Summary Primordial Black Holes and the Planet 9 Hypothesis arxiv.org
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Durham University and the University of Illinois suggest that "Planet 9" could potentially be a primordial black hole.
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Key Points
- A new study suggests that the mysterious "Planet 9" in our solar system may actually be a primordial black hole (PBH).
- The anomalous orbits of Trans-Neptunian Objects (TNOs) and an excess in microlensing events in the 5-year OGLE dataset could be explained by a population of PBHs.
- The probability of capturing a PBH by the Solar System is comparable to capturing a free-floating planet.
- A PBH surrounded by a dark matter microhalo could provide a potential detection signal through annihilation signals from the microhalo.
- PBHs can accrete dense dark matter microhalos, leading to enhanced dark matter annihilations and potentially detectable signals.
- Indirect detection methods and specific freeze-in models of dark matter production can be used to calculate bounds on the DM annihilation cross-section.
- Alternative explanations such as DM microhalos, exotic compact astrophysical bodies, or a toroidal DM mass distribution could also explain the observed anomalies.
- Dedicated searches for moving sources in high-energy cosmic rays are needed to further test the PBH hypothesis.
Summaries
17 word summary
Durham University and the University of Illinois propose that "Planet 9" may be a primordial black hole.
68 word summary
Researchers from Durham University and the University of Illinois suggest that the mysterious "Planet 9" in our solar system may actually be a primordial black hole (PBH). The study explores the probability of capturing a PBH versus a free-floating planet, discusses observational constraints, and considers the possibility of detecting the PBH through indirect methods. If conventional searches for Planet 9 fail, the PBH hypothesis becomes a compelling explanation.
137 word summary
A study by researchers from Durham University and the University of Illinois suggests that the mysterious "Planet 9" in our solar system may actually be a primordial black hole (PBH). The researchers propose that the unusual orbits of Trans-Neptunian Objects (TNOs) and an excess of microlensing events in the OGLE dataset could be explained by a population of PBHs. They explore the probability of capturing a PBH versus a free-floating planet by the Solar System, finding that the rates are similar. The study discusses observational constraints on a PBH in the outer Solar System and its implications for dark matter. It also considers the possibility of detecting the PBH through indirect detection methods. While alternative explanations are acknowledged, the researchers argue that if conventional searches for Planet 9 fail, the PBH hypothesis will become a compelling explanation.
394 word summary
A recent study conducted by researchers from Durham University and the University of Illinois at Chicago suggests that the mysterious "Planet 9" in our solar system may actually be a primordial black hole (PBH). The researchers propose that the unusual orbits of Trans-Neptunian Objects (TNOs) and an excess of microlensing events in the OGLE dataset could be explained by a population of PBHs with a mass several times that of Earth. They argue that if the microlensing events are caused by PBHs, it is possible that the orbital anomalies of TNOs are also due to a captured PBH.
The study explores the probability of capturing a PBH versus a free-floating planet by the Solar System. The researchers estimate the capture probability using the differential cross-section, velocity distribution, and local density of PBHs and free floaters. They find that the rates of capturing an Earth mass PBH and a free-floating planet are similar.
Observational constraints on a PBH in the outer Solar System are discussed, noting significant differences between planets and PBHs. The researchers highlight the potential detection signal from a PBH surrounded by a dark matter microhalo through annihilation signals.
The implications of a PBH in the outer Solar System for dark matter are also explored. The researchers argue that if the rest of the dark matter is accounted for by DM particles, PBHs can accrete dense dark matter microhalos, leading to enhanced dark matter annihilations and potentially detectable signals.
The study considers the possibility of detecting the PBH through indirect detection methods. A specific freeze-in model of dark matter production is analyzed, calculating photon flux and energy flux from DM annihilation. Bounds on the DM annihilation cross-section are derived and found to be satisfied in the specific freeze-in model considered.
Alternative explanations for the anomalies, such as DM microhalos, exotic compact astrophysical bodies, or a toroidal DM mass distribution, are acknowledged. However, these scenarios have distinct experimental signatures compared to a PBH or a planet.
In conclusion, the study proposes that the observed anomalies of TNOs and microlensing events could be explained by a population of PBHs. The researchers argue that if conventional searches for Planet 9 fail and evidence for TNO anomalies continues to grow, the PBH hypothesis will become a compelling explanation. They emphasize the need for dedicated searches for moving sources in high-energy cosmic rays to further test this hypothesis.
502 word summary
A new study suggests that the mysterious "Planet 9" in our solar system may actually be a primordial black hole (PBH). The study, conducted by researchers from the Institute for Particle Physics Phenomenology at Durham University and the University of Illinois at Chicago, proposes that the anomalous orbits of Trans-Neptunian Objects (TNOs) and an excess in microlensing events in the 5-year OGLE dataset could be explained by a population of PBHs with a mass several times that of Earth. The researchers argue that if the OGLE events are due to a population of PBHs, it is possible that the orbital anomalies of TNOs are also due to one of these PBHs that was captured by the Solar System.
The study suggests that the probability of capturing a PBH by the Solar System is comparable to capturing a free-floating planet. The researchers estimate the capture probability using the differential cross-section, velocity distribution, and local density of PBHs and free floaters. They find that the rates of capturing an Earth mass PBH and a free-floating planet are comparable.
The researchers also discuss the observational constraints on a PBH in the outer Solar System. They note that the observational constraints differ significantly between planets and PBHs. In particular, they highlight that a PBH surrounded by a dark matter microhalo could provide a potential detection signal through annihilation signals from the microhalo.
The study further explores the implications of a PBH in the outer Solar System for dark matter. The researchers discuss the formation of PBHs from density fluctuations in the early universe and their relation to dark matter. They argue that if the rest of the dark matter is accounted for by DM particles, PBHs can accrete dense dark matter microhalos. The high density of these microhalos can lead to enhanced dark matter annihilations, potentially resulting in detectable signals.
The researchers also discuss the possibility of detecting the PBH through indirect detection methods. They consider a specific freeze-in model of dark matter production and calculate the photon flux and energy flux from DM annihilation. They compare these fluxes to the smallest detectable fluxes in the 8-year Fermi-LAT source catalog and derive bounds on the DM annihilation cross-section. They find that for the specific freeze-in model considered, the bounds on the annihilation cross-section are satisfied.
Finally, the study acknowledges that alternative explanations, such as DM microhalos, exotic compact astrophysical bodies, or a toroidal DM mass distribution, could also explain the observed anomalies. However, each of these scenarios implies different experimental signatures that are distinct from those of a PBH or a planet.
In conclusion, the study proposes that the anomalous orbits of TNOs and microlensing events in the OGLE dataset could be explained by a population of PBHs. The researchers argue that if conventional searches fail to find Planet 9 and the evidence for TNO anomalies continues to grow, the PBH hypothesis will become a compelling explanation. They emphasize the need for dedicated searches for moving sources in high-energy cosmic rays to test this hypothesis further.