merger) # [km/s]
+ v_turb = self.velocity_turb(t_merger) # [km/s]
return v_turb / cs
@lru_cache()
@@ -302,7 +357,7 @@ class RadioHalo1M:
L = 2 * self.radius_turbulence(t_merger) # [kpc]
k_L = 2 * np.pi / L_turb
cs = helper.speed_sound(self.kT(t_merger)) # [km/s]
- v_t = self._velocity_turb(t_merger) # [km/s]
+ 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]
@@ -623,61 +678,6 @@ class RadioHalo1M:
return helper.magnetic_field(mass=mass, z=z,
eta_b=eta_b, kT_out=kT_out)
- @lru_cache()
- def _velocity_turb(self, t_merger):
- """
- Calculate the turbulence velocity dispersion.
-
- NOTE
- ----
- During the merger, a fraction of the merger kinetic energy is
- transferred into the turbulence within the region of radius R_turb.
- Then estimate the turbulence velocity dispersion from its energy.
-
- Merger energy:
- E_merger ≅ <ρ_gas> * v_i^2 * V_turb
- V_turb = ᴨ * r_s^2 * (R_vir+r_s)
- Turbulence energy:
- E_turb ≅ η_turb * E_merger ≅ 0.5 * M_turb * <v_turb^2>
- => Velocity dispersion:
- <v_turb^2> ≅ 2*η_turb * <ρ_gas> * v_i^2 * V_turb / M_turb
- M_turb = int_0^R_turb[ ρ_gas(r)*4ᴨ*r^2 ]dr
- where:
- <ρ_gas>: mean gas density of the main cluster
- R_vir: virial radius of the main cluster
- R_turb: radius of turbulence region
- v_i: impact velocity
- r_s: stripping radius of the in-falling sub-cluster
-
- Returns
- -------
- v_turb : float
- The turbulence velocity dispersion
- Unit: [km/s]
- """
- self._validate_t_merger(t_merger)
- z = COSMO.redshift(t_merger)
- M_main = self.mass_main(t_merger)
- M_sub = self.mass_sub(t_merger)
- r_s = self.radius_stripping(t_merger) # [kpc]
- R_turb = self.radius_turbulence(t_merger) # [kpc]
-
- rho_gas_f = helper.calc_gas_density_profile(
- M_main, z, f_rc=self.f_rc, beta=self.beta)
- M_turb = 4*np.pi * integrate.quad(
- lambda r: rho_gas_f(r) * r**2,
- a=0, b=R_turb)[0] # [Msun]
-
- v_i = helper.velocity_impact(M_main, M_sub, z) # [km/s]
- rho_main = helper.density_number_thermal(M_main, z) # [cm^-3]
- rho_main *= AC.mu*AC.u * AUC.g2Msun * AUC.kpc2cm**3 # [Msun/kpc^3]
- R_vir = helper.radius_virial(M_main, z) # [kpc]
-
- V_turb = np.pi * r_s**2 * (R_vir+r_s) # [kpc^3]
- E_turb = self.eta_turb * rho_main * v_i**2 * V_turb
- v2_turb = 2 * E_turb / M_turb # [km^2/s^2]
- return np.sqrt(v2_turb) # [km/s]
-
def _is_turb_active(self, t):
"""
Is the turbulence acceleration is active at the given time?
--
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