Runaway and Hypervelocity Stars from Compact Object Encounters in Globular Clusters
The dense environments in the cores of globular clusters (GCs) facilitate many strong dynamical encounters among stellar objects. These encounters have been shown to be capable of ejecting stars from the host GC, whereupon they become runaway stars, or hypervelocity stars (HVSs) if unbound to the ga...
| 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 |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/acdc22 |
| _version_ | 1797303139432398848 |
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| author | Tomás Cabrera Carl L. Rodriguez |
| author_facet | Tomás Cabrera Carl L. Rodriguez |
| author_sort | Tomás Cabrera |
| collection | DOAJ |
| description | The dense environments in the cores of globular clusters (GCs) facilitate many strong dynamical encounters among stellar objects. These encounters have been shown to be capable of ejecting stars from the host GC, whereupon they become runaway stars, or hypervelocity stars (HVSs) if unbound to the galactic potential. We study high-speed stellar ejecta originating from GCs by using Monte Carlo N -body models, in particular focusing on binary–single encounters involving compact objects. We pair our model-discriminated populations with observational catalogs of Milky Way GCs (MWGCs) to compose a present-day Galactic population of stellar ejecta. We find that these kinds of encounters can accelerate stars to velocities in excess of 2000 km s ^−1 , to speeds beyond the previously predicted limits for ejecta from star-only encounters and in the same regime of Galactic center ejections. However, the same ejections can only account for 1.5%–20% of the total population of stellar runaways, and only 0.0001%–1% of HVS, with similar relative rates found for runaway white dwarfs. We also provide credible regions for ejecta from 149 MWGCs, which we hope will be useful as supplementary evidence when pairing runaway stars with origin GCs. |
| first_indexed | 2024-03-07T23:48:38Z |
| format | Article |
| id | doaj.art-e50bed8287f74ab4ac259c737468dcb1 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-07T23:48:38Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-e50bed8287f74ab4ac259c737468dcb12024-02-19T09:25:40ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0195311910.3847/1538-4357/acdc22Runaway and Hypervelocity Stars from Compact Object Encounters in Globular ClustersTomás Cabrera0https://orcid.org/0000-0002-1270-7666Carl L. Rodriguez1https://orcid.org/0000-0003-4175-8881McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University , 5000 Forbes Avenue, Pittsburgh, PA 15213, USAMcWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University , 5000 Forbes Avenue, Pittsburgh, PA 15213, USA; Department of Physics and Astronomy, University of North Carolina at Chapel Hill , 120 E. Cameron Avenue, Chapel Hill, NC 27599, USAThe dense environments in the cores of globular clusters (GCs) facilitate many strong dynamical encounters among stellar objects. These encounters have been shown to be capable of ejecting stars from the host GC, whereupon they become runaway stars, or hypervelocity stars (HVSs) if unbound to the galactic potential. We study high-speed stellar ejecta originating from GCs by using Monte Carlo N -body models, in particular focusing on binary–single encounters involving compact objects. We pair our model-discriminated populations with observational catalogs of Milky Way GCs (MWGCs) to compose a present-day Galactic population of stellar ejecta. We find that these kinds of encounters can accelerate stars to velocities in excess of 2000 km s ^−1 , to speeds beyond the previously predicted limits for ejecta from star-only encounters and in the same regime of Galactic center ejections. However, the same ejections can only account for 1.5%–20% of the total population of stellar runaways, and only 0.0001%–1% of HVS, with similar relative rates found for runaway white dwarfs. We also provide credible regions for ejecta from 149 MWGCs, which we hope will be useful as supplementary evidence when pairing runaway stars with origin GCs.https://doi.org/10.3847/1538-4357/acdc22Globular star clustersRunaway starsHypervelocity starsStellar dynamics |
| spellingShingle | Tomás Cabrera Carl L. Rodriguez Runaway and Hypervelocity Stars from Compact Object Encounters in Globular Clusters The Astrophysical Journal Globular star clusters Runaway stars Hypervelocity stars Stellar dynamics |
| title | Runaway and Hypervelocity Stars from Compact Object Encounters in Globular Clusters |
| title_full | Runaway and Hypervelocity Stars from Compact Object Encounters in Globular Clusters |
| title_fullStr | Runaway and Hypervelocity Stars from Compact Object Encounters in Globular Clusters |
| title_full_unstemmed | Runaway and Hypervelocity Stars from Compact Object Encounters in Globular Clusters |
| title_short | Runaway and Hypervelocity Stars from Compact Object Encounters in Globular Clusters |
| title_sort | runaway and hypervelocity stars from compact object encounters in globular clusters |
| topic | Globular star clusters Runaway stars Hypervelocity stars Stellar dynamics |
| url | https://doi.org/10.3847/1538-4357/acdc22 |
| work_keys_str_mv | AT tomascabrera runawayandhypervelocitystarsfromcompactobjectencountersinglobularclusters AT carllrodriguez runawayandhypervelocitystarsfromcompactobjectencountersinglobularclusters |