Import the sample SNII code from COLIBRE into the EAGLE feedback. Set the min...

Import the sample SNII code from COLIBRE into the EAGLE feedback. Set the min SNII mass in the EAGLE ICs to 8 Msun.

doc/RTD/source/SubgridModels/EAGLE/index.rst

@@ -647,9 +647,10 @@ Supernova feedback: Dalla Vecchia+2012 & Schaye+2015
     filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
     IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
     IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-    SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-    SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-    SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+    SNII_min_mass_Msun:               8.0             # Minimal mass considered for SNII stars in solar masses.
+    SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+    SNII_sampled_delay:               1               # Sample the SNII lifetimes to do feedback.
+    SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
     SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
     SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
     SNII_energy_fraction_min:         0.3             # Maximal fraction of energy applied in a SNII feedback event.
@@ -681,7 +682,8 @@ different from the value (:math:`0.67`) reported in table 3 of `Schaye
 of :math:`h^{-2} = 0.6777^{-2} = 2.1773` is missing in the paper.
 
 The Magnesium yields from SNII have also been doubled since the
-original EAGLE simulations were run.
+original EAGLE simulations were run and the minimal mass for SNII stars has
+been raised to 8 solar masses (from 6).
 
 
     

examples/EAGLE_ICs/EAGLE_12/eagle_12.yml

@@ -143,9 +143,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               8.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               1               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              dummy           # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         0.3             # Minimal fraction of energy applied in a SNII feedback event.

examples/EAGLE_ICs/EAGLE_25/eagle_25.yml

@@ -144,9 +144,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               8.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               1               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              dummy           # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         0.3             # Minimal fraction of energy applied in a SNII feedback event.

examples/EAGLE_ICs/EAGLE_50/eagle_50.yml

@@ -144,9 +144,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               8.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               1               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              dummy           # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         0.3             # Minimal fraction of energy applied in a SNII feedback event.

examples/EAGLE_low_z/EAGLE_12/eagle_12.yml

@@ -140,9 +140,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               0               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         0.3             # Minimal fraction of energy applied in a SNII feedback event.

examples/EAGLE_low_z/EAGLE_25/eagle_25.yml

@@ -148,9 +148,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               0               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         0.3             # Minimal fraction of energy applied in a SNII feedback event.

examples/EAGLE_low_z/EAGLE_50/eagle_50.yml

@@ -139,9 +139,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               0               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         0.3             # Minimal fraction of energy applied in a SNII feedback event.

examples/EAGLE_low_z/EAGLE_6/eagle_6.yml

@@ -149,9 +149,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               0               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         0.3             # Minimal fraction of energy applied in a SNII feedback event.

examples/IsolatedGalaxy/IsolatedGalaxy_feedback/isolated_galaxy.yml

@@ -124,9 +124,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               0               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         1.0             # Minimal fraction of energy applied in a SNII feedback event.

examples/SubgridTests/CosmologicalStellarEvolution/stellar_evolution.yml

@@ -94,9 +94,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               0               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         0.3             # Minimal fraction of energy applied in a SNII feedback event.

examples/SubgridTests/StellarEvolution/stellar_evolution.yml

@@ -88,9 +88,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               0               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         0.3             # Minimal fraction of energy applied in a SNII feedback event.

examples/parameter_example.yml

@@ -393,9 +393,10 @@ EAGLEFeedback:
   filename:                         ./yieldtables/  # Path to the directory containing the EAGLE yield tables.
   IMF_min_mass_Msun:                0.1             # Minimal stellar mass considered for the Chabrier IMF in solar masses.
   IMF_max_mass_Msun:              100.0             # Maximal stellar mass considered for the Chabrier IMF in solar masses.
-  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII feedback (not SNII enrichment!) in solar masses.
-  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event.
+  SNII_min_mass_Msun:               6.0             # Minimal mass considered for SNII stars in solar masses.
+  SNII_max_mass_Msun:             100.0             # Maximal mass considered for SNII stars in solar masses.
+  SNII_sampled_delay:               1               # Sample the SNII lifetimes to do feedback.
+  SNII_wind_delay_Gyr:              0.03            # Time in Gyr between a star's birth and the SNII thermal feedback event when not sampling.
   SNII_delta_T_K:                   3.16228e7       # Change in temperature to apply to the gas particle in a SNII thermal feedback event in Kelvin.
   SNII_energy_erg:                  1.0e51          # Energy of one SNII explosion in ergs.
   SNII_energy_fraction_min:         0.3             # Maximal fraction of energy applied in a SNII feedback event.

