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authorAaron LI <aly@aaronly.me>2018-01-04 21:40:28 +0800
committerAaron LI <aly@aaronly.me>2018-01-04 21:49:55 +0800
commit7473c9374f31f4f8fc10d47c3ed7c85689b1be05 (patch)
tree5be72e443e484db3f14d6b9439469274e4e49054 /fg21sim
parent68bc85f371d9ba258b8d9e970e1efaeda87d0122 (diff)
downloadfg21sim-7473c9374f31f4f8fc10d47c3ed7c85689b1be05.tar.bz2
clusters/halo: small updates and some cleanups
Diffstat (limited to 'fg21sim')
-rw-r--r--fg21sim/extragalactic/clusters/halo.py93
-rw-r--r--fg21sim/extragalactic/clusters/main.py12
2 files changed, 45 insertions, 60 deletions
diff --git a/fg21sim/extragalactic/clusters/halo.py b/fg21sim/extragalactic/clusters/halo.py
index 5c7eb5b..365aeda 100644
--- a/fg21sim/extragalactic/clusters/halo.py
+++ b/fg21sim/extragalactic/clusters/halo.py
@@ -138,9 +138,11 @@ class RadioHalo:
configs=CONFIGS):
self.M_obs = M_obs
self.z_obs = z_obs
+ self.age_obs = COSMO.age(z_obs)
self.M_main = M_main
self.M_sub = M_sub
self.z_merger = z_merger
+ self.age_merger = COSMO.age(z_merger)
self._set_configs(configs)
self._set_solver()
@@ -184,24 +186,12 @@ class RadioHalo:
return self.fpsolver.x
@property
- def age_obs(self):
- return COSMO.age(self.z_obs)
-
- @property
def age_begin(self):
"""
The cosmic time when the merger begins.
Unit: [Gyr]
"""
- return COSMO.age(self.z_merger)
-
- @property
- def tback_merger(self):
- """
- The time from the observation (``z_obs``) back to the beginning
- of the merger (``z_merger``).
- """
- return (self.age_obs - self.age_begin) # [Gyr]
+ return self.age_merger
@property
@lru_cache()
@@ -221,7 +211,7 @@ class RadioHalo:
"""
The turbulence Mach number determined from its velocity dispersion.
"""
- cs = helper.speed_sound(self.kT_main) # [km/s]
+ cs = helper.speed_sound(self.kT_main()) # [km/s]
v_turb = self._velocity_turb() # [km/s]
return v_turb / cs
@@ -236,7 +226,6 @@ class RadioHalo:
return helper.radius_virial(mass=self.M_obs, z=self.z_obs)
@property
- @lru_cache()
def radius(self):
"""
The estimated radius for the simulated radio halo.
@@ -248,7 +237,6 @@ class RadioHalo:
def angular_radius(self):
"""
The angular radius of the radio halo.
-
Unit: [arcsec]
"""
DA = COSMO.DA(self.z_obs) * 1e3 # [Mpc] -> [kpc]
@@ -259,13 +247,11 @@ class RadioHalo:
def volume(self):
"""
The halo volume, calculated from the above radius.
-
Unit: [kpc^3]
"""
return (4*np.pi/3) * self.radius**3
@property
- @lru_cache()
def B_obs(self):
"""
The magnetic field strength at the simulated observation
@@ -278,7 +264,6 @@ class RadioHalo:
configs=self.configs)
@property
- @lru_cache()
def kT_obs(self):
"""
The ICM mean temperature of the cluster at ``z_obs``.
@@ -287,17 +272,18 @@ class RadioHalo:
return helper.kT_cluster(self.M_obs, z=self.z_obs,
configs=self.configs)
- @property
- @lru_cache()
- def kT_main(self):
+ def kT_main(self, t=None):
"""
- The mean temperature of the main cluster ICM at ``z_merger``
- when the merger begins.
+ The ICM mean temperature of the main cluster at cosmic time
+ ``t`` (default: ``self.age_begin``).
Unit: [keV]
"""
- return helper.kT_cluster(mass=self.M_main, z=self.z_merger,
- configs=self.configs)
+ if t is None:
+ t = self.age_begin
+ mass = self.mass_main(t=t)
+ z = COSMO.redshift(t)
+ return helper.kT_cluster(mass=mass, z=z, configs=self.configs)
@property
@lru_cache()
@@ -333,7 +319,7 @@ class RadioHalo:
"""
R_vir = helper.radius_virial(mass=self.M_main, z=self.z_merger)
L = self.f_lturb * R_vir # [kpc]
- cs = helper.speed_sound(self.kT_main) # [km/s]
+ cs = helper.speed_sound(self.kT_main()) # [km/s]
v_turb = self._velocity_turb() # [km/s]
tau = (self.x_cr * cs**3 * L /
(16*np.pi * self.zeta_ins * v_turb**4)) # [s kpc/km]
@@ -600,7 +586,14 @@ class RadioHalo:
(self.fp_diffusion(gamma, t) * 2 / gamma))
return advection
- def _mass(self, t):
+ def mass_merged(self, t=None):
+ """
+ The mass of the merged cluster.
