update FSPS and add access to the young and old components of the sed…

src/fsps/fsps.f90

@@ -380,6 +380,19 @@ subroutine get_ssp_weights(n_age, n_z, ssp_wghts_out)
 
   end subroutine
 
+  subroutine get_csp_components(ns, csp1, csp2)
+
+    ! Return the unattenuated 'young' and 'old' stellar continuua
+
+    implicit none
+    integer, intent(in) :: ns
+    double precision, dimension(ns), intent(inout) :: csp1, csp2
+    csp1 = spec_young
+    csp2 = spec_old
+
+  end subroutine
+
+
   subroutine get_ssp_spec(ns,n_age,n_z,ssp_spec_out,ssp_mass_out,ssp_lbol_out)
 
     ! Return the contents of the ssp spectral array,

src/fsps/fsps.py

@@ -781,6 +781,23 @@ def _all_ssp_spec(self, update=True, peraa=False):
 
         return spec, mass, lbol
 
+    @property
+    def _csp_young_old(self):
+        """Get the (unattenuated) young and old component spectra of the CSP
+
+        :returns young:
+            The young stellar spectrum
+
+        :returns old:
+            The old stellar spectrum
+        """
+
+        NS = driver.get_nspec()
+        young, old = np.zeros(NS), np.zeros(NS)
+        driver.get_csp_components(young, old)
+        return young, old
+
+    @property
     def _ssp_weights(self):
          """Get the weights of the SSPs for the CSP
 

tests/tests.py

@@ -394,7 +394,7 @@ def test_ssp_weights(pop_and_params):
 
     wave, spec = pop.get_spectrum(tage=age.max())
     mstar = pop.stellar_mass
-    wght = pop._ssp_weights()
+    wght = pop._ssp_weights
     ssp, smass, slbol = pop._all_ssp_spec()
 
     assert np.allclose((smass[:, zind] * wght[:, 0]).sum(), mstar)