Bibcode
Armitage, Thomas J.; Kay, Scott T.; Barnes, David J.; Bahé, Yannick M.; Dalla Vecchia, C.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 482, Issue 3, p.3308-3325
Fecha de publicación:
1
2019
Número de citas
15
Número de citas referidas
15
Descripción
Forthcoming large-scale spectroscopic surveys will soon provide data on
thousands of galaxy clusters. It is important that the systematics of
the various mass estimation techniques is well understood and
calibrated. We compare three different dynamical mass estimators using
the C-EAGLE galaxy clusters, a set of high-resolution simulations with
resolved galaxies a median total mass, M_{200c} = 10^{14.7} M_\odot. We
quantify the bias and scatter of the Jeans, virial, and caustic mass
estimators using all galaxies with a stellar mass M_*\gt 10^9 M_\odot,
both in the ideal 3D case and in the more realistic projected case. On
average we find our mass estimates are unbiased, though relative to the
true mass within r200c the scatter is large with a range of
0.09-0.15 dex. We see a slight increase in the scatter when projecting
the clusters. Selecting galaxies using the same criteria, we find no
significant difference in the mass bias or scatter when comparing
results from hydrodynamical and dark matter only simulations. However,
selecting galaxies by stellar mass reduces the bias compared to
selecting by total mass. Comparing X-ray derived hydrostatic and
dynamical masses, the former are ˜30 per cent lower. We find a
slight dependence between substructure, measured using two different
metrics, and mass bias. In conclusion, we find that dynamical mass
estimators, when averaged together, are unbiased with a scatter of 0.11
± 0.02 dex when including interloper galaxies and with no prior
knowledge of r200c.
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Astrofísica Numérica: Formación y Evolución de Galaxias
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
Claudio
Dalla Vecchia