Specify source also via coordinates

docs/source/changes/36.added.rst

@@ -0,0 +1 @@
+Allow to define a source also via its celestial coordinates.

src/iact_estimator/core.py

@@ -4,6 +4,8 @@
 import importlib
 
 import astropy.units as u
+from astropy.coordinates import SkyCoord
+from astroplan import FixedTarget
 from gammapy.stats import WStatCountsStatistic
 import numpy as np
 from scipy import interpolate
@@ -32,6 +34,35 @@
 logger = logging.getLogger(__name__)
 
 
+def load_target_source_coordinates(config):
+    """Load target source using celestial coordinates.
+
+    Parameters
+    ----------
+    config : dict
+        Loaded configuration file.
+
+    Returns
+    -------
+    target_source : `~astroplan.FixedTarget`
+    """
+    source_name = (
+        config["target_source"]["name"]
+        if config["target_source"]["name"]
+        else "test_source"
+    )
+
+    try:
+        coords = config["target_source"]["coordinates"]
+        target_source_coordinates = SkyCoord(
+            coords["ra_l"], coords["dec_b"], frame=coords["frame"].lower()
+        )
+        target_source = FixedTarget(coord=target_source_coordinates, name=source_name)
+    except ValueError:
+        logging.exception("Invalid target source coordinates.")
+    return target_source
+
+
 def setup_logging(log_level, source_name):
     """
     Create a logger.
@@ -213,17 +244,15 @@ def initialize_model(config):
     initialized_model : `~gammapy.modeling.models.SpectralModel`
         Initialized instance of a spectral model.
     """
-    model_name = config["assumed_model"]["name"]
+    assumed_model_cfg = config["target_source"]["assumed_model"]
+    model_name = assumed_model_cfg["name"]
     module_name = ".".join(model_name.split(".")[:-1])
     class_name = model_name.split(".")[-1]
     module = importlib.import_module(module_name)
     model = getattr(module, class_name)
-    model_parameters = config["assumed_model"]["parameters"]
+    model_parameters = assumed_model_cfg["parameters"]
 
-    if (
-        class_name == "LogParabolaSpectralModel"
-        and config["assumed_model"]["from_log10"]
-    ):
+    if class_name == "LogParabolaSpectralModel" and assumed_model_cfg["from_log10"]:
         initialized_model = model.from_log10(**model_parameters)
     else:
         initialized_model = model(**model_parameters)

src/iact_estimator/resources/config.yml

@@ -1,12 +1,19 @@
-assumed_model:
-  # see https://docs.gammapy.org/1.1/user-guide/model-gallery/index.html#spectral-models
-  name: gammapy.modeling.models.LogParabolaSpectralModel
-  parameters:
-    amplitude: 3.39e-11 TeV^-1 cm^-2 s^-1
-    reference: 1 TeV
-    alpha: 2.51
-    beta: 0.21
-  from_log10: True # relevant for e.g. LogParabolaSpectralModel
+target_source:
+  name: "Crab Nebula"
+  coordinates:
+    force: false # force use of custom coordinates for sources found also by name
+    ra_l:
+    dec_b:
+    frame:
+  assumed_model:
+    # see https://docs.gammapy.org/1.1/user-guide/model-gallery/index.html#spectral-models
+    name: gammapy.modeling.models.LogParabolaSpectralModel
+    parameters:
+      amplitude: 3.39e-11 TeV^-1 cm^-2 s^-1
+      reference: 1 TeV
+      alpha: 2.51
+      beta: 0.21
+    from_log10: True # relevant for e.g. LogParabolaSpectralModel
 
 observation_time: 50 h
 observation_datetime: "2024-06-15 18:00"

src/iact_estimator/scripts/main.py

@@ -6,6 +6,7 @@
 import shutil
 
 from astroplan import FixedTarget, Observer
+from astropy.coordinates.name_resolve import NameResolveError
 from astropy.time import Time
 import astropy.units as u
 from astropy.visualization import quantity_support
@@ -15,6 +16,7 @@
 from ..io import read_yaml
 from ..core import (
     setup_logging,
+    load_target_source_coordinates,
     initialize_model,
     check_input_configuration,
     prepare_data,
@@ -97,7 +99,15 @@ def main():
         output_path = (
             Path(args.output_path) if args.output_path is not None else Path.cwd()
         )
-        source_name = args.source_name
+
+        logging.info("Loading configuration file")
+        config = read_yaml(args.config)
+
+        source_name = (
+            config["target_source"]["name"]
+            if config["target_source"]["name"]
+            else "test_source"
+        )
 
         previous_output = len(
             [file for file in output_path.rglob(f"**/{source_name}*")]
@@ -109,9 +119,6 @@ def main():
 
         logger = setup_logging(args.log_level, source_name)
 
-        logger.info("Loading configuration file")
-        config = read_yaml(args.config)
-
         logging.info("Validating input configuration")
         if not check_input_configuration(config):
             logging.critical(
@@ -175,7 +182,17 @@ def main():
 
         logger.info("All expected operations have been perfomed succesfully.")
 
-        target_source = FixedTarget.from_name(source_name)
+        if source_name:
+            try:
+                target_source = FixedTarget.from_name(source_name)
+            except NameResolveError:
+                target_source = load_target_source_coordinates(config)
+        elif (
+            source_name != "test_source"
+            and config["target_source"]["coordinates"]["force"]
+        ):
+            target_source = load_target_source_coordinates(config)
+
         observer = Observer.at_site("Roque de los Muchachos")
         time = Time(config["observation_datetime"])