[plotter] [postprocessor] make particles scatter actually work

plotter.py

@@ -695,9 +695,10 @@ class Plotter(Aggregator, BaseProcessor):
         """
 
         # Open particle HDF5 file
-        filename = self.save.get_node("/hdf5/particles").read()
-        hdf5_parts = tables.open(filename, "r")
+        filename = self.save.get_node("/hdf5/particles").read()[0].decode()
+        hdf5_parts = tables.open_file(filename, "r")
         part_pos = hdf5_parts.get_node("/data/pos").read()
+        hdf5_parts.close()
 
         # index of the horizontal axis
         ih = self._ax_nb[self._axes_h[ax_los]]
@@ -713,7 +714,7 @@ class Plotter(Aggregator, BaseProcessor):
         part_v = im_extent[2] + (im_extent[3] - im_extent[2]) * part_v
 
         # Scatter plot
-        plt.scatter(part_h, part_v)
+        plt.scatter(part_h, part_v, **kwargs)
 
     def _overlay_speed(
         self, ax_los, im_extent, unit=U.km_s, unit_coeff=1.0, key_v=None, **kwargs