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authorAaron LI <aly@aaronly.me>2018-01-05 15:48:58 +0800
committerAaron LI <aly@aaronly.me>2018-01-05 15:48:58 +0800
commit3748c60b5d80db25f713d3906a2c0106368a09ac (patch)
treee32975b8fb67716347542384a3f5b796015c28cc /fg21sim/extragalactic
parent3508da9c0d3cd179c84e193c632df732a6ab6404 (diff)
downloadfg21sim-3748c60b5d80db25f713d3906a2c0106368a09ac.tar.bz2
clusters/halo: update turbulence acceleration calc. with _merger_time()
Diffstat (limited to 'fg21sim/extragalactic')
-rw-r--r--fg21sim/extragalactic/clusters/halo.py48
1 files changed, 20 insertions, 28 deletions
diff --git a/fg21sim/extragalactic/clusters/halo.py b/fg21sim/extragalactic/clusters/halo.py
index 1f9e6b2..f9e9eb0 100644
--- a/fg21sim/extragalactic/clusters/halo.py
+++ b/fg21sim/extragalactic/clusters/halo.py
@@ -193,9 +193,7 @@ class RadioHalo:
"""
return self.age_merger
- @property
- @lru_cache()
- def time_turbulence(self):
+ def time_turbulence(self, t=None):
"""
The time duration the merger-induced turbulence persists, which
is used to approximate the effective turbulence acceleration
@@ -203,16 +201,20 @@ class RadioHalo:
Unit: [Gyr]
"""
- return helper.time_turbulence(self.M_main, self.M_sub,
- z=self.z_merger, configs=self.configs)
+ t_merger = self._merger_time(t)
+ mass_main = self.mass_main(t=t_merger)
+ mass_sub = self.mass_sub(t=t_merger)
+ z_merger = COSMO.redshift(t_merger)
+ return helper.time_turbulence(mass_main, mass_sub, z=z_merger,
+ configs=self.configs)
- @property
- def mach_turbulence(self):
+ def mach_turbulence(self, t=None):
"""
The turbulence Mach number determined from its velocity dispersion.
"""
- cs = helper.speed_sound(self.kT_main()) # [km/s]
- v_turb = self._velocity_turb() # [km/s]
+ t_merger = self._merger_time(t)
+ cs = helper.speed_sound(self.kT(t_merger)) # [km/s]
+ v_turb = self._velocity_turb(t_merger) # [km/s]
return v_turb / cs
@property
@@ -272,7 +274,7 @@ class RadioHalo:
return helper.kT_cluster(self.M_obs, z=self.z_obs,
configs=self.configs)
- def kT_main(self, t=None):
+ def kT(self, t=None):
"""
The ICM mean temperature of the main cluster at cosmic time
``t`` (default: ``self.age_begin``).
@@ -285,7 +287,7 @@ class RadioHalo:
z = COSMO.redshift(t)
return helper.kT_cluster(mass=mass, z=z, configs=self.configs)
- def tau_acceleration(self, t=None):
+ def tau_acceleration(self, t):
"""
Calculate the electron acceleration timescale due to turbulent
waves, which describes the turbulent acceleration efficiency.
@@ -308,19 +310,11 @@ class RadioHalo:
τ_acc = p^2 / (4*D_pp)
= (η_e * c_s^3 * L) / (16π * ζ * <v_turb^2>^2)
- NOTE
- ----
- Considering that the turbulence acceleration is a 2nd-order Fermi
- process, it has only an effective acceleration time ~<1 Gyr.
- Therefore, only during the period that strong turbulence persists
- in the ICM that the turbulence could effectively accelerate the
- relativistic electrons.
-
Parameters
----------
t : float, optional
The cosmic time when to determine the acceleration timescale.
- Default: ``self.age_obs``
+ Unit: [Gyr]
Returns
-------
@@ -334,15 +328,13 @@ class RadioHalo:
* Ref.[pinzke2017],Eq.(37)
* Ref.[miniati2015],Eq.(29)
"""
- if t is None:
- t = self.age_begin
- if t > self.age_begin + self.time_turbulence:
- return np.inf
-
- R_vir = helper.radius_virial(mass=self.M_main, z=self.z_merger)
+ t_merger = self._merger_time(t)
+ z_merger = COSMO.redshift(t_merger)
+ mass_main = self.mass_main(t_merger)
+ R_vir = helper.radius_virial(mass=mass_main, z=z_merger)
L = self.f_lturb * R_vir # [kpc]
- cs = helper.speed_sound(self.kT_main()) # [km/s]
- v_turb = self._velocity_turb() # [km/s]
+ cs = helper.speed_sound(self.kT(t_merger)) # [km/s]
+ v_turb = self._velocity_turb(t_merger) # [km/s]
tau = (self.x_cr * cs**3 * L /
(16*np.pi * self.zeta_ins * v_turb**4)) # [s kpc/km]
tau *= AUC.s2Gyr * AUC.kpc2km # [Gyr]