src/feedback/EAGLE/feedback.c

@@ -44,7 +44,7 @@ double eagle_feedback_temperature_change(const struct spart* sp,
 
 /**
  * @brief Computes the number of supernovae of type II exploding for a given
- * star particle.
+ * star particle assuming that all the SNII stars go off at once.
  *
  * @param sp The #spart.
  * @param props The properties of the stellar model.
@@ -52,11 +52,113 @@ double eagle_feedback_temperature_change(const struct spart* sp,
 double eagle_feedback_number_of_SNII(const struct spart* sp,
                                      const struct feedback_props* props) {
 
-  /* Note: For a Chabrier 2003 IMF and SNII going off between 6 and 100
-   * M_sun, the first term is 0.017362 M_sun^-1 */
+  /* Note: For a Chabrier 2003 IMF and SNII going off
+   * - between 6 and 100 M_sun, the first term is 0.017362 M_sun^-1 (EAGLE)
+   * - between 8 and 100 M_sun, the first term is 0.011801 M_sun^-1 (EAGLE-XL)
+   */
   return props->num_SNII_per_msun * sp->mass_init * props->mass_to_solar_mass;
 }
 
+/**
+ * @brief Computes the number of supernovae of type II exploding for a given
+ * star particle between two mass limits
+ *
+ * @param sp The #spart.
+ * @param props The properties of the stellar model.
+ * @param min_dying_mass_Msun Minimal star mass dying this step (in solar
+ * masses).
+ * @param max_dying_mass_Msun Maximal star mass dying this step (in solar
+ * masses).
+ */
+double eagle_feedback_number_of_sampled_SNII(const struct spart* sp,
+                                             const struct feedback_props* props,
+                                             const double min_dying_mass_Msun,
+                                             const double max_dying_mass_Msun) {
+
+  /* The max dying star mass is below the SNII mass window
+   * --> No SNII */
+  if (max_dying_mass_Msun < props->SNII_min_mass_msun) return 0.;
+
+  /* The min dying star mass is above the SNII mass window
+   * --> No SNII */
+  if (min_dying_mass_Msun > props->SNII_max_mass_msun) return 0.;
+
+  /* Ok, we have some overlap with the SNII mass window. */
+
+  double log10_min_mass_Msun = -10.;
+  double log10_max_mass_Msun = -10.;
+
+  /* The min dying star mass dies inside the SNII mass window */
+  if (min_dying_mass_Msun <= props->SNII_max_mass_msun &&
+      min_dying_mass_Msun > props->SNII_min_mass_msun) {
+
+    /* Now, check the max dying star mass */
+
+    /* The max dying star mass is also inside the SNII mass window */
+    if (max_dying_mass_Msun <= props->SNII_max_mass_msun) {
+      log10_min_mass_Msun = log10(min_dying_mass_Msun);
+      log10_max_mass_Msun = log10(max_dying_mass_Msun);
+    }
+
+    /* The max dying star is above the SNII mass window */
+    else {
+      log10_min_mass_Msun = log10(min_dying_mass_Msun);
+      log10_max_mass_Msun = props->log10_SNII_max_mass_msun;
+    }
+
+  }
+
+  /* The min dying star mass dies below the SNII mass window */
+  else if (min_dying_mass_Msun <= props->SNII_min_mass_msun) {
+
+    /* Now, check the max dying star mass */
+
+    /* The max dying star mass is inside the SNII mass window */
+    if (max_dying_mass_Msun > props->SNII_min_mass_msun &&
+        max_dying_mass_Msun <= props->SNII_max_mass_msun) {
+      log10_min_mass_Msun = props->log10_SNII_min_mass_msun;
+      log10_max_mass_Msun = log10(max_dying_mass_Msun);
+    }
+
+    /* The max dying star is above the SNII mass window */
+    else if (max_dying_mass_Msun > props->SNII_max_mass_msun) {
+      log10_min_mass_Msun = props->log10_SNII_min_mass_msun;
+      log10_max_mass_Msun = props->log10_SNII_max_mass_msun;
+    }
+
+    /* The max dying star mass is also below the SNII mass window */
+    else {
+
+    /* We already excluded this at the star of the function */
+#ifdef SWIFT_DEBUG_CHECKS
+      error("Error in the logic");
+#endif
+    }
+  }
+
+  /* The min dying star mass dies above the SNII mass window */
+  else {
+
+  /* We already excluded this at the star of the function */
+#ifdef SWIFT_DEBUG_CHECKS
+    error("Error in the logic");
+#endif
+  }
+
+#ifdef SWIFT_DEBUG_CHECKS
+  if (log10_min_mass_Msun == -10. || log10_max_mass_Msun == -10.)
+    error("Something went wrong in the calculation of the number of SNII.");
+#endif
+
+  /* Calculate how many supernovae have exploded in this timestep
+   * by integrating the IMF between the bounds we chose */
+  const double num_SNII_per_msun =
+      integrate_imf(log10_min_mass_Msun, log10_max_mass_Msun,
+                    eagle_imf_integration_no_weight, NULL, props);
+
+  return num_SNII_per_msun * sp->mass_init * props->mass_to_solar_mass;
+}
+
 /**
  * @brief Computes the number of supernovae of type Ia exploding for a given
  * star particle between time t0 and t1
@@ -161,22 +263,32 @@ double eagle_feedback_energy_fraction(const struct spart* sp,
  * @param dt Length of time-step in internal units.
  * @param ngb_gas_mass Total un-weighted mass in the star's kernel.
  * @param feedback_props The properties of the feedback model.
+ * @param min_dying_mass_Msun Minimal star mass dying this step (in solar
+ * masses).
+ * @param max_dying_mass_Msun Maximal star mass dying this step (in solar
+ * masses).
  */
 INLINE static void compute_SNII_feedback(
     struct spart* sp, const double star_age, const double dt,
-    const float ngb_gas_mass, const struct feedback_props* feedback_props) {
+    const float ngb_gas_mass, const struct feedback_props* feedback_props,
+    const double min_dying_mass_Msun, const double max_dying_mass_Msun) {
 
