Extra AGN spin jet debugging

doc/RTD/source/SubgridModels/AGNSpinJets/params.rst

@@ -55,6 +55,7 @@ Below we give an example of parameter choices applicable for e.g. a 50 Mpc box.
         v_jet_cs_ratio:                     10.        # This sets the jet velocity to v_jet_cs_ratio times the sound speed of the hot gas of the parent halo the black hole is in. This is used if 'AGN_jet_velocity_model' is 'BlackHoleMass'.
         v_jet_BH_mass_scaling_reference_mass_Msun: 3.4e3 # The reference mass used in the relation between halo mass and BH mass used to calculate jet velocities. Only used if 'AGN_jet_velocity_model' is 'BlackHoleMass'.
         v_jet_BH_mass_scaling_slope:        0.65       # The slope of the relation between halo mass and BH mass used to calculate jet velocities. Only used if 'AGN_jet_velocity_model' is 'BlackHoleMass'.
+        v_jet_min_km_p_s:                   500        # The minimal jet velocity. Only used if 'AGN_jet_velocity_model' is 'BlackHoleMass'.
         opening_angle_in_degrees:           7.5        # The half-opening angle of the jet in degrees. Should use values < 15 unless for tests.
         N_jet:                              2          # Target number of particles to kick as part of a single jet feedback event. Should be a multiple of 2 to ensure approximate momentum conservation (we always kick particles in pairs, one from each 'side' of the BH, relative to the spin vector).
         AGN_jet_feedback_model:             SpinAxis   # Which particles to kick from the black hole smoothing kernels. Should be 'SpinAxis', 'MinimumDistance', 'MaximumDistance' or 'MinimumDensity'

examples/parameter_example.yml

@@ -705,6 +705,7 @@ SPINJETAGN:
   v_jet_cs_ratio:                     10.        # This sets the jet velocity to v_jet_cs_ratio times the sound speed of the hot gas of the parent halo the black hole is in. This is used if 'AGN_jet_velocity_model' is 'BlackHoleMass'.
   v_jet_BH_mass_scaling_reference_mass_Msun: 3.4e3 # The reference mass used in the relation between halo mass and BH mass used to calculate jet velocities. Only used if 'AGN_jet_velocity_model' is 'BlackHoleMass'.
   v_jet_BH_mass_scaling_slope:        0.65       # The slope of the relation between halo mass and BH mass used to calculate jet velocities. Only used if 'AGN_jet_velocity_model' is 'BlackHoleMass'.
+  v_jet_min_km_p_s:                   500        # The minimal jet velocity. Only used if 'AGN_jet_velocity_model' is 'BlackHoleMass'.
   opening_angle_in_degrees:           7.5        # The half-opening angle of the jet in degrees. Should use values < 15 unless for tests.
   N_jet:                              2          # Target number of particles to kick as part of a single jet feedback event. Should be a multiple of 2 to ensure approximate momentum conservation (we always kick particles in pairs, one from each 'side' of the BH, relative to the spin vector).
   AGN_jet_feedback_model:             SpinAxis   # Which particles to kick from the black hole smoothing kernels. Should be 'SpinAxis', 'MinimumDistance', 'MaximumDistance' or 'MinimumDensity'

src/black_holes/SPIN_JET/black_holes.h

@@ -943,10 +943,11 @@ __attribute__((always_inline)) INLINE static void black_holes_prepare_feedback(
   bp->total_accreted_mass = bp->total_accreted_mass + delta_m_real;
 
   if (bp->subgrid_mass < 0.) {
-    error(
+    warning(
         "Black hole %lld has reached a negative mass (%f) due"
         " to jet spindown.",
         bp->id, bp->subgrid_mass);
+    bp->subgrid_mass = props->subgrid_seed_mass;
   }
 
   /* Update other quantities. */

src/black_holes/SPIN_JET/black_holes_properties.h

@@ -345,6 +345,7 @@ struct black_holes_props {
   /*! Parameters of the scaling between AGN jet velocity and BH mass */
   float v_jet_BH_mass_scaling_reference_mass;
   float v_jet_BH_mass_scaling_slope;
+  float v_jet_min;
 
   /*! Sets the launching velocity of the jet to v_jet_cs_ratio times the
       sound speed of the hot gas in the halo, assuming it is at virial
@@ -824,6 +825,9 @@ INLINE static void black_holes_props_init(struct black_holes_props *bp,
     bp->v_jet_BH_mass_scaling_slope = parser_get_param_float(
         params, "SPINJETAGN:v_jet_BH_mass_scaling_slope");
 
+    bp->v_jet_min =
+        parser_get_param_float(params, "SPINJETAGN:v_jet_min_km_p_s");
+
     bp->v_jet_cs_ratio =
         parser_get_param_float(params, "SPINJETAGN:v_jet_cs_ratio");
 

src/black_holes/SPIN_JET/black_holes_spin.h

@@ -809,7 +809,7 @@ __attribute__((always_inline)) INLINE static float da_dln_mbh_0(
     const struct black_holes_props* props) {
   const float a = bp->spin;
 
-  if ((a == 0.) || (a < -0.998) || (a > 0.998)) {
+  if ((a == 0.) || (a < -0.9981) || (a > 0.9981)) {
     error(
         "The da_dln_mbh_0 function was called and spin is %f. Spin should "
         " not be a = 0, a < -0.998 or a > 0.998.",
@@ -877,7 +877,8 @@ __attribute__((always_inline)) INLINE static float black_hole_feedback_dv_jet(
     const float sound_speed = sqrtf(5. / 3. * 0.5) * virial_velocity;
 
     /* Return the jet velocity as some factor times the sound speed */
-    v_jet = props->v_jet_cs_ratio * sound_speed;
+    v_jet = fmaxf(props->v_jet_min, props->v_jet_cs_ratio * sound_speed);
+
   } else if (props->AGN_jet_velocity_model == AGN_jet_velocity_constant) {
     v_jet = props->v_jet;
   } else {