+ Unit: [Msun]
+ """
+ return self.M_main + self.M_sub
+
+ def mass_main(self, t):
"""
Calculate the main cluster mass at the given (cosmic) time.
@@ -628,6 +621,22 @@ class RadioHalo:
mass = rate * (t - t0) + self.M_main
return mass
+ def magnetic_field(self, t):
+ """
+ Calculate the mean magnetic field strength of the main cluster mass
+ at the given (cosmic) time.
+
+ Returns
+ -------
+ B : float
+ The mean magnetic field strength of the main cluster.
+ Unit: [uG]
+ """
+ z = COSMO.redshift(t)
+ mass = self.mass_main(t) # [Msun]
+ B = helper.magnetic_field(mass=mass, z=z, configs=self.configs)
+ return B
+
def _velocity_turb(self, t=None):
"""
Calculate the turbulence velocity dispersion (i.e., turbulence
@@ -661,35 +670,13 @@ class RadioHalo:
if t is None:
t = self.age_begin
z = COSMO.redshift(t)
- mass = self.M_main + self.M_sub
+ mass = self.mass_merged(t)
R_vir = helper.radius_virial(mass=mass, z=z) * AUC.kpc2cm # [cm]
v2_vir = (AC.G * self.M_main*AUC.Msun2g / R_vir) * AUC.cm2km**2
fmass = helper.fmass_nfw(self.f_lturb)
v2_turb = v2_vir * (self.eta_turb / fmass) * (self.M_sub / mass)
return np.sqrt(v2_turb)
- def _magnetic_field(self, t):
- """
- Calculate the mean magnetic field strength of the main cluster mass
- at the given (cosmic) time.
-
- Parameters
- ----------
- t : float
- The (cosmic) time/age.
- Unit: [Gyr]
-
- Returns
- -------
- B : float
- The mean magnetic field strength of the main cluster.
- Unit: [uG]
- """
- z = COSMO.redshift(t)
- mass = self._mass(t) # [Msun]
- B = helper.magnetic_field(mass=mass, z=z, configs=self.configs)
- return B
-
def _loss_ion(self, gamma, t):
"""
Energy loss through ionization and Coulomb collisions.
@@ -714,7 +701,7 @@ class RadioHalo:
"""
gamma = np.asarray(gamma)
z = COSMO.redshift(t)
- mass = self._mass(t)
+ mass = self.mass_main(t)
n_th = helper.density_number_thermal(mass, z) # [cm^-3]
loss = -3.79e4 * n_th * (1 + np.log(gamma/n_th) / 75)
return loss
@@ -729,7 +716,7 @@ class RadioHalo:
Ref.[sarazin1999],Eq.(6,7)
"""
gamma = np.asarray(gamma)
- B = self._magnetic_field(t) # [uG]
+ B = self.magnetic_field(t) # [uG]
z = COSMO.redshift(t)
loss = -4.32e-4 * gamma**2 * ((B/3.25)**2 + (1+z)**4)
return loss
diff --git a/fg21sim/extragalactic/clusters/main.py b/fg21sim/extragalactic/clusters/main.py
index fc5876f..04ed52d 100644
--- a/fg21sim/extragalactic/clusters/main.py
+++ b/fg21sim/extragalactic/clusters/main.py
@@ -183,7 +183,7 @@ class GalaxyClusters:
merger_mass1, merger_mass2 :
[Msun] masses of the main and sub clusters of each merger.
merger_z, merger_age : redshifts and cosmic ages [Gyr]
- of each merger event.
+ of each merger event, in backward time ordering.
"""
logger.info("Simulating merger histories for each cluster ...")
num = len(self.catalog)
@@ -267,16 +267,14 @@ class GalaxyClusters:
("M0", halo.M_obs), # [Msun]
("Rvir0", halo.radius_virial_obs), # [kpc]
("kT0", halo.kT_obs), # [keV]
- ("B0", halo.B_obs), # [uG] magnetic field at z_obs
+ ("B0", halo.B_obs), # [uG] magnetic field @ z_obs
("lon", cdict["lon"]), # [deg] longitude
("lat", cdict["lat"]), # [deg] longitude
- ("felong", cdict["felong"]), # Fraction of elongation
+ ("felong", cdict["felong"]), # fraction of elongation
("rotation", cdict["rotation"]), # [deg] rotation angle
("M_main", halo.M_main), # [Msun]
("M_sub", halo.M_sub), # [Msun]
- ("z_merger", halo.z_merger),
- ("kT_main", halo.kT_main), # [keV] main cluster kT at z_merger
- ("tback_merger", halo.tback_merger), # [Gyr]
+ ("kT_main", halo.kT_main), # [keV] main cluster kT @ z_merger
("time_turbulence", halo.time_turbulence), # [Gyr]
("Rhalo", halo.radius), # [kpc]
("Rhalo_angular", halo.angular_radius), # [arcsec]
@@ -288,7 +286,7 @@ class GalaxyClusters:
("n_e", n_e), # [cm^-3]
])
self.halos.append(data)
- logger.info("Simulated radio halos for merging cluster.")
+ logger.info("Simulated radio halos for clusters with recent mergers.")
def _calc_halos_emission(self):
"""