Add the Kroupa IMF to the BPASS SED

SKIRT/core/BpassSED.cpp

@@ -14,8 +14,19 @@ const SEDFamily* BpassSED::getFamilyAndParameters(Array& parameters)
     // set the parameters using arbitrary scaling
     NR::assign(parameters, 1., _metallicity, _age);
 
-    // construct the library of SED models
-    return new BpassSEDFamily(this, BpassSEDFamily::IMF::Chabrier300, BpassSEDFamily::Resolution::Original);
+    // construct the appropriate library of SED models
+    auto imf = BpassSEDFamily::IMF::Chabrier100;
+    switch (_imf)
+    {
+        case IMF::Chabrier100: imf = BpassSEDFamily::IMF::Chabrier100; break;
+        case IMF::Chabrier300: imf = BpassSEDFamily::IMF::Chabrier300; break;
+        case IMF::Kroupa100: imf = BpassSEDFamily::IMF::Kroupa100; break;
+        case IMF::Kroupa300: imf = BpassSEDFamily::IMF::Kroupa300; break;
+    }
+    auto resolution = _resolution == Resolution::Downsampled ? BpassSEDFamily::Resolution::Downsampled
+                                                             : BpassSEDFamily::Resolution::Original;
+
+    return new BpassSEDFamily(this, imf, resolution);
 }
 
 ////////////////////////////////////////////////////////////////////

SKIRT/core/BpassSED.hpp

@@ -12,12 +12,32 @@
 
 /** BpassSED is a class that represents spectral energy distributions of simple stellar populations
     (SSPs), parameterized on metallicity and age according to the BPASS model that includes binary
-    stellar systems and that assumes a Chabrier IMF with an upper mass limit of 300 solar masses.
+    stellar systems and that assumes a Chabrier or Kroupa IMF with upper mass limits of 100 or 300 solar masses.
     See the BpassSEDFamily class for more information. */
 class BpassSED : public FamilySED
 {
+    /** The enumeration type indicating the IMF to use */
+    ENUM_DEF(IMF, Chabrier100, Chabrier300, Kroupa100, Kroupa300)
+        ENUM_VAL(IMF, Chabrier100, "Chabrier IMF (0.1-100 Msun)")
+        ENUM_VAL(IMF, Chabrier300, "Chabrier IMF (0.1-300 Msun)")
+        ENUM_VAL(IMF, Kroupa100, "Kroupa IMF (0.1-100 Msun)")
+        ENUM_VAL(IMF, Kroupa300, "Kroupa IMF (0.1-300 Msun)")
+    ENUM_END()
+
+    /** The enumeration type indicating the wavelength resolution and spectral range */
+    ENUM_DEF(Resolution, Original, Downsampled)
+        ENUM_VAL(Resolution, Original, "Original wavelength resolution and range")
+        ENUM_VAL(Resolution, Downsampled, "Downsampled wavelength resolution and extended wavelength range")
+    ENUM_END()
+
     ITEM_CONCRETE(BpassSED, FamilySED, "a BPASS single stellar population SED")
 
+        PROPERTY_ENUM(imf, IMF, "the assumed initial mass function")
+        ATTRIBUTE_DEFAULT_VALUE(imf, "Chabrier300")
+
+        PROPERTY_ENUM(resolution, Resolution, "the wavelength resolution")
+        ATTRIBUTE_DEFAULT_VALUE(resolution, "Original")
+
         PROPERTY_DOUBLE(metallicity, "the metallicity of the SSP")
         ATTRIBUTE_MIN_VALUE(metallicity, "[1e-5")
         ATTRIBUTE_MAX_VALUE(metallicity, "0.04]")

SKIRT/core/BpassSEDFamily.cpp

@@ -27,6 +27,8 @@ void BpassSEDFamily::setupSelfBefore()
     {
         case IMF::Chabrier100: name += "_Chabrier100"; break;
         case IMF::Chabrier300: name += "_Chabrier300"; break;
+        case IMF::Kroupa100: name += "_Kroupa100"; break;
+        case IMF::Kroupa300: name += "_Kroupa300"; break;
     }
     if (_resolution == Resolution::Downsampled) name += "_downsampled";
 

SKIRT/core/BpassSEDFamily.hpp

@@ -14,7 +14,8 @@
 /** An instance of the BpassSEDFamily class represents a BPASS family of single stellar population
     (SSP) %SED templates (Eldridge, Stanway et al, 2017, PASA 34, 58; Stanway and Eldridge, 2018,
     MNRAS, 479, 75). We use the BPASS data release version 2.2.1 (July 2018) of the model that
-    includes binary stellar systems and that assumes a Chabrier IMF.
+    includes binary stellar systems and that assumes Chabrier and Kroupa IMFs.
+
 
     The SED templates are parametrized on metallicity (1e-5 - 0.04) and age (1 Myr - 100 Gyr), and
     scale with the initial mass of the SSP.
@@ -24,6 +25,8 @@
     \em imf determines the IMF, more specifically the upper limit of the stellar mass range:
       - Chabrier100: Chabrier IMF with stellar masses from 0.1 to 100 \f$\mathrm{M}_\odot\f$
       - Chabrier300: Chabrier IMF with stellar masses from 0.1 to 300 \f$\mathrm{M}_\odot\f$
+      - Kroupa100: Kroupa IMF with stellar masses from 0.1 to 100 \f$\mathrm{M}_\odot\f$
+      - Kroupa300: Kroupa IMF with stellar masses from 0.1 to 100 \f$\mathrm{M}_\odot\f$
 
     \em resolution determines the spectral resolution and the wavelength coverage:
       - Original: the wavelength grid has a resolution of 1 Angstrom over the wavelength range
@@ -51,9 +54,11 @@
 class BpassSEDFamily : public SEDFamily
 {
     /** The enumeration type indicating the IMF to use */
-    ENUM_DEF(IMF, Chabrier100, Chabrier300)
+    ENUM_DEF(IMF, Chabrier100, Chabrier300, Kroupa100, Kroupa300)
         ENUM_VAL(IMF, Chabrier100, "Chabrier IMF (0.1-100 Msun)")
         ENUM_VAL(IMF, Chabrier300, "Chabrier IMF (0.1-300 Msun)")
+        ENUM_VAL(IMF, Kroupa100, "Kroupa IMF (0.1-100 Msun)")
+        ENUM_VAL(IMF, Kroupa300, "Kroupa IMF (0.1-300 Msun)")
     ENUM_END()
 
     /** The enumeration type indicating the wavelength resolution and spectral range */

SKIRT/resources/ExpectedResources.txt

@@ -1,5 +1,5 @@
 Core 8
-BPASS 2
+BPASS 3
 TODDLERS 2
 TODDLERS_Cloud_BPASS_chab100 2
 TODDLERS_Cloud_BPASS_chab300 2