Add nuclear star cluster component

.github/workflows/cicd.yml

@@ -1202,7 +1202,8 @@ jobs:
       fail-fast: false
       matrix:
         file: [ testSuite/parameters/mergerTreeEvolverThreaded.xml,
-                testSuite/parameters/constrainedMilkyWay.xml ]
+                testSuite/parameters/constrainedMilkyWay.xml,
+                testSuite/parameters/test-nuclear-star-cluster.xml ]
     uses: ./.github/workflows/testModel.yml
     with:
       file: ${{ matrix.file }}

.gitignore

@@ -52,3 +52,4 @@ doc/GalacticusAccented.bib
 source/FFTlog
 source/texfrag
 __pycache__
+.DS_Store

doc/Galacticus.bib

@@ -186,6 +186,25 @@ @article{angulo_fate_2009
 	pages = {983--995}
 },
 
+@article{antonini_coevolution_2015,
+	title = {The {Coevolution} of {Nuclear} {Star} {Clusters}, {Massive} {Black} {Holes}, and {Their} {Host} {Galaxies}},
+	volume = {812},
+	issn = {0004-637X},
+	url = {https://ui.adsabs.harvard.edu/abs/2015ApJ...812...72A},
+	doi = {10.1088/0004-637X/812/1/72},
+	abstract = {Studying how nuclear star clusters (NSCs) form and how they are related to the growth of the central massive black holes (MBHs) and their host galaxies is fundamental for our understanding of the evolution of galaxies and the processes that have shaped their central structures. We present the results of a semi-analytical galaxy formation model that follows the evolution of dark matter halos along merger trees, as well as that of the baryonic components. This model allows us to study the evolution of NSCs in a cosmological context, by taking into account the growth of NSCs due to both dynamical-friction-driven migration of stellar clusters and star formation triggered by infalling gas, while also accounting for dynamical heating from (binary) MBHs. We find that in situ star formation contributes a significant fraction (up to ∼80\%) of the total mass of NSCs in our model. Both NSC growth through in situ star formation and that through star cluster migration are found to generate NSC—host galaxy scaling correlations that are shallower than the same correlations for MBHs. We explore the role of galaxy mergers on the evolution of NSCs and show that observational data on NSC—host galaxy scaling relations provide evidence of partial erosion of NSCs by MBH binaries in luminous galaxies. We show that this observational feature is reproduced by our models, and we make predictions about the NSC and MBH occupation fraction in galaxies. We conclude by discussing several implications for theories of NSC formation.},
+	urldate = {2025-02-04},
+	journal = {The Astrophysical Journal},
+	author = {Antonini, Fabio and Barausse, Enrico and Silk, Joseph},
+	month = oct,
+	year = {2015},
+	note = {Publisher: IOP
+ADS Bibcode: 2015ApJ...812...72A},
+	keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, galaxies: evolution, galaxies: formation, galaxies: nuclei, Galaxy: center, General Relativity and Quantum Cosmology, quasars: supermassive black holes},
+	pages = {72},
+	file = {Accepted Version:/home/abensonca/.mozilla/firefox/f54gqgdx.default/zotero/storage/A3A9F684/Antonini et al. - 2015 - The Coevolution of Nuclear Star Clusters, Massive .pdf:application/pdf},
+}
+
 @article{arnaud_updated_1985,
 	title = {An updated evaluation of recombination and ionization rates},
 	volume = {60},
@@ -2423,6 +2442,25 @@ @article{eisenstein_power_1999
 	pages = {5--15}
 },
 
