Buchumschlag

Morphology and Mach number dependence of subsonic Bondi-Hoyle accretion

We carry out three-dimensional computations of the accretion rate onto an object (of size R sink and mass m) as it moves through a uniform medium at a subsonic speed v ∞. The object is treated as a fully absorbing boundary (e.g., a black hole). In contrast to early conjectures, we show that for an a...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Prust, Logan J. (VerfasserIn) , Glanz, Hila (VerfasserIn) , Bildsten, Lars (VerfasserIn) , Perets, Hagai B. (VerfasserIn) , Röpke, Friedrich (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: 2024, May 1
In: The astrophysical journal
Year: 2024, Jahrgang: 966, Heft: 1, Pages: 1-11
ISSN:1538-4357
DOI:10.3847/1538-4357/ad3732
Online-Zugang:Verlag, kostenfrei, Volltext: https://doi.org/10.3847/1538-4357/ad3732
Verlag, kostenfrei, Volltext: https://dx.doi.org/10.3847/1538-4357/ad3732
Volltext
Verfasserangaben:Logan J. Prust, Hila Glanz, Lars Bildsten, Hagai B. Perets and Friedrich K. Röpke
Beschreibung
Zusammenfassung:We carry out three-dimensional computations of the accretion rate onto an object (of size R sink and mass m) as it moves through a uniform medium at a subsonic speed v ∞. The object is treated as a fully absorbing boundary (e.g., a black hole). In contrast to early conjectures, we show that for an accretor with in a gaseous medium with adiabatic index γ = 5/3, the accretion rate is independent of Mach number and is determined only by m and the gas entropy. Our numerical simulations are conducted using two different numerical schemes via the Athena++ and Arepo hydrodynamics solvers, which reach nearly identical steady-state solutions. We find that pressure gradients generated by the isentropic compression of the flow near the accretor are sufficient to suspend much of the surrounding gas in a near-hydrostatic equilibrium, just as predicted from the spherical Bondi-Hoyle calculation. Indeed, the accretion rates for steady flow match the Bondi-Hoyle rate, and are indicative of isentropic flow for subsonic motion where no shocks occur. We also find that the accretion drag may be predicted using the Safronov number, Θ = R A /R sink, and is much less than the dynamical friction for sufficiently small accretors (R sink ≪ R A ).
Beschreibung:Gesehen am 22.10.2024
Beschreibung:Online Resource
ISSN:1538-4357
DOI:10.3847/1538-4357/ad3732

Ähnliche Einträge