From 038d47dbff7f5fb536386f7b9e4f5de3141136ba Mon Sep 17 00:00:00 2001 From: Aaron LI Date: Thu, 20 Jul 2017 16:03:23 +0800 Subject: clusters/main.py: Implement "_simulate_merger()" Simulate the formation history of each cluster and identify the last/recent major merger event. Also add new configuration option "tau_merger" and tweak several configurations options. Signed-off-by: Aaron LI --- fg21sim/configs/20-extragalactic.conf.spec | 28 ++++++---- fg21sim/extragalactic/clusters/main.py | 82 +++++++++++++++++++++++++++--- 2 files changed, 95 insertions(+), 15 deletions(-) diff --git a/fg21sim/configs/20-extragalactic.conf.spec b/fg21sim/configs/20-extragalactic.conf.spec index 377bd27..0f797a8 100644 --- a/fg21sim/configs/20-extragalactic.conf.spec +++ b/fg21sim/configs/20-extragalactic.conf.spec @@ -16,13 +16,31 @@ [extragalactic] - # Emissions from the clusters of galaxies + # Extended emissions from the clusters of galaxies + # The configurations in this ``[[clusters]]`` section may also be + # used by the following ``[[halos]]`` section. [[clusters]] # The clusters catalog derived from the Hubble Volume Project (CSV file) catalog = string(default=None) # Output the effective/inuse clusters catalog data (CSV file) catalog_outfile = string(default=None) + # Minimum mass change of the main cluster to be regarded as a merger + # event instead of an accretion event. + # Unit: [Msun] + merger_mass_min = float(default=1e12, min=1e10, max=1e14) + + # Mass ratio of the main and sub clusters, below which is regarded as + # a major merger event. + ratio_major = float(default=3.0, min=1.0, max=10.0) + + # The merger timescale, which roughly describes the duration of the + # merger-induced disturbance (~2-3 Gyr). This timescale is much longer + # the merger crossing time (~1 Gyr), and is also longer than the lifetime + # of radio halos. + # Unit: [Gyr] + tau_merger = float(default=3.0, min=1.0, max=5.0) + # The fraction that a cluster hosts a radio halo halo_fraction = float(default=None, min=0.0, max=1.0) @@ -51,14 +69,6 @@ # merger. (unit: Msun) merger_mass_th = float(default=1e13, min=1e12) - # Minimum mass change of the main-cluster to be regarded as a merger - # event rather than accretion. (unit: Msun) - merger_mass_min = float(default=1e12, min=1e10) - - # Mass ratio of the main and sub clusters, below which is regarded as - # a major merger event. - ratio_major = float(default=3.0, min=1.0, max=10.0) - # Radius of the giant radio halo in clusters (unit: kpc) # XXX: currently only support a constant radius of halos radius = float(default=500.0, min=100.0) diff --git a/fg21sim/extragalactic/clusters/main.py b/fg21sim/extragalactic/clusters/main.py index 501dc6a..c3a89d0 100644 --- a/fg21sim/extragalactic/clusters/main.py +++ b/fg21sim/extragalactic/clusters/main.py @@ -54,15 +54,15 @@ class GalaxyClusters: self.prefix = self.configs.getn(comp+"/prefix") self.save = self.configs.getn(comp+"/save") self.output_dir = self.configs.get_path(comp+"/output_dir") - if self.sky.type_ == "patch": - self.resolution = self.sky.pixelsize - else: - raise NotImplementedError("TODO: full-sky simulations") - # + self.merger_mass_min = self.configs.getn(comp+"/merger_mass_min") + self.ratio_major = self.configs.getn(comp+"/ratio_major") + self.tau_merger = self.configs.getn(comp+"/tau_merger") + self.filename_pattern = self.configs.getn("output/filename_pattern") self.use_float = self.configs.getn("output/use_float") self.checksum = self.configs.getn("output/checksum") self.clobber = self.configs.getn("output/clobber") + # Cosmology model self.H0 = self.configs.getn("cosmology/H0") self.OmegaM0 = self.configs.getn("cosmology/OmegaM0") @@ -70,7 +70,13 @@ class GalaxyClusters: self.sigma8 = self.configs.getn("cosmology/sigma8") self.cosmo = Cosmology(H0=self.H0, Om0=self.OmegaM0, Ob0=self.Omegab0, sigma8=self.sigma8) - # + + # Sky and resolution + if self.sky.type_ == "patch": + self.resolution = self.sky.pixelsize # [arcsec] + else: + raise NotImplementedError("TODO: full-sky simulations") + logger.info("Loaded and set up configurations") def _load_catalog(self): @@ -143,6 +149,70 @@ class GalaxyClusters: "rotation : ellipse rotation angle [deg]") logger.info("Added catalog column: rotation.") + def _simulate_merger(self): + """ + Simulate the *last/recent major merger* event for each cluster. + + First simulate the cluster formation history by tracing the + merger and accretion events of the main cluster, then identify + the last (i.e., most recent) major merger event according + to the mass ratio of two merging clusters. And the properties + of the found merger event are appended to the catalog. + + NOTE + ---- + There may be no such recent major merger event satisfying the + criteria, since we only tracing ``tau_merger`` (~3 Gyr) back. + On the other hand, the cluster may only experience minor merger + or accretion events. + + Catalog columns + --------------- + * ``lmm_mass1``, ``lmm_mass2`` : masses of the main and sub + clusters upon the last major merger event; unit: [Msun] + * ``lmm_z``, ``lmm_age`` : redshift and cosmic age (unit: [Gyr]) + of the last major merger event. + """ + logger.info("Simulating the galaxy formation to identify " + + "the last/recent major merger event ...") + num = len(self.catalog) + mdata = np.zeros(shape=(num, 4)) + num_major = 0 # number of clusters with recent major merger + + for i, row in zip(range(num), self.catalog.itertuples()): + ii = i + 1 + if ii % 50 == 0: + logger.info("[%d/%d] %.1f%% ..." % (ii, num, 100*ii/num)) + z0, M0 = row.z, row.mass + age0 = self.cosmo.age(z0) + zmax = self.cosmo.redshift(age0 - self.tau_merger) + clform = ClusterFormation(M0=M0, z0=z0, zmax=zmax, + ratio_major=self.ratio_major, + cosmo=self.cosmo, + merger_mass_min=self.merger_mass_min) + clform.simulate_mergertree(main_only=True) + mmev = clform.last_major_merger + if mmev: + num_major += 1 + mdata[i, :] = [mmev["M_main"], mmev["M_sub"], + mmev["z"], mmev["age"]] + else: + mdata[i, :] = [np.nan, np.nan, np.nan, np.nan] + + mdf = pd.DataFrame(data=mdata, + columns=["lmm_mass1", "lmm_mass2", + "lmm_z", "lmm_age"]) + self.catalog = self.catalog.join(mdf, how="outer") + self.catalog_comment += [ + "lmm_mass1 : main cluster mass at last major merger; [Msun]", + "lmm_mass2 : sub cluster mass at last major merger; [Msun]", + "lmm_z : redshift of the last major merger", + "lmm_age : cosmic age of the last major merger; [Gyr]", + ] + logger.info("Simulated and identified last major merger events.") + logger.info("%d (%.1f%%) clusters have recent major mergers." % + (num_major, 100*num_major/num)) + def postprocess(self): """ Do some necessary post-simulation operations. -- cgit v1.2.2