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authorAaron LI <aly@aaronly.me>2017-06-11 11:19:01 +0800
committerAaron LI <aly@aaronly.me>2017-06-11 11:23:18 +0800
commit8a41a25f708b031e8375a6ab75bd3adc20a20b47 (patch)
tree7edce614d78c211d666695fd8d752e13479117f4 /fg21sim
parent02b921d4e2748cc31f2d96f734d22b8ab34cdfba (diff)
downloadfg21sim-8a41a25f708b031e8375a6ab75bd3adc20a20b47.tar.bz2
clusters.py: Fix calculation on size_{major,minor}
The size_{major,minor} should be the major and minor (not semi-) axes of the cluster halo; but I originally calculated them as the semi-major and semi-minor axes. Also change the units of size_{major,minor} from [deg] to [arcmin].
Diffstat (limited to 'fg21sim')
-rw-r--r--fg21sim/extragalactic/clusters/clusters.py35
1 files changed, 20 insertions, 15 deletions
diff --git a/fg21sim/extragalactic/clusters/clusters.py b/fg21sim/extragalactic/clusters/clusters.py
index 68e1eb5..304603b 100644
--- a/fg21sim/extragalactic/clusters/clusters.py
+++ b/fg21sim/extragalactic/clusters/clusters.py
@@ -296,19 +296,22 @@ class GalaxyClusters:
catalog["r_vir"] : 1D `~numpy.ndarray`
The virial radii (unit: Mpc) calculated from the cluster masses
catalog["size_major"], catalog["size_minor] : 1D `~numpy.ndarray`
- The major and minor axes (unit: degree) of the clusters calculated
+ The major and minor axes (unit: arcmin) of the clusters calculated
from the above virial radii and the random eccentricities.
+ NOTE: These major and minor axes are corresponding to the
+ diameter values; NOT semi-major/semi-minor axes!
+ Unit: arcmin
NOTE
----
The elliptical major and minor axes are calculated by assuming
the equal area between the ellipse and corresponding circle.
- theta2 = r_vir / distance
+ theta2 = r_vir / distance # half angular size
pi * a * b = pi * (theta2)^2
- e = sqrt((a^2 - b^2) / a^2)
+ e = sqrt((a^2 - b^2) / a^2) # eccentricity
thus,
- a = theta2 / (1-e^2)^(1/4)
- b = theta2 * (1-e^2)^(1/4)
+ a = theta2 / (1-e^2)^(1/4) # semi-major axis
+ b = theta2 * (1-e^2)^(1/4) # semi-minor axis
"""
logger.info("Calculating the virial radii ...")
overdensity = self.catalog_prop["overdensity"]
@@ -321,12 +324,15 @@ class GalaxyClusters:
# Calculate (elliptical) angular sizes, i.e., major and minor axes
logger.info("Calculating the elliptical angular sizes ...")
distance = self.catalog["distance"].data * self.units["distance"]
- theta2 = (r_vir / distance).decompose().value # [ rad ]
- size_major = theta2 / (1 - self.catalog["eccentricity"]**2) ** 0.25
- size_minor = theta2 * (1 - self.catalog["eccentricity"]**2) ** 0.25
- self.catalog["size_major"] = size_major * au.rad.to(au.deg)
- self.catalog["size_minor"] = size_minor * au.rad.to(au.deg)
- self.units["size"] = au.deg
+ # Half angular size
+ theta2 = (r_vir / distance).decompose().value # [rad]
+ theta = theta2 * 2 # angular size
+ # Major and minor axes (corresponding to diameter values)
+ size_major = theta / (1 - self.catalog["eccentricity"]**2) ** 0.25
+ size_minor = theta * (1 - self.catalog["eccentricity"]**2) ** 0.25
+ self.catalog["size_major"] = size_major * au.rad.to(au.arcmin)
+ self.catalog["size_minor"] = size_minor * au.rad.to(au.arcmin)
+ self.units["size"] = au.arcmin
logger.info("Done calculate the elliptical angular sizes")
def _calc_luminosity(self):
@@ -506,7 +512,6 @@ class GalaxyClusters:
"""
logger.info("Simulating sky templates for each cluster/halo ...")
templates = []
- pixelsize_deg = self.resolution.to(au.deg).value
# Make sure the index is reset, therefore, the *row indexes* can be
# simply used to identify the corresponding template image.
self.catalog.reset_index(inplace=True)
@@ -514,8 +519,8 @@ class GalaxyClusters:
for row in self.catalog.itertuples():
# TODO: progress bar
gcenter = (row.glon, row.glat) # [ deg ]
- radii = (int(np.ceil(row.size_major * 0.5 / pixelsize_deg)),
- int(np.ceil(row.size_minor * 0.5 / pixelsize_deg)))
+ radii = (int(np.ceil(row.size_major * 0.5 / self.resolution)),
+ int(np.ceil(row.size_minor * 0.5 / self.resolution)))
rmax = max(radii)
pcenter = (rmax, rmax)
image = make_ellipse(pcenter, radii, row.rotation)
@@ -559,7 +564,7 @@ class GalaxyClusters:
luminosity = data.luminosity
distance = data.distance
specindex = data.specindex
- size = (data.size_major, data.size_minor) # [ deg ]
+ size = (data.size_major/60.0, data.size_minor/60.0) # [deg]
Tb = self._calc_Tb(luminosity, distance, specindex, frequency, size)
val = val * Tb
return (idx, val)