Impact of an Active Sgr A* on the Synthesis of Water and Organic Molecules Throughout the Milky Way

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 $4\times 10^6{M}_{\odot }$. 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 amount of hard X-rays that can penetrate the dense interstellar medium in the Galactic plane. Here we further study the impact of the 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 the X-ray irradiation could significantly enhance the abundances of these species. The effect is the most significant in those 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.

21 pages, 10 figures, accepted by ApJ

References in corpus (22)

• The mass distribution and gravitational potential of the Milky Way
• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• Cold Dark Clouds: The Initial Conditions for Star Formation
• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• Molecular line emission in NGC1068 imaged with ALMA. I An AGN-driven outflow in the dense molecular gas
• Diagnostics of irradiated dense gas in galaxy nuclei. II. A grid of XDR and PDR models
• Polycylcic Aromatic Hydrocarbons (PAH's) in dense cloud chemistry
• Quasars Are Not Light-Bulbs: Testing Models of Quasar Lifetimes with the Observed Eddington Ratio Distribution
• Molecular line emission in NGC1068 imaged with ALMA: II. The chemistry of the dense molecular gas
• Self-gravitating accretion disk in Sgr A* few million years ago: was Sgr A* a failed quasar?
• How realistic UV spectra and X-rays suppress the abundance of direct collapse black holes
• Multi-molecule ALMA observations towards the Seyfert 1 galaxy NGC 1097
• Distributions of molecules in the circumnuclear disk and surrounding starburst ring in the Seyfert galaxy NGC 1068 observed with ALMA
• Interstellar Simulations Using A Unified Microscopic-Macroscopic Monte Carlo Model with a full Gas-Grain Network including Bulk Diffusion in Ice Mantles
• ALMA Observations of Nearby Luminous Infrared Galaxies with Various AGN Energetic Contributions Using Dense Gas Tracers
• A Multi-Transition Study of Molecules toward NGC 1068 based on High-Resolution Imaging Observations with ALMA
• The habitability of the Milky Way during the active phase of its central supermassive black hole
• Active Galactic Nuclei: Boon or Bane for Biota?
• Dust charge distribution in the interstellar medium
• Revisiting the structure and spectrum of the magnetic-reconnection-heated corona in luminous AGNs
• Comparative analysis of the influence of Sgr A* and nearby active galactic nuclei on the mass loss of known exoplanets
• Sculpting the Stellar Cusp in the Galactic Center

Cited by in corpus (6)

• Photodissociation and X-Ray Dominated Regions
• Chemical modeling of the complex organic molecules in the extended region around Sagittarius B2
• The Impact of Tidal Disruption Events on Galactic Habitability
• The impact of AGN outflows on the surface habitability of terrestrial planets in the Milky Way
• Modelling cosmic masers in C-type shock waves -- the coexistence of Class I CH3OH and 1720 MHz OH masers
• On the relative importance of AGN winds for the evolution of exoplanet atmospheres