Distinguishing Dark Matter Cusps from Cores Using Globular Clusters
Globular clusters (GCs) provide valuable insight into the properties of their host galaxies’ dark matter halos. Using N -body simulations incorporating semianalytic dynamical friction and GC−GC merger prescriptions, we study the evolution of GC radial distributions and mass functions in cuspy and co...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/accc2d |
| _version_ | 1797698695142047744 |
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| author | Shaunak Modak Shany Danieli Jenny E. Greene |
| author_facet | Shaunak Modak Shany Danieli Jenny E. Greene |
| author_sort | Shaunak Modak |
| collection | DOAJ |
| description | Globular clusters (GCs) provide valuable insight into the properties of their host galaxies’ dark matter halos. Using N -body simulations incorporating semianalytic dynamical friction and GC−GC merger prescriptions, we study the evolution of GC radial distributions and mass functions in cuspy and cored dark matter halos. Modeling the dynamics of the GC-rich system in the dwarf galaxy UGC 7369, we find that friction-induced inspiral and subsequent mergers of massive GCs can naturally and robustly explain the mass segregation of the GCs and the existence of a nuclear star cluster (NSC). However, the multiple mergers required to form the NSC only take place when the dark matter halo is cuspy. In a cored halo, stalling of the dynamical friction within the core halts the inspiral of the GCs, and so the GC merger rate falls significantly, precluding the formation of an NSC. We therefore argue that the presence of an NSC requires a cusp in UGC 7369. More generally, we propose that the presence of an NSC and the corresponding alteration of the GC mass function due to mergers may be used as an indicator of a cuspy halo for galaxies in which we expect NSC formation to be merger dominated. These observables represent a simple, powerful complement to other inner halo density profile constraint techniques and should allow for straightforward extension to larger samples. |
| first_indexed | 2024-03-12T03:57:47Z |
| format | Article |
| id | doaj.art-79a556853cbf40c483c144b1b3e57592 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:57:47Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-79a556853cbf40c483c144b1b3e575922023-09-03T11:46:24ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01950217810.3847/1538-4357/accc2dDistinguishing Dark Matter Cusps from Cores Using Globular ClustersShaunak Modak0https://orcid.org/0000-0002-8532-827XShany Danieli1https://orcid.org/0000-0002-1841-2252Jenny E. Greene2https://orcid.org/0000-0002-5612-3427Department of Astrophysical Sciences, 4 Ivy Lane, Princeton University , Princeton, NJ 08544, USA ; shaunakmodak@princeton.eduDepartment of Astrophysical Sciences, 4 Ivy Lane, Princeton University , Princeton, NJ 08544, USA ; shaunakmodak@princeton.eduDepartment of Astrophysical Sciences, 4 Ivy Lane, Princeton University , Princeton, NJ 08544, USA ; shaunakmodak@princeton.eduGlobular clusters (GCs) provide valuable insight into the properties of their host galaxies’ dark matter halos. Using N -body simulations incorporating semianalytic dynamical friction and GC−GC merger prescriptions, we study the evolution of GC radial distributions and mass functions in cuspy and cored dark matter halos. Modeling the dynamics of the GC-rich system in the dwarf galaxy UGC 7369, we find that friction-induced inspiral and subsequent mergers of massive GCs can naturally and robustly explain the mass segregation of the GCs and the existence of a nuclear star cluster (NSC). However, the multiple mergers required to form the NSC only take place when the dark matter halo is cuspy. In a cored halo, stalling of the dynamical friction within the core halts the inspiral of the GCs, and so the GC merger rate falls significantly, precluding the formation of an NSC. We therefore argue that the presence of an NSC requires a cusp in UGC 7369. More generally, we propose that the presence of an NSC and the corresponding alteration of the GC mass function due to mergers may be used as an indicator of a cuspy halo for galaxies in which we expect NSC formation to be merger dominated. These observables represent a simple, powerful complement to other inner halo density profile constraint techniques and should allow for straightforward extension to larger samples.https://doi.org/10.3847/1538-4357/accc2dGalaxy dark matter halosGlobular star clustersDynamical frictionDwarf galaxies |
| spellingShingle | Shaunak Modak Shany Danieli Jenny E. Greene Distinguishing Dark Matter Cusps from Cores Using Globular Clusters The Astrophysical Journal Galaxy dark matter halos Globular star clusters Dynamical friction Dwarf galaxies |
| title | Distinguishing Dark Matter Cusps from Cores Using Globular Clusters |
| title_full | Distinguishing Dark Matter Cusps from Cores Using Globular Clusters |
| title_fullStr | Distinguishing Dark Matter Cusps from Cores Using Globular Clusters |
| title_full_unstemmed | Distinguishing Dark Matter Cusps from Cores Using Globular Clusters |
| title_short | Distinguishing Dark Matter Cusps from Cores Using Globular Clusters |
| title_sort | distinguishing dark matter cusps from cores using globular clusters |
| topic | Galaxy dark matter halos Globular star clusters Dynamical friction Dwarf galaxies |
| url | https://doi.org/10.3847/1538-4357/accc2d |
| work_keys_str_mv | AT shaunakmodak distinguishingdarkmattercuspsfromcoresusingglobularclusters AT shanydanieli distinguishingdarkmattercuspsfromcoresusingglobularclusters AT jennyegreene distinguishingdarkmattercuspsfromcoresusingglobularclusters |