+@article{escala_observational_2021,
+	title = {Observational {Support} for {Massive} {Black} {Hole} {Formation} {Driven} by {Runaway} {Stellar} {Collisions} in {Galactic} {Nuclei}},
+	volume = {908},
+	issn = {0004-637X},
+	url = {https://ui.adsabs.harvard.edu/abs/2021ApJ...908...57E},
+	doi = {10.3847/1538-4357/abd93c},
+	abstract = {We explore a scenario for massive black hole formation driven by stellar collisions in galactic nuclei, proposing a new formation regime of global instability in nuclear stellar clusters triggered by runaway stellar collisions. Using order-of-magnitude estimations, we show that observed nuclear stellar clusters avoid the regime where stellar collisions are dynamically relevant over the whole system, while resolved detections of massive black holes are well into such collision-dominated regimes. We interpret this result in terms of massive black holes and nuclear stellar clusters being different evolutionary paths of a common formation mechanism, unified under the standard terminology of both being central massive objects. We propose a formation scenario where central massive objects more massive than ∼108 M⊙, which also have relaxation times longer that their collision times, will be too dense (in virial equilibrium) to be globally stable against stellar collisions, and most of the mass will collapse toward the formation of a massive black hole. Contrarily, this will only be the case at the core of less dense central massive objects, leading to the formation of black holes with much lower black hole efficiencies \$\{{\textbackslash}epsilon \}\_\{{\textbackslash}mathrm\{BH\}\}={\textbackslash}tfrac\{\{M\}\_\{{\textbackslash}mathrm\{BH\}\}\}\{\{M\}\_\{{\textbackslash}mathrm\{CMO\}\}\}\$ , with these efficiencies ɛBH drastically growing for central massive objects more massive than ∼107 M⊙, approaching unity around MCMO ∼ 108 M⊙. We show that the proposed scenario successfully explains the relative trends observed in the masses, efficiencies, and scaling relations between massive black holes and nuclear stellar clusters.},
+	urldate = {2025-02-04},
+	journal = {The Astrophysical Journal},
+	author = {Escala, Andrés},
+	month = feb,
+	year = {2021},
+	note = {Publisher: IOP
+ADS Bibcode: 2021ApJ...908...57E},
+	keywords = {1394, 1567, 1663, 2031, 2065, Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Collision processes, General Relativity and Quantum Cosmology, Relaxation time, Scaling relations, Star clusters, Supermassive black holes},
+	pages = {57},
+	file = {Full Text PDF:/home/abensonca/.mozilla/firefox/f54gqgdx.default/zotero/storage/KKILKQYL/Escala - 2021 - Observational Support for Massive Black Hole Forma.pdf:application/pdf},
+}
+
 @article{fakhouri_environmental_2009,
 	title = {Environmental dependence of dark matter halo growth - {I}. {Halo} merger rates},
 	volume = {394},
@@ -7803,6 +7841,26 @@ @article{van_meter_general_2010
 	keywords = {Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology}
 },
 
+@article{vergara_global_2023,
+	title = {Global instability by runaway collisions in nuclear stellar clusters: numerical tests of a route for massive black hole formation},
+	volume = {522},
+	issn = {0035-8711},
+	shorttitle = {Global instability by runaway collisions in nuclear stellar clusters},
+	url = {https://ui.adsabs.harvard.edu/abs/2023MNRAS.522.4224V},
+	doi = {10.1093/mnras/stad1253},
+	abstract = {The centres of galaxies host nuclear stellar clusters, supermassive black holes, or both. The origin of this dichotomy is still a mystery. Nuclear stellar clusters are the densest stellar system in the Universe, so they are ideal places for runaway collisions to occur. Previous studies have proposed the possible existence of a critical mass scale in such clusters, for which the occurrence of collisions becomes very frequent and leads to the formation of a very massive object. While it is difficult to directly probe this scenario with simulations, we here aim for a proof of concept using toy models where the occurrence of such a transition is shown based on simplified compact systems, where the typical evolution time-scales will be faster compared to the real Universe. Indeed our simulations confirm that such a transition takes place and that up to 50 per cent of the cluster mass can go into the formation of a central massive object for clusters that are above the critical mass scale. Our results thus support the proposed new scenario on the basis of idealized simulations. A preliminary analysis of observed nuclear star clusters shows similar trends related to the critical mass as in our simulations. We further discuss the caveats for the application of the proposed scenario in real nuclear star clusters.},
+	urldate = {2025-02-04},
+	journal = {Monthly Notices of the Royal Astronomical Society},
+	author = {Vergara, M. C. and Escala, A. and Schleicher, D. R. G. and Reinoso, B.},
+	month = jul,
+	year = {2023},
+	note = {Publisher: OUP
+ADS Bibcode: 2023MNRAS.522.4224V},
+	keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics, methods: numerical, stars: black hole, stars: kinematics and dynamics},
+	pages = {4224--4237},
+	file = {Full Text PDF:/home/abensonca/.mozilla/firefox/f54gqgdx.default/zotero/storage/6AFGN62Q/Vergara et al. - 2023 - Global instability by runaway collisions in nuclea.pdf:application/pdf},
+}
+
 @article{verner_analytic_1995,
 	title = {Analytic {FITS} for partial photoionization cross sections.},
 	volume = {109},

