Two stellar-mass black holes in the globular cluster M22
Hundreds of stellar-mass black holes probably form in a typical globular star cluster, with all but one predicted to be ejected through dynamical interactions. Some observational support for this idea is provided by the lack of X-ray-emitting binary stars comprising one black hole and one other star...
| Main Authors: | , , , , |
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| Format: | Journal Article |
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Nature Publishing Group
2012
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| Online Access: | http://hdl.handle.net/20.500.11937/39444 |
| _version_ | 1848755592580038656 |
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| author | Strader, J. Chomiuk, L. Maccarone, T. Miller-Jones, James Seth, A. |
| author_facet | Strader, J. Chomiuk, L. Maccarone, T. Miller-Jones, James Seth, A. |
| author_sort | Strader, J. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Hundreds of stellar-mass black holes probably form in a typical globular star cluster, with all but one predicted to be ejected through dynamical interactions. Some observational support for this idea is provided by the lack of X-ray-emitting binary stars comprising one black hole and one other star (‘black-hole/X-ray binaries’) in Milky Way globular clusters, even though many neutron-star/X-ray binaries are known. Although a few black holes have been seen in globular clusters around other galaxies, the masses of these cannot be determined, and some may be intermediate-mass black holes that form through exotic mechanisms. Here we report the presence of two flat-spectrum radio sources in the Milky Way globular cluster M22, and we argue that these objects are black holes of stellar mass (each ~10–20 times more massive than the Sun) that are accreting matter. We find a high ratio of radio-to-X-ray flux for these black holes, consistent with the larger predicted masses of black holes in globular clusters compared to those outside. The identification of two black holes in one cluster shows that ejection of black holes is not as efficient as predicted by most models, and we argue that M22 may contain a total population of ~5–100 black holes. The large core radius of M22 could arise from heating produced by the black holes. |
| first_indexed | 2025-11-14T08:58:45Z |
| format | Journal Article |
| id | curtin-20.500.11937-39444 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:58:45Z |
| publishDate | 2012 |
| publisher | Nature Publishing Group |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-394442018-03-29T09:07:45Z Two stellar-mass black holes in the globular cluster M22 Strader, J. Chomiuk, L. Maccarone, T. Miller-Jones, James Seth, A. Astronomy Hundreds of stellar-mass black holes probably form in a typical globular star cluster, with all but one predicted to be ejected through dynamical interactions. Some observational support for this idea is provided by the lack of X-ray-emitting binary stars comprising one black hole and one other star (‘black-hole/X-ray binaries’) in Milky Way globular clusters, even though many neutron-star/X-ray binaries are known. Although a few black holes have been seen in globular clusters around other galaxies, the masses of these cannot be determined, and some may be intermediate-mass black holes that form through exotic mechanisms. Here we report the presence of two flat-spectrum radio sources in the Milky Way globular cluster M22, and we argue that these objects are black holes of stellar mass (each ~10–20 times more massive than the Sun) that are accreting matter. We find a high ratio of radio-to-X-ray flux for these black holes, consistent with the larger predicted masses of black holes in globular clusters compared to those outside. The identification of two black holes in one cluster shows that ejection of black holes is not as efficient as predicted by most models, and we argue that M22 may contain a total population of ~5–100 black holes. The large core radius of M22 could arise from heating produced by the black holes. 2012 Journal Article http://hdl.handle.net/20.500.11937/39444 10.1038/nature11490 Nature Publishing Group restricted |
| spellingShingle | Astronomy Strader, J. Chomiuk, L. Maccarone, T. Miller-Jones, James Seth, A. Two stellar-mass black holes in the globular cluster M22 |
| title | Two stellar-mass black holes in the globular cluster M22 |
| title_full | Two stellar-mass black holes in the globular cluster M22 |
| title_fullStr | Two stellar-mass black holes in the globular cluster M22 |
| title_full_unstemmed | Two stellar-mass black holes in the globular cluster M22 |
| title_short | Two stellar-mass black holes in the globular cluster M22 |
| title_sort | two stellar-mass black holes in the globular cluster m22 |
| topic | Astronomy |
| url | http://hdl.handle.net/20.500.11937/39444 |