-  /* Time after birth considered for SNII feedback (internal units) */
+  /* Are we sampling the delay function or using a fixed delay? */
+  const int SNII_sampled_delay = feedback_props->SNII_sampled_delay;
+
+  /* Time after birth considered for SNII feedback (internal units)
+   * when using a fixed delay */
   const double SNII_wind_delay = feedback_props->SNII_wind_delay;
 
   /* Are we doing feedback this step?
    * Note that since the ages are calculated using an interpolation table we
    * must allow some tolerance here*/
-  if (star_age <= SNII_wind_delay &&
-      (star_age + 1.0001 * dt) > SNII_wind_delay) {
+  if ((SNII_sampled_delay) || (star_age <= SNII_wind_delay &&
+                               (star_age + 1.001 * dt) > SNII_wind_delay)) {
 
-    /* Make sure a star does not do feedback twice! */
-    if (sp->f_E != -1.f) {
+    /* Make sure a star does not do feedback twice
+     * when using a fixed delay! */
+    if (!SNII_sampled_delay && sp->f_E != -1.f) {
 #ifdef SWIFT_DEBUG_CHECKS
       message("Star has already done feedback! sp->id=%lld age=%e d=%e", sp->id,
               star_age, dt);
@@ -187,10 +299,21 @@ INLINE static void compute_SNII_feedback(
     /* Properties of the model (all in internal units) */
     const double delta_T =
         eagle_feedback_temperature_change(sp, feedback_props);
-    const double N_SNe = eagle_feedback_number_of_SNII(sp, feedback_props);
     const double E_SNe = feedback_props->E_SNII;
     const double f_E = eagle_feedback_energy_fraction(sp, feedback_props);
 
+    /* Number of SNe at this time-step */
+    double N_SNe;
+    if (SNII_sampled_delay) {
+      N_SNe = eagle_feedback_number_of_sampled_SNII(
+          sp, feedback_props, min_dying_mass_Msun, max_dying_mass_Msun);
+    } else {
+      N_SNe = eagle_feedback_number_of_SNII(sp, feedback_props);
+    }
+
+    /* Abort if there are no SNe exploding this step */
+    if (N_SNe == 0.) return;
+
     /* Conversion factor from T to internal energy */
     const double conv_factor = feedback_props->temp_to_u_factor;
 
@@ -720,7 +843,7 @@ void compute_stellar_evolution(const struct feedback_props* feedback_props,
 #endif
 
   /* Convert dt and stellar age from internal units to Gyr. */
-  const double Gyr_in_cgs = 1e9 * 365. * 24. * 3600.;
+  const double Gyr_in_cgs = 1e9 * 365.25 * 24. * 3600.;
   const double time_to_cgs = units_cgs_conversion_factor(us, UNIT_CONV_TIME);
   const double conversion_factor = time_to_cgs / Gyr_in_cgs;
   const double dt_Gyr = dt * conversion_factor;
@@ -772,11 +895,6 @@ void compute_stellar_evolution(const struct feedback_props* feedback_props,
     error("Negative weight!");
 #endif
 
