TY - JOUR

T1 - Analytical and Numerical Studies of Central Galactic Outflows Powered by Tidal Disruption Events

T2 - A Model for the Fermi Bubbles?

AU - Ko, C. M.

AU - Breitschwerdt, D.

AU - Chernyshov, D. O.

AU - Cheng, H.

AU - Dai, L.

AU - Dogiel, V. A.

PY - 2020/11/20

Y1 - 2020/11/20

N2 - Capture and tidal disruption of stars by the supermassive black hole in the Galactic center (GC) should occur regularly. The energy released and dissipated by these processes will affect both the ambient environment of the GC and the Galactic halo. The single star of a super-Eddington eruption generates a subsonic outflow with an energy release of more than 10(52) erg, which still is not high enough to push shock heated gas into the halo. Only routine tidal disruption of stars near the GC can provide enough cumulative energy to form and maintain largescale structures like the Fermi Bubbles. The average rate of disruption events is expected to be 10(-4) similar to 10(-5) yr(-1), providing the average power of energy release from the GC into the halo of (W)over dot similar to 3 x 10(41) erg s(-1), which is needed to support the Fermi Bubbles. The GC black hole is surrounded by molecular clouds in the disk, but their overall mass and filling factor are too low to significantly stall the shocks from tidal disruption events. The de facto continuous energy injection on timescales of megayears will lead to the propagation of strong shocks in a density stratified Galactic halo and thus create elongated bubble-like features that are symmetric to the Galactic midplane.

AB - Capture and tidal disruption of stars by the supermassive black hole in the Galactic center (GC) should occur regularly. The energy released and dissipated by these processes will affect both the ambient environment of the GC and the Galactic halo. The single star of a super-Eddington eruption generates a subsonic outflow with an energy release of more than 10(52) erg, which still is not high enough to push shock heated gas into the halo. Only routine tidal disruption of stars near the GC can provide enough cumulative energy to form and maintain largescale structures like the Fermi Bubbles. The average rate of disruption events is expected to be 10(-4) similar to 10(-5) yr(-1), providing the average power of energy release from the GC into the halo of (W)over dot similar to 3 x 10(41) erg s(-1), which is needed to support the Fermi Bubbles. The GC black hole is surrounded by molecular clouds in the disk, but their overall mass and filling factor are too low to significantly stall the shocks from tidal disruption events. The de facto continuous energy injection on timescales of megayears will lead to the propagation of strong shocks in a density stratified Galactic halo and thus create elongated bubble-like features that are symmetric to the Galactic midplane.

KW - Galactic center

KW - Interstellar clouds

KW - Galactic winds

KW - Tidal disruption

KW - Superbubbles

KW - Gamma-rays

KW - Cosmic rays

KW - MASSIVE BLACK-HOLE

KW - SGR A-ASTERISK

KW - INTERSTELLAR-MEDIUM

KW - RAY

KW - MILKY

KW - STARS

KW - EMISSION

KW - RATES

KW - PARSECS

KW - GAS

U2 - 10.3847/1538-4357/abbda4

DO - 10.3847/1538-4357/abbda4

M3 - Journal article

VL - 904

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 46

ER -