doc/Glossary.tex

@@ -27,6 +27,7 @@
 \newglossaryentry{cdf}{type=\acronymtype, name={CDF}, description=\glslink{cdfg}{cumulative distribution function}, first={cumulative distribution function (CDF)}, firstplural={cumulative distribution functions (CDFs)}}
 \newglossaryentry{gsl}{type=\acronymtype, name={GSL}, description=\glslink{gslg}{GNU Scientific Library}, first={GNU Scientific Library (GSL)}}
 \newglossaryentry{gama}{type=\acronymtype, name={GAMA}, description=\glslink{gamag}{Galaxy and Mass Assembly}, first={Galaxy and Mass Assembly (GAMA)}}
+\newglossaryentry{nsc}{type=\acronymtype, name={NSC}, description=\glslink{nscg}{nuclear star cluster}, first={nuclear star cluster (NSC)}, firstplural={nuclear star clusters (NSC)}}
 
 % Glossary entries.
 \newglossaryentry{FFTLog}{name={FFTLog}, description={\href{https://jila.colorado.edu/~ajsh/FFTLog/index.html}{FFTLog} is a code to compute fast Fourier transforms of discrete periodic sequences of logarithmically spaced data}}
@@ -96,6 +97,9 @@
 \newglossaryentry{fdmg}{name={FDM},
     description={\href{https://en.wikipedia.org/wiki/Fuzzy_cold_dark_matter}{Fuzzy dark matter} (FDM) is a hypothesized type of dark matter consisting of extremely light scalar particles with masses on the order of $10^{-22}$~eV}}
 
+\newglossaryentry{nscg}{name={NSC},
+    description={\href{https://en.wikipedia.org/wiki/Nuclear_star_cluster}{Nuclear star clusters} (NSC) are high-density star clusters found in the centers of some galaxies}}
+
 \newglossaryentry{wdmg}{name={WDM},
     description={\href{http://en.wikipedia.org/wiki/Warm_dark_matter}{Warm dark matter} (WDM) is a hypothesized type of dark matter in which the particle has non-negligible thermal velocity at decoupling}}
 

source/accretion_disks.spectra.file.F90

@@ -173,13 +173,15 @@ double precision function fileSpectrumNode(self,node,wavelength)
     type            (treeNode                ), intent(inout)  :: node
     double precision                          , intent(in   )  :: wavelength
     class           (nodeComponentBlackHole  ), pointer        :: blackHole
-    double precision                                           :: rateAccretionSpheroid, rateAccretionHotHalo, &
-         &                                                        rateAccretion        , efficiencyRadiative
+    double precision                                           :: rateAccretionSpheroid, rateAccretionHotHalo           , &
+         &                                                        rateAccretion        , rateAccretionNuclearStarCluster, &
+         &                                                        efficiencyRadiative
 
