| 研究実績の概要 |
1) We discovered a massive molecular outflow carrying 75% of the gas in the central region of galaxy B2 0258+35. The outflow coincides spatially with a radio jet, the energy source. The data confirms predictions of our simulations that low-power jets can drive such outflows and affect nuclear gas reservoirs, a vital mechanism for the co-evolution of black holes and galaxies. (Murthy, S., Morganti, R., Wagner, A. Y. et al. 2022, Nature Astronomy, 6, 488).
2) We constructed the first models of the putative Milky Way AGN jet that inflated the FERMI bubbles that reproduce the new MeerKAT radio data and eROSITA X-ray data of the Milky Way. The results provide predictions for the spin of the supermassive black hole of our galaxy (Sgr A*), inferred from recent Event Horizon Telescope observations (G. N. Cecil, A. Y. Wagner, et al. 2021, ApJ, 922, 2).
3) We established how AGN jet driven turbulence in gas-rich disc galaxies modify the star-formation rate in the disc. We applied the statistical theory of star-formation to the turbulent discs of our simulated radio-galaxies and found that the effect of the modification of turbulence by the jets on star formation is complicated but non-negligible. Depending on the orientation of the jet, star-formation can be slightly suppressed or slightly enhanced compared to the case without jets. This is the first quantitative study of feedback by AGN-driven turbulence, which may prove to be a new mode of AGN feedback, important in the majority of intermediate and low-mass galaxies (Mandal, A. et al, incl. Wagner, A. Y., 2021, MNRAS, 508, 4, 4738.)
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
While productivity has been high and some collaborations have progressed smoothly, the work on *magneto*-hydrodynamic jet-induced turbulence simulations, the last major step planned in the original proposal, have not yet been performed, mainly due to the inability to visit collaborators in Australia, India, and Paris in order to work out the details of these complicated simulations. We currently envisage the simulations to be complete by the end of September this year. If border restrictions permit, collaboration visits will be made before this time. The other reason this final step of the project proceeded slower than anticipated has been the lack of a Master or PhD student available to the PI.
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| 今後の研究の推進方策 |
The main objective for the next year of this grant is to complete the magneto hydrodynamical simulations of AGN jet induced turbulence in gas-rich disc galaxies. The analysis to be performed on the results of these simulations will be similar to those we performed in our we published in 2021 and will investigate the evolution of the gas properties and staff information rate in the Galaxy as a result of stirring and compression by the jet. The successful completion of the simulations contains two main challenges, one is to initialize and relax the magnetic field in the galaxy and one is to inject magnetic fields in with the jet. The first challenge has mostly been overcome, but the second challenge requires further investigating and testing. The timeline for this last step in the project is as follows:
2022/04-07: Complete setup for the initialization and injection of magnetic fields
2022/08: Perform magneto-hydrodynamic simulations complementary to the purely hydrodynamic ones. Parameters include jet power and jet inclination.
2022/09-12: Analyze simulation output for dependence of star-formation on parameters and summarize into a paper. Collaboration visits to Australia, India, and Paris, if possible.
2022/01-03: Present results at national and international conferences, including the Astronomical Society of Japan.
In parallel we shall conduct simulations of jets of various internal Mach numbers propagating into the ISM of a proto-galaxy in order to establish the effect of jet-driven turbulence in galaxies in the distant universe that are still forming.
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| 次年度使用額が生じた理由 |
The main reason for incurring rollover funds is the cancellation of the in-person attendance of international conferences and collaboration visits to Canberra and Paris due to the coronavirus pandemic and the related travel restrictions imposed by the Ministry of Foreign Affairs.
Main usage during the final year is travel to visit domestic and international collaborators and work with them to complete the complicated simulation setups required for the last part of this project. The three main destinations for collaboration are: 1) the ANU (RSAA) Canberra, Australia to work with Geoffrey Bicknell on the magnetic jet plasma 2) IUCAA Pune, India, to work with Dipanjan Mukherjee on the general setup of the magnetized galactic discs and 3) IAP Paris, France, to engage in discussions with Yohan Dubois, Joseph Silk, and Matt Lehnert, and on the importance of AGN-driven turbulence-regulated star-formation in galaxy populations. Border restrictions permitting, I shall conduct at most 2 out of the 3 travels during the summer months. After September, usage of the grant will consist mainly of travel to as many domestic and international conferences as possible.
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