diff --git a/sunkit_instruments/response/tests/test_source_spectra.py b/sunkit_instruments/response/tests/test_source_spectra.py
new file mode 100644
index 00000000..4ae5f401
--- /dev/null
+++ b/sunkit_instruments/response/tests/test_source_spectra.py
@@ -0,0 +1,40 @@
+"""
+Smoke tests for SourceSpectra
+"""
+import numpy as np
+import pytest
+
+import astropy.units as u
+
+from sunkit_instruments.response import SourceSpectra
+
+
+@pytest.mark.parametrize(('density', 'meta'), [
+    (None, None),
+    (1e15*u.K/u.cm**3, None),
+    (None, {'abundance_model': 'test'}),
+    (1e15*u.K/u.cm**3, {'abundance_model': 'test'}),
+])
+def test_create_source_spectra(density, meta):
+    temperature = np.logspace(4, 9, 100) * u.K
+    wavelength = np.linspace(1, 1000, 50) * u.Angstrom
+    if density is not None:
+        density = density / temperature
+    data_shape = temperature.shape + wavelength.shape
+    data = np.random.rand(*data_shape) * u.Unit("photon cm3 s-1 sr-1 Angstrom-1")
+    spec = SourceSpectra(
+        temperature,
+        wavelength,
+        data,
+        density=density,
+        meta=meta,
+    )
+    assert isinstance(spec.meta, dict)
+    assert isinstance(spec.data, u.Quantity)
+    assert isinstance(spec.wavelength, u.Quantity)
+    assert isinstance(spec.temperature, u.Quantity)
+    if density is not None:
+        assert isinstance(spec.density, u.Quantity)
+    else:
+        with pytest.raises(ValueError, match="No density data available."):
+            spec.density
diff --git a/sunkit_instruments/response/thermal.py b/sunkit_instruments/response/thermal.py
index 6dc6a89d..7de91ee5 100644
--- a/sunkit_instruments/response/thermal.py
+++ b/sunkit_instruments/response/thermal.py
@@ -108,7 +108,7 @@ def meta(self, x):
         if x is None:
             self._meta = {}
         elif isinstance(x, dict):
-            self._mata = x
+            self._meta = x
         else:
             raise TypeError(f'Unsupported metadata type {type(x)}')
 
@@ -122,6 +122,14 @@ def temperature(self) -> u.K:
     def wavelength(self) -> u.Angstrom:
         return u.Quantity(self._da.wavelength.data, self._da.wavelength.attrs["unit"])
 
+    @property
+    @u.quantity_input
+    def density(self) -> u.cm**(-3):
+        if "density" in self._da.coords:
+            return u.Quantity(self._da.density.data, self._da.density.attrs["unit"])
+        else:
+            raise ValueError("No density data available.")
+
     @property
     @u.quantity_input
     def data(self) -> u.photon * u.cm**3 / (u.s * u.Angstrom * u.steradian):