Galaxies with monstrous black holes in galaxy cluster environments

van Son, Lieke A. C.; Barber, Christopher; Bahé, Y. M.; Schaye, Joop; Barnes, David J.; Crain, Robert A.; Kay, Scott T.; Theuns, Tom; Dalla Vecchia, C.
Referencia bibliográfica

Monthly Notices of the Royal Astronomical Society, Volume 485, Issue 1, p.396-407

Fecha de publicación:
5
2019
Número de autores
9
Número de autores del IAC
1
Número de citas
15
Número de citas referidas
15
Descripción
Massive early-type galaxies follow a tight relation between the mass of their central supermassive black hole (MBH) and their stellar mass (M⋆). The origin of observed positive outliers from this relation with extremely high MBH (> 109 M_{⊙ }) remains unclear. We present a study of such outliers in the Hydrangea/C-EAGLE cosmological hydrodynamical simulations, designed to enable the study of high-mass galaxy formation and evolution in cluster environments. We find 69 MBH(M⋆) outliers at z = 0, defined as those with M_BH> 107 M_{⊙ } and MBH/M⋆ > 0.01. This paper focuses on a sample of five extreme outliers, that have been selected based on their MBH and M⋆ values, which are comparable to the most recent estimates of observed positive outliers. This sample of five outliers, classified as `black hole monster galaxies' (BMGs), was traced back in time to study their origin and evolution. In agreement with the results of previous simulations for lower mass MBH(M⋆) outliers, we find that these galaxies became outliers due to a combination of their early formation times and tidal stripping. For BMGs with M_BH> 10^9 M_{⊙ }, major mergers (with a stellar mass ratio of μ > 0.25) at early times (z > 2) precede the rapid growth of their supermassive BHs. Furthermore, the scatter in the relation between MBH and stellar velocity dispersion, σ, correlates positively with the scatter in [Mg/Fe](σ). This indicates that the alpha enhancement of these galaxies, which is closely related to their star formation history, is related to the growth of their central BHs.
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Entre las cuestiones fundamentales en Astronomía y Astrofísica están la formación y evolución de galaxias. Las escalas de tiempo y tamaño son tan astronómicas que su observación en galaxias individuales es imposible. Solo con el uso de simulaciones numéricas es posible entender la formación de estructuras cósmicas dentro del actual marco
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