     blackHole => node%blackHole()
-    call self%blackHoleAccretionRate_%rateAccretion(blackHole,rateAccretionSpheroid,rateAccretionHotHalo)
+    call self%blackHoleAccretionRate_%rateAccretion(blackHole,rateAccretionSpheroid,rateAccretionHotHalo,rateAccretionNuclearStarCluster)
     rateAccretion      =+                    rateAccretionSpheroid                                                         &
-         &              +                    rateAccretionHotHalo
+         &              +                    rateAccretionHotHalo                                                          &
+         &              +                    rateAccretionNuclearStarCluster
     efficiencyRadiative=self%accretionDisks_%efficiencyRadiative  (blackHole,rateAccretion                               )
     fileSpectrumNode   =self                %spectrum             (          rateAccretion,efficiencyRadiative,wavelength)
     return

source/black_holes.CGM_heating.jet_power.F90

@@ -122,13 +122,14 @@ double precision function jetPowerHeatingRate(self,blackHole) result(rateHeating
     implicit none
     class           (blackHoleCGMHeatingJetPower), intent(inout) :: self
     class           (nodeComponentBlackHole     ), intent(inout) :: blackHole
-    double precision                                             :: rateAccretionSpheroid, rateAccretionHotHalo, &
-         &                                                          rateACcretion
+    double precision                                             :: rateAccretionSpheroid          , rateAccretionHotHalo, &
+         &                                                          rateAccretionNuclearStarCluster, rateAccretion
 
     ! Compute the jet power and CGM heating rate.
-    call self%blackHoleAccretionRate_%rateAccretion(blackHole,rateAccretionSpheroid,rateAccretionHotHalo)
-    rateAccretion=+rateAccretionSpheroid &
-         &        +rateAccretionHotHalo
+    call self%blackHoleAccretionRate_%rateAccretion(blackHole,rateAccretionSpheroid,rateAccretionHotHalo,rateAccretionNuclearStarCluster)
+    rateAccretion=+rateAccretionSpheroid           &
+         &        +rateAccretionHotHalo            &
+         &        +rateAccretionNuclearStarCluster
     rateHeating  =+self                %efficiencyRadioMode                          &
          &        *self%accretionDisks_%powerJet           (blackHole,rateAccretion)
     return

source/black_holes.CGM_heating.quasistatic.F90

@@ -133,14 +133,16 @@ double precision function quasistaticHeatingRate(self,blackHole) result(rateHeat
     class           (nodeComponentBlackHole        ), intent(inout) :: blackHole
     double precision                                , parameter     :: radiusCoolingFractionalTransitionMinimum=0.9d0
     double precision                                , parameter     :: radiusCoolingFractionalTransitionMaximum=1.0d0
-    double precision                                                :: rateAccretionSpheroid                         , rateAccretionHotHalo   , &
-         &                                                             rateAccretion                                 , radiusCoolingFractional, &
-         &                                                             efficiencyCoupling                            , x
+    double precision                                                :: rateAccretionSpheroid                         , rateAccretionHotHalo           , &
+         &                                                             rateAccretion                                 , rateAccretionNuclearStarCluster, &
+         &                                                             efficiencyCoupling                            , x                              , &
+         &                                                             radiusCoolingFractional
 
     ! Compute accretion rate onto the black hole.
-    call self%blackHoleAccretionRate_%rateAccretion(blackHole,rateAccretionSpheroid,rateAccretionHotHalo)
-    rateAccretion=+rateAccretionSpheroid &
-         &        +rateAccretionHotHalo
+    call self%blackHoleAccretionRate_%rateAccretion(blackHole,rateAccretionSpheroid,rateAccretionHotHalo,rateAccretionNuclearStarCluster)
+    rateAccretion=+rateAccretionSpheroid           &
+         &        +rateAccretionHotHalo            &
+         &        +rateAccretionNuclearStarCluster
     ! No heating for non-positive accretion rates.
     if (rateAccretion > 0.0d0) then
        ! Compute coupling efficiency based on whether halo is cooling quasistatically.

