diff options
| -rw-r--r-- | fg21sim/configs/20-extragalactic.conf.spec | 2 | ||||
| -rw-r--r-- | fg21sim/extragalactic/clusters/halo.py | 26 | ||||
| -rw-r--r-- | fg21sim/extragalactic/clusters/solver.py | 2 |
3 files changed, 27 insertions, 3 deletions
diff --git a/fg21sim/configs/20-extragalactic.conf.spec b/fg21sim/configs/20-extragalactic.conf.spec index 633ef78..de6dbeb 100644 --- a/fg21sim/configs/20-extragalactic.conf.spec +++ b/fg21sim/configs/20-extragalactic.conf.spec @@ -71,7 +71,7 @@ # Minimum and maximum Lorentz factor (i.e., energy) of the relativistic # electron spectrum. pmin = float(default=1.0) - pmax = float(default=1e4) + pmax = float(default=1e5) # Number of points for the grid used during solving the Fokker-Planck # equation to calculate the electron spectrum. diff --git a/fg21sim/extragalactic/clusters/halo.py b/fg21sim/extragalactic/clusters/halo.py index 072cdff..6adfba5 100644 --- a/fg21sim/extragalactic/clusters/halo.py +++ b/fg21sim/extragalactic/clusters/halo.py @@ -447,6 +447,27 @@ class HaloSingle: Calculate the electron-acceleration coefficient at arbitrary redshift, by interpolating the coefficients calculated at every merger redshifts. + + Parameters + ---------- + z : float + Redshift where to calculate the acceleration coefficient. + + Returns + ------- + chi : float + The calculated electron-acceleration coefficient. + (unit: Gyr^-1) + + XXX/NOTE + -------- + This coefficient may be very small and even zero, then the + diffusion coefficient of the Fokker-Planck equation is thus + very small and even zero, which cause problems for calculating + some quantities (e.g., w(x), C(x)) and wrong/invalid results. + To avoid these problems, force the minimal value of this + coefficient to be 1/(10*t0), which t0 is the present-day age + of the universe. """ if not hasattr(self, "_coef_acceleration_interp"): # Order the merger events by decreasing redshifts @@ -454,9 +475,12 @@ class HaloSingle: redshifts = np.array([ev["z"] for ev in mevents]) chis = np.array([self._chi_at_zidx(zidx, mevents) for zidx in range(len(redshifts))]) + # XXX: force a minimal value instead of zero or too small + chi_min = 1.0 / (10 * self.cosmo.age0) + chis[chis < chi_min] = chi_min self._coef_acceleration_interp = scipy.interpolate.interp1d( redshifts, chis, kind="linear", - bounds_error=False, fill_value=0.0) + bounds_error=False, fill_value=chi_min) logger.info("Interpolated acceleration coefficients w.r.t. z") return self._coef_acceleration_interp(z) diff --git a/fg21sim/extragalactic/clusters/solver.py b/fg21sim/extragalactic/clusters/solver.py index c1f01d1..9d4a781 100644 --- a/fg21sim/extragalactic/clusters/solver.py +++ b/fg21sim/extragalactic/clusters/solver.py @@ -58,7 +58,7 @@ class FokkerPlanckSolver: u(x,t) : distribution/spectrum w.r.t. x at different times B(x,t) : advection coefficient - C(x,t) : diffusion coefficient (>=0) + C(x,t) : diffusion coefficient (>0) Q(x,t) : injection coefficient (>=0) References |