From 7473c9374f31f4f8fc10d47c3ed7c85689b1be05 Mon Sep 17 00:00:00 2001 From: Aaron LI Date: Thu, 4 Jan 2018 21:40:28 +0800 Subject: clusters/halo: small updates and some cleanups --- fg21sim/extragalactic/clusters/halo.py | 93 +++++++++++++++------------------- fg21sim/extragalactic/clusters/main.py | 12 ++--- 2 files changed, 45 insertions(+), 60 deletions(-) (limited to 'fg21sim/extragalactic/clusters') 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() @@ -183,25 +185,13 @@ 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): """ -- cgit v1.2.2