I am using the following code to add a feature to a vector layer in OpenLayers 3 (OL3):

```
marker = new ol.Feature({
    geometry: new ol.geom.Point([longitude, latitude]),
    name: "Location Marker"
});
markerStyle = new ol.style.Style({
  image: new ol.style.Icon({
    anchor: [0.5, 1.0],
    anchorXUnits: "fraction",
    anchorYUnits: "fraction",
    src: "Content/Images/OpenLayers/marker_trans.png"
  }),
  zIndex: 100000
});
marker.setStyle(markerStyle);
marker.on("click", function(e) {
  // do something
}, marker);
map.getSource().addFeature(marker);

```

The marker displays as expected, but the click event never fires. What am I doing wrong?

I should note that there is already a handler associated with "click" at the map level, i.e.

```
map.on("click", function(e) {
  // do something
}, marker);

```