The PAndAS View of the Andromeda Satellite System. IV. Global Properties

Doliva-Dolinsky, Amandine; Martin, Nicolas F.; Yuan, Zhen; Savino, Alessandro; Weisz, Daniel R.; Ferguson, Annette M. N.; Ibata, Rodrigo A.; Kim, Stacy Y.; Lewis, Geraint F.; McConnachie, Alan W.; Thomas, Guillaume F.
Referencia bibliográfica

The Astrophysical Journal

Fecha de publicación:
Número de autores
Número de autores del IAC
Número de citas
Número de citas referidas
We build a statistical framework to infer the global properties of the satellite system of the Andromeda galaxy (M31) from the properties of individual dwarf galaxies located in the Pan-Andromeda Archaelogical Survey (PAndAS) and the previously determined completeness of the survey. Using forward modeling, we infer the slope of the luminosity function of the satellite system, the slope of its spatial density distribution, and the size-luminosity relation followed by the dwarf galaxies. We find that the slope of the luminosity function is β = -1.5 ± 0.1. Combined with the spatial density profile, it implies that, when accounting for survey incompleteness, M31 hosts ${92}_{-26}^{+19}$ dwarf galaxies with M V < -5.5 and a sky-projected distance from M31 between 30 and 300 kpc. We conclude that many faint or distant dwarf galaxies remain to be discovered around Andromeda, especially outside the PAndAS footprint. Finally, we use our model to test if the higher number of satellites situated in the hemisphere facing the Milky Way could be explained simply