Three-Dimensional Moving-Mesh Simulations of Galactic Center Cloud G2

Abstract

Using three-dimensional, moving-mesh simulations, we investigate the future evolution of the recently discovered gas cloud G2 traveling through the galactic center. We consider the case of a spherical cloud initially in pressure equilibrium with the background. Our suite of simulations explores the following parameters: the equation of state, radial profiles of the background gas, and start times for the evolution. Our primary focus is on how the fate of this cloud will affect the future activity of Sgr A*. From our simulations we expect an average feeding rate in the range of $5-19\times 10^{-8}$ solar masses per year beginning in 2013 and lasting for at least 7 years (our simulations stop in year 2020). The accretion varies by less than a factor of three on timescales <1 month, and shows no more than a factor of 10 difference between the maximum and minimum. These rates are comparable to the current estimated accretion rate in the immediate vicinity of Sgr A*, although they represent only a small (<5%) increase over the current expected feeding rate at the effective inner boundary of our simulations. Therefore, the break up of cloud G2 may have only a minimal effect on the brightness and variability of Sgr A* over the next decade. This is because current models of the galactic center predict that most of the gas will be caught up in outflows. However, if the accreted G2 material can remain cold, it may not mix well with the hot, diffuse background gas, and instead accrete efficiently onto Sgr A*. Further observations of G2 will give us an unprecedented opportunity to test this idea. The break up of the cloud itself may also be observable. By tracking the amount of cloud energy that is dissipated during our simulations, we are able to get a rough estimate of the luminosity associated with its tidal disruption; we find values of a few $10^{36}$ erg/s.

14 pages, 8 figures, final accepted version

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Cited by in corpus (44)

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• Hydrodynamical simulations of a compact source scenario for the Galactic Center cloud G2
• Possible Origin of the G2 Cloud from the Tidal Disruption of a Known Giant Star by Sgr A*
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• Flaring up of the Compact Cloud G2 during the Close Encounter with Sgr A*
• Spitzer/IRAC Observations of the Variability of Sgr A* and the Object G2 at 4.5 microns
• Relativistic Tidal Disruption and Nuclear Ignition of White Dwarf Stars by Intermediate Mass Black Holes
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• A Stellar Wind Origin for the G2 Cloud: Three-Dimensional Numerical Simulations
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• Hydrodynamic Shielding and the Survival of Cold Streams
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• Simulating the effect of the Sgr A* accretion flow on the appearance of G2 after pericenter
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• Nuclear Ignition of White Dwarf Stars by Relativistic Encounters with Rotating Intermediate Mass Black Holes
• A Possible Time-Delayed Brightening of the Sgr A* Accretion Flow after the Pericenter Passage of G2 Cloud
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• 3D AMR hydrosimulations of a compact source scenario for the Galactic Centre cloud G2
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• Colliding with G2 near the Galactic Centre: a geometrical approach
• Hydrodynamical simulations of a compact source scenario for G2
• G2 and Sgr A*: A Cosmic Fizzle At The Galactic Center
• Theory of G2 Cloud Multi-Wavelength Emission
• Update on 3D Moving Mesh Simulations of Galactic Center Cloud G2
• Resolution Study of Thermonuclear Initiation in White Dwarf Tidal Disruption Events