Title | Impact of an Active Sgr A* on the Synthesis of Water and Organic Molecules throughout the Milky Way |
Authors | Liu, Chang Chen, Xian Du, Fujun |
Affiliation | Peking Univ, Sch Phys, Dept Astron, Beijing 100871, Peoples R China Kavli Inst Astron & Astrophys, Beijing 100871, Peoples R China Chinese Acad Sci, Purple Mt Observ, Nanjing 210023, Peoples R China Chinese Acad Sci, Key Lab Radio Astron, Nanjing 210023, Peoples R China Univ Sci & Technol China, Sch Astron & Space Sci, Hefei 230026, Peoples R China |
Keywords | DENSE INTERSTELLAR CLOUDS SUPERMASSIVE BLACK-HOLES PHOTOELECTRIC-EMISSION GALACTIC-CENTER GAS CHEMISTRY MODELS DUST DIAGNOSTICS IONIZATION |
Issue Date | Aug-2020 |
Publisher | ASTROPHYSICAL JOURNAL |
Abstract | Sgr A*, the supermassive black hole (SMBH) in our Galaxy, is dormant today, but it should have gone through multiple gas-accretion episodes in the past billions of years to grow to its current mass of 4 x 10(6)M. Each episode temporarily ignites the SMBH and turns the Galactic Center into an active galactic nucleus (AGN). Recently, we showed that the AGN could produce large amounts of hard X-rays that can penetrate the dense interstellar medium in the Galactic plane. Here we further study the impact of X-rays on the molecular chemistry in our Galaxy. We use a chemical-reaction network to simulate the evolution of several molecular species, including H2O, CH3OH, and H2CO, both in the gas phase and on the surface of dust grains. We find that X-ray irradiation could significantly enhance the abundances of these species. The effect is most significant in young, high-density molecular clouds and could be prominent at a Galactic distance of 8 kpc or smaller. The imprint in the chemical abundance is visible even several million years after the AGN turns off. |
URI | http://hdl.handle.net/20.500.11897/591437 |
ISSN | 0004-637X |
DOI | 10.3847/1538-4357/aba758 |
Indexed | SCI(E) |
Appears in Collections: | 物理学院 |