Update model fit result units after toggling flux/surface brightness (#…

…3113)

* Enabling model fitting results to convert between flux and surface brightness

* Switch to using selected_obj, clean up pixel scale retrieval

* Changelog

* Don't store pixel scale factor

* Fix missing variable

* Update test value due to updated pixel scale factor

CHANGES.rst

@@ -5,7 +5,7 @@ New Features
 ------------
 
 - Added flux/surface brightness translation and surface brightness
-  unit conversion in Cubeviz and Specviz. [#2781, #2940, #3088]
+  unit conversion in Cubeviz and Specviz. [#2781, #2940, #3088, #3113]
 
 - Plugin tray is now open by default. [#2892]
 

jdaviz/configs/cubeviz/plugins/spectral_extraction/spectral_extraction.py

@@ -513,7 +513,7 @@ def extract(self, return_bg=False, add_data=True, **kwargs):
             spec = spec - bg_spec
 
         # per https://jwst-docs.stsci.edu/jwst-near-infrared-camera/nircam-performance/nircam-absolute-flux-calibration-and-zeropoints # noqa
-        pix_scale_factor = self.aperture_area_along_spectral * self.spectral_cube.meta.get('PIXAR_SR', 1.0)  # noqa
+        pix_scale_factor = self.spectral_cube.meta.get('PIXAR_SR', 1.0)
         spec.meta['_pixel_scale_factor'] = pix_scale_factor
 
         # inform the user if scale factor keyword not in metadata

jdaviz/configs/default/plugins/model_fitting/model_fitting.py

@@ -328,7 +328,7 @@ def _dataset_selected_changed(self, event=None):
             # during initial init, this can trigger before the component is initialized
             return
 
-        selected_spec = self.dataset.selected_spectrum
+        selected_spec = self.dataset.selected_obj
         if selected_spec is None:
             return
 
@@ -842,6 +842,10 @@ def _fit_model_to_spectrum(self, add_data):
             self.hub.broadcast(msg)
             return
 
+        selected_spec = self.dataset.selected_obj
+        if '_pixel_scale_factor' in selected_spec.meta:
+            fitted_spectrum.meta['_pixel_scale_factor'] = selected_spec.meta['_pixel_scale_factor']
+
         self._fitted_model = fitted_model
         self._fitted_spectrum = fitted_spectrum
 
@@ -933,6 +937,10 @@ def _fit_model_to_cube(self, add_data):
 
         output_cube = Spectrum1D(flux=fitted_spectrum.flux, wcs=fitted_spectrum.wcs)
 
+        selected_spec = self.dataset.selected_obj
+        if '_pixel_scale_factor' in selected_spec.meta:
+            output_cube.meta['_pixel_scale_factor'] = selected_spec.meta['_pixel_scale_factor']
+
         # Create new data entry for glue
         if add_data:
             self.add_results.add_results_from_plugin(output_cube)

jdaviz/tests/test_app.py

@@ -232,7 +232,7 @@ def test_to_unit(cubeviz_helper):
 
     # will be a uniform array since not wavelength dependent
     # so test first value in array
-    assert np.allclose(value[0], 4.800000041882413e-08)
+    assert np.allclose(value[0], 8e-11)
 
     # Change from Fnu to Flam (with values shape matching spectral axis)