2022 Fiscal Year Research-status Report
Predicting the formation of stars, black holes, and gravitational-wave signals with young galaxy clusters
| Project/Area Number |
21K13911
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
ATA METIN 東京大学, カブリ数物連携宇宙研究機構, 客員准科学研究員 (60836229)
|
|---|
| Project Period (FY) |
2021-04-01 – 2024-03-31
|
| Keywords | Large-scale structures / Cosmological Simulations / Gravitational Waves / Balck holes |
|---|
| Outline of Annual Research Achievements |
In 2022 we published a Nature Astronomy (High Impact Journal) using the constrained simulations technique that I described in the proposal
M. Ata et al. Nature Astronomy 6 (2022) 857. This was a great success and showed that the method of 'constrained simulations' is capable reproducing observed structures and even model them into the future.
We were able to reproduce the observed structures within our simulations and also predict their future fate by moving the simulation until today. This resembles a predicted future fate of these structures by a total of 11 billion years. At the final time step we analyzed the resulting structures so that we were able to trace back all constituent dark matter particles that belong to this final collapsed object. This was the first application of a constrained simulations on a lightcone.
As stated in my proposal, I will use this technique to predict the creation of gravitational wave events. After a more thoroughly literature research, I came to the conclusion that a limited patch at high redshifts, like we analyzed in the 2022 paper, is not the ideal environment. Also, I re-elaborated the framework and found an application that is more suited to our constrained maps.
|
| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The publication of the Nature Astronomy paper was a great progress.
Additionally I have started on working to populate the simulations with gravitational wave sources. This is the next step of the project and needs careful handling on the merger rates of binary blackholes. The actual best way to do this would be using hydrodynamical simulation that naturally produce blackholes, at least up to the resolution that the simulation recovers.The advantage of our method lies in the ability to reproduce observed structures. Given the evolution of the custom initial conditions, we gain knowledge of the merger histories of individual structures. We will use this knowledge to model the fusion and merging of the central supermassive blackhole that are situated in the center of each galaxy.
|
| Strategy for Future Research Activity |
My original idea to use galaxy protoclusters is still a valuable project to understand star-formation in that redshift range, but it is not the ideal set-up to constrain the SGWB anisotropies, which I think is the most important effect that we should focus on. For that reason I decided to start a project on the the local Universe. At the moment I am reconstructing the Universe with a set of galaxy surveys that cover the the range of 0<z<0.7. Once these reconstructions are prepared I will apply hydrodynamical re-simulations to the inferred initial conditions. These simulations will resolve the central blackhole in the galaxies' centers. Applying a phenomenological merging rate for supermassive blackholes that are sufficiently close, we can predict the stochastic gravitational wave background from astrophysical sources. This will be very important in order to measure to cosmological part of the SGWB and study the early Universe, including theories of inflation and primordial black holes as dark matter candidates.
|
| Causes of Carryover |
A few trips were decreased last year due to the pandemic issue. This year, I plan to use the funds to travel abroad and visit to my collaboraters. This is necessary to discuss recent works of mine that are relevant for the upcoming PFS survey.
|