-  /* Compute properties of the stochastic SNII feedback model. */
-  if (feedback_props->with_SNII_feedback) {
-    compute_SNII_feedback(sp, age, dt, ngb_gas_mass, feedback_props);
-  }
-
   /* Calculate mass of stars that has died from the star's birth up to the
    * beginning and end of timestep */
   const double max_dying_mass_Msun =
@@ -784,13 +902,19 @@ void compute_stellar_evolution(const struct feedback_props* feedback_props,
   const double min_dying_mass_Msun =
       dying_mass_msun(star_age_Gyr + dt_Gyr, Z, feedback_props);
 
-#ifdef SWIFT_DEBUG_CHECK
+#ifdef SWIFT_DEBUG_CHECKS
   /* Sanity check. Worth investigating if necessary as functions for evaluating
    * mass of stars dying might be strictly decreasing.  */
   if (min_dying_mass_Msun > max_dying_mass_Msun)
     error("min dying mass is greater than max dying mass");
 #endif
 
+  /* Compute properties of the stochastic SNII feedback model. */
+  if (feedback_props->with_SNII_feedback) {
+    compute_SNII_feedback(sp, age, dt, ngb_gas_mass, feedback_props,
+                          min_dying_mass_Msun, max_dying_mass_Msun);
+  }
+
   /* Integration interval is zero - this can happen if minimum and maximum
    * dying masses are above imf_max_mass_Msun. Return without doing any
    * enrichment. */
@@ -896,11 +1020,18 @@ void feedback_props_init(struct feedback_props* fp,
 
   /* Properties of the SNII energy feedback model ------------------------- */
 
-  /* Set the delay time before SNII occur */
-  const double Gyr_in_cgs = 1.0e9 * 365. * 24. * 3600.;
-  fp->SNII_wind_delay =
-      parser_get_param_double(params, "EAGLEFeedback:SNII_wind_delay_Gyr") *
-      Gyr_in_cgs / units_cgs_conversion_factor(us, UNIT_CONV_TIME);
+  /* Are we sampling the SNII lifetimes for feedback or using a fixed delay? */
+  fp->SNII_sampled_delay =
+      parser_get_param_int(params, "EAGLEFeedback:SNII_sampled_delay");
+
+  if (!fp->SNII_sampled_delay) {
+
+    /* Set the delay time before SNII occur */
+    const double Gyr_in_cgs = 1.0e9 * 365.25 * 24. * 3600.;
+    fp->SNII_wind_delay =
+        parser_get_param_double(params, "EAGLEFeedback:SNII_wind_delay_Gyr") *
+        Gyr_in_cgs / units_cgs_conversion_factor(us, UNIT_CONV_TIME);
+  }
 
   /* Read the temperature change to use in stochastic heating */
   fp->SNe_deltaT_desired =
@@ -925,6 +1056,8 @@ void feedback_props_init(struct feedback_props* fp,
     error("Can't have the max SNII mass smaller than the min SNII mass!");
   }
 
+  fp->SNII_min_mass_msun = SNII_min_mass_msun;
+  fp->SNII_max_mass_msun = SNII_max_mass_msun;
   fp->log10_SNII_min_mass_msun = log10(SNII_min_mass_msun);
   fp->log10_SNII_max_mass_msun = log10(SNII_max_mass_msun);
 

src/feedback/EAGLE/feedback_properties.h

@@ -212,6 +212,12 @@ struct feedback_props {
 
   /* ------------ SNe feedback properties ------------ */
 
+  /*! Minimal stellar mass considered for SNII feedback (in solar masses) */
+  double SNII_min_mass_msun;
+
+  /*! Maximal stellar mass considered for SNII feedback (in solar masses) */
+  double SNII_max_mass_msun;
+
   /*! Log 10 of the minimal stellar mass considered for SNII feedback (in solar
    * masses) */
   double log10_SNII_min_mass_msun;
@@ -223,7 +229,10 @@ struct feedback_props {
   /*! Number of type II supernovae per solar mass */
   float num_SNII_per_msun;
 
-  /*! Wind delay time for SNII */
+  /*! Are we sampling the SNII life-times or using a fixed delay? */
+  int SNII_sampled_delay;
+
+  /*! Wind delay time for SNII when using a fixed delay */
   double SNII_wind_delay;
 
   /*! Temperature increase induced by SNe feedback */