The evolution of circumstellar discs in the Galactic Centre: an application to the G-clouds

Abstract

The Galactic Centre is known to have undergone a recent star formation episode a few Myrs ago, which likely produced many T Tauri stars hosting circumstellar discs. It has been suggested that these discs may be the compact and dusty ionized sources identified as ``G-clouds''. Given the Galactic Centre's hostile environment, we study the possible evolutionary pathways these discs experience. We compute new external photoevaporation models applicable to discs in the Galactic Centre that account for the sub-sonic launching of the wind and absorption of UV photons by dust. Using evolutionary disc calculations, we find that photoevaporation's rapid truncation of the disc causes them to accrete onto the central star rapidly. Ultimately, an accreting circumstellar disc has a lifetime $\lesssim 1$Myr, which would fail to live long enough to explain the G-clouds. However, we identify a new evolutionary pathway for circumstellar discs in the Galactic Centre. Removal of disc material by photoevaporation prevents the young star from spinning down due to magnetic braking, ultimately causing the rapidly spinning young star to torque the disc into a ``decretion disc'' state which prevents accretion. At the same time, any planetary companion in the disc will trap dust outside its orbit, shutting down photoevaporation. The disc can survive for up to $\sim$10 Myr in this state. Encounters with other stars are likely to remove the planet on Myr timescales, causing photoevaporation to restart, giving rise to a G-cloud signature. A giant planet fraction of $\sim 10\%$ can explain the number of observed G-clouds.

Accepted for publication in MNRAS

References in corpus (46)

• Modules for Experiments in Stellar Astrophysics (MESA)
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• Separating gas-giant and ice-giant planets by halting pebble accretion
• Ring shaped dust accumulation in transition disks
• Dust filtration at gap edges: Implications for the spectral energy distributions of discs with embedded planets
• Hints for a Turnover at the Snow Line in the Giant Planet Occurrence Rate
• Stellar and wind properties of massive stars in the central parsec of the Galaxy
• The Photoevaporation of Discs Around Young Stars in Massive Clusters
• "Propeller" Regime of Disk Accretion to Rapidly Rotating Stars
• Gas density drops inside dust cavities of transitional disks around young stars observed with ALMA
• Highly structured disk around the planet host PDS 70 revealed by high-angular resolution observations with ALMA
• Close encounters in young stellar clusters: implications for planetary systems in the solar neighbourhood
• UV Radiation Fields Produced by Young Embedded Star Clusters
• Detection of Galactic Center source G2 at 3.8 $\mu$m during periapse passage
• The Galactic Center cloud G2 and its gas streamer
• The Fate of Binaries in the Galactic Center: The Mundane and the Exotic
• Deserts and pile-ups in the distribution of exoplanets due to photoevaporative disc clearing
• Secular Evolution Of Binaries Near Massive Black Holes: Formation of compact binaries, merger/collision products and G2-like objects
• The evolution of dust in discs influenced by external photoevaporation
• A population of dust-enshrouded objects orbiting the Galactic black hole
• A new Fokker-Planck approach for relaxation-driven evolution of galactic nuclei
• A Cool Accretion Disk around the Galactic Centre Black Hole
• The first multi-dimensional view of mass loss from externally FUV irradiated protoplanetary discs
• A dust and gas cavity in the disc around CQ Tau revealed by ALMA
• Fingerprints of giant planets in the composition of solar twins
• Monitoring the Dusty S-Cluster Object (DSO/G2) on its Orbit towards the Galactic Center Black Hole
• Stellar dynamical evidence against a cold disc origin for stars in the Galactic Centre
• The evolution of photo-evaporating viscous discs in binaries
• Kinematic Structure of the Galactic Center S-cluster
• Accreting planets as dust dams in `transition' discs
• Stellar Distributions Around a Supermassive Black Hole: Strong Segregation Regime Revisited
• The growth of H II regions around massive stars: the role of metallicity and dust
• Accretion of Gas Giants Constrained by the Tidal Barrier
• The influence of the environment on the spin evolution of low-mass stars. I. External photoevaporation of circumstellar disks
• Monitoring dusty sources in the vicinity of Sgr A*
• Makemake + Sedna: A Continuum Radiation Transport and Photoionization Framework for Astrophysical Newtonian Fluid Dynamics
• Gravitational Instabilities induced by Cluster Environment? - The encounter-induced angular momentum transfer in discs
• A Stellar Wind Origin for the G2 Cloud: Three-Dimensional Numerical Simulations
• Testing viscous disc theory using the balance between stellar accretion and external photoevaporation of protoplanetary discs
• The influence of the secular perturbation of an intermediate-mass companion: I. Eccentricity excitation of disk stars at the Galactic center
• Binary companions triggering fragmentation in self-gravitating discs
• Blackhole Mergers Through Evection Resonances
• The apparent tail of the Galactic center object G2/DSO
• An APEX search for carbon emission from NGC 1977 proplyds
• A slim disc approach to external photoevaporation of discs
• The external photoevaporation of planet-forming discs

Cited by in corpus (5)

• The external photoevaporation of structured protoplanetary disks
• X3: a high-mass Young Stellar Object close to the supermassive black hole Sgr~A*
• Candidate Young Stellar Objects in the S-cluster: The Kinematic Analysis of a Sub-population of the Low-mass G-objects close to Sgr A*
• M31 nucleus: molecular and ionised gas content upper limits
• Black Hole Survival Guide: Searching for Stars in the Galactic Center That Endure Partial Tidal Disruption