How many black holes are there in milky way
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Estimating the Number of Black Holes in the Milky Way
Overview of Black Hole Population in the Milky Way
The Milky Way galaxy is home to a vast number of black holes, both isolated and in binary systems. Recent studies have provided detailed estimates and models to understand the distribution and characteristics of these black holes.
Total Number of Black Holes
Recent synthetic models estimate that the Milky Way contains approximately 1.2 × 10^8 single black holes and about 9.3 × 10^6 black holes in binary systems1. These estimates are based on advanced population synthesis codes and models of star formation history and chemical evolution.
Black Holes in Globular Clusters
Globular clusters within the Milky Way also host black holes. For instance, the globular cluster M22 is estimated to contain between 5 and 100 black holes2 3 4. These black holes are often retained in the cluster due to dynamical interactions, although many are ejected over time.
Intermediate-Mass Black Holes
The Milky Way is also believed to contain a significant number of intermediate-mass black holes (IMBHs). Estimates suggest there could be between 1,000 and 10,000 IMBHs, each with masses ranging from 100 to 1,000 times that of the Sun5 6. These IMBHs are often enshrouded by dense dark minihalos, making them difficult to detect.
Binary Black Hole Systems
Binary black holes are a crucial aspect of the Milky Way's black hole population. Cosmological simulations predict that there are about 1.2 million binary black holes in the Milky Way, with a mean mass of 28 solar masses7. These systems provide valuable insights into binary evolution and the dynamics of massive stars.
Isolated Black Holes
Isolated black holes, which are not part of binary systems, are also prevalent in the Milky Way. Estimates suggest there are between 10^8 and 10^9 isolated stellar-mass black holes in our galaxy8 10. These black holes can sometimes be detected through their X-ray emissions as they accrete matter from the interstellar medium.
Conclusion
In summary, the Milky Way is home to a vast and diverse population of black holes. Current estimates suggest there are over 100 million black holes, including single black holes, binary systems, and intermediate-mass black holes. These findings are crucial for understanding the evolution of stars and the dynamics of our galaxy.
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Most relevant research papers on this topic
Synthetic catalog of black holes in the Milky Way
The Milky Way contains about 1.2 108 single black holes with an average mass of 14 M, and 9.3 106 BHs in binary systems with an average mass of 19 M, with metallicity significantly affecting black hole mass through stellar winds.
Multiple stellar-mass black holes in globular clusters: theoretical confirmation
Multiple stellar-mass black holes can be present in Milky Way clusters with extended core radiuses, as confirmed by the recent discovery of M22 black holes.
Highly CitedTwo stellar-mass black holes in the globular cluster M22
Two radio sources in the Milky Way globular cluster M22 are likely black holes of stellar mass, suggesting a population of 5–100 black holes in the cluster and potentially heating the core.
Highly CitedDark minihalos with intermediate mass black holes.
The Milky Way contains 10(3)-10(4) intermediate mass black holes, some of which are enshrouded by dense dark minispikes and minihalos, making their pointlike neutralino annihilation signals visible above the background.
A Search for Wandering Black Holes in the Milky Way with Gaia and DECaLS
Gaia and DECaLS have not found any "hypercompact" star clusters bound to intermediate-mass black holes in the Milky Way, suggesting no expected wandering intermediate-mass black holes.
Predicting the binary black hole population of the Milky Way with cosmological simulations
The Milky Way has 1.2 106 binary black holes, with 7 105 merged, and their mass distribution is compatible with LIGO/Virgo detections.
X-rays from isolated black holes in the Milky Way
Isolated black holes in the Milky Way can be detected with X-ray surveys, potentially revealing their mass estimates for microlensing black hole candidates.
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