Habitable Zones & Global Climate

The Impact of Tidal Disruption Events on Galactic Habitability

By Keith Cowing
Press Release
August 25, 2020
Filed under
The Impact of Tidal Disruption Events on Galactic Habitability
Total mass (in units of the Earth’ĂŹs present-day atmospheric mass) lost by a terrestrial planet at distance D. The left panel depicts the contribution from the AGN phase (Balbi & Tombesi 2017). The right panel illustrates the total radiative feedback from Sgr A*, i.e., considering the AGN phase and TDEs over a span of 5 Gyr. We show the results for two values of the efficiency of hydrodynamic escape (ε) and the optical depth (τ), which parametrizes the presence (τ = 1) or absence (τ = 0) of the obscuring torus during the AGN phase.

Tidal Disruption Events (TDEs) are characterized by the emission of a short burst of high-energy radiation. We analyze the cumulative impact of TDEs on galactic habitability using the Milky Way as a proxy.

We show that X-rays and extreme ultraviolet (XUV) radiation emitted during TDEs can cause hydrodynamic escape and instigate biological damage. By taking the appropriate variables into consideration, such as the efficiency of atmospheric escape and distance from the Galactic center, we demonstrate that the impact of TDEs on galactic habitability is comparable to that of Active Galactic Nuclei. In particular, we show that planets within distances of ∼0.1-1 kpc could lose Earth-like atmospheres over the age of the Earth, and that some of them might be subject to biological damage once every ≳104 yrs. We conclude by highlighting potential ramifications of TDEs and argue that they should be factored into future analyses of inner galactic habitability.

E. Pacetti, A. Balbi, M. Lingam, F. Tombesi, E. Perlman

Comments: MNRAS, in press
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)
DOI: 10.1093/mnras/staa2535
Cite as: arXiv:2008.09988 [astro-ph.EP] (or arXiv:2008.09988v1 [astro-ph.EP] for this version)
Submission history
From: Amedeo Balbi
[v1] Sun, 23 Aug 2020 08:04:07 UTC (43 KB)

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