source/black_holes.accretion_rates.F90

@@ -41,8 +41,8 @@ module Black_Hole_Accretion_Rates
     <description>Computes the mass accretion rate onto a black hole.</description>
     <type>void</type>
     <pass>yes</pass>
-    <argument>class           (nodeComponentBlackHole), intent(inout) :: blackHole                                          </argument>
-    <argument>double precision                        , intent(  out) :: rateMassAccretionSpheroid, rateMassAccretionHotHalo</argument>
+    <argument>class           (nodeComponentBlackHole), intent(inout) :: blackHole                                                                               </argument>
+    <argument>double precision                        , intent(  out) :: rateMassAccretionSpheroid, rateMassAccretionHotHalo, rateMassAccretionNuclearStarCluster</argument>
    </method>
   </functionClass>
   !!]

source/black_holes.accretion_rates.spheroid_tracking.F90

@@ -41,7 +41,7 @@
      final     ::                  spheroidTrackingDestructor
      procedure :: rateAccretion => spheroidTrackingRateAccretion
   end type blackHoleAccretionRateSpheroidTracking
-  
+
   interface blackHoleAccretionRateSpheroidTracking
      !!{
      Constructors for the {\normalfont \ttfamily spheroidTracking} black hole accretion rate class.
@@ -62,7 +62,7 @@ function spheroidTrackingConstructorParameters(parameters) result(self)
     type            (inputParameters                       ), intent(inout) :: parameters
     class           (starFormationRateSpheroidsClass       ), pointer       :: starFormationRateSpheroids_
     double precision                                                        :: growthRatioToStellarSpheroid
-    
+
     !![
     <inputParameter>
       <name>growthRatioToStellarSpheroid</name>
@@ -101,27 +101,29 @@ subroutine spheroidTrackingDestructor(self)
     !!}
     implicit none
     type(blackHoleAccretionRateSpheroidTracking), intent(inout) :: self
-    
+
     !![
     <objectDestructor name="self%starFormationRateSpheroids_"/>
     !!]                                                                                                                                                                                                               
     return
   end subroutine spheroidTrackingDestructor
-  
-  subroutine spheroidTrackingRateAccretion(self,blackHole,rateMassAccretionSpheroid,rateMassAccretionHotHalo)
+
+  subroutine spheroidTrackingRateAccretion(self,blackHole,rateMassAccretionSpheroid,rateMassAccretionHotHalo,rateMassAccretionNuclearStarCluster)
     !!{
     Compute the accretion rate onto a black hole.
     !!}
     use :: Galacticus_Nodes, only : treeNode
     implicit none
     class           (blackHoleAccretionRateSpheroidTracking), intent(inout) :: self
     class           (nodeComponentBlackHole                ), intent(inout) :: blackHole
-    double precision                                        , intent(  out) :: rateMassAccretionSpheroid,rateMassAccretionHotHalo
+    double precision                                        , intent(  out) :: rateMassAccretionSpheroid          , rateMassAccretionHotHalo, &
+         &                                                                     rateMassAccretionNuclearStarCluster
     type            (treeNode                              ), pointer       :: node
-
-    node                      =>  blackHole                            %host                        (    )
-    rateMassAccretionSpheroid =  +self                                 %growthRatioToStellarSpheroid       &
-         &                       *self     %starFormationRateSpheroids_%rate                        (node)
-    rateMassAccretionHotHalo  =  +0.0d0
+
+    node                                =>  blackHole                            %host                        (    )
+    rateMassAccretionSpheroid           =  +self                                 %growthRatioToStellarSpheroid       &
+         &                                 *self     %starFormationRateSpheroids_%rate                        (node)
+    rateMassAccretionHotHalo            =  +0.0d0
+    rateMassAccretionNuclearStarCluster =  +0.0d0
     return
   end subroutine spheroidTrackingRateAccretion