Create combined sky map and spacetime coincidence FAR automatically

Similar to waiting for g-events to be complete, we will wait to compare or combine sky maps until the external event is complete:

• comparing: when there is a coincidence (EM_COINC), and both sky maps are available (se: SKYMAP_READY, ext: LUMIN_GO)
• combine: when there is a raven alert (RAVEN_ALERT), and both sky maps are available (se: SKYMAP_READY, ext: LUMIN_GO)

If the external event is not complete we will look whether a superevent sky map is available and apply SKYMAP_READY if it is. Note we also apply SKYMAP_READY to all related external events when the superevent sky map is first available. The first case catches times where the superevent sky map comes in after the coincidence is found (EM_COINC applied) and the latter case catches time where the superevent sky map comes in before the coincidence is found.

gwcelery/tasks/raven.py

@@ -36,19 +36,6 @@ def calculate_coincidence_far(superevent, exttrig, group):
     if exttrig['pipeline'] == 'SNEWS':
         return
 
-    #  Try to grab superevent and external sky maps
-    try:
-        se_skymap = external_skymaps.get_preferred_skymap(
-            superevent_id)
-    except ValueError:
-        se_skymap = None
-    try:
-        ext_skymap = gracedb.download('glg_healpix_all_bn_v00.fit',
-                                      exttrig_id)
-    except HTTPError as e:
-        if e.status == 404:
-            ext_skymap = None
-
     tl_cbc, th_cbc = app.conf['raven_coincidence_windows']['GRB_CBC']
     tl_burst, th_burst = app.conf['raven_coincidence_windows']['GRB_Burst']
 
@@ -56,25 +43,24 @@ def calculate_coincidence_far(superevent, exttrig, group):
         tl, th = tl_cbc, th_cbc
     elif group == 'Burst':
         tl, th = tl_burst, th_burst
-
-    if ext_skymap and se_skymap:
-        return calc_signif(exttrig['search'],
-                           superevent_id, exttrig_id, tl, th,
-                           incl_sky=True,
-                           se_fitsfile=se_skymap)
+     
+    if {'LUMIN_GO', 'SKYMAP_READY'}.issubset(exttrig['labels']):
+        #  if both sky maps available, calculate spat coinc far
+        se_skymap = external_skymaps.get_preferred_skymap(
+            superevent_id)
+        ext_skymap = external_skymaps.get_external_skymap_filename(
+            exttrig_id)
+
+        return ligo.raven.search.calc_signif_gracedb(
+                   superevent_id, exttrig_id, tl, th,
+                   grb_search=exttrig['search'],
+                   se_fitsfile=se_skymap, ext_fitsfile=ext_skymap,
+                   incl_sky=True, gracedb=gracedb.client)
     else:
-        return calc_signif(exttrig['search'],
-                           superevent_id, exttrig_id, tl, th,
-                           incl_sky=False)
-
-
-@app.task(shared=False)
-def calc_signif(search, se_id, exttrig_id, tl, th, incl_sky=False,
-                se_fitsfile=None):
-    """Calculate FAR of GRB exttrig-GW coincidence"""
-    return ligo.raven.search.calc_signif_gracedb(
-        se_id, exttrig_id, tl, th, grb_search=search, se_fitsfile=se_fitsfile,
-        incl_sky=incl_sky, gracedb=gracedb.client)
+         return ligo.raven.search.calc_signif_gracedb(
+                   superevent_id, exttrig_id, tl, th,
+                   grb_search=exttrig['search'],
+                   incl_sky=False, gracedb=gracedb.client)
 
 
 @app.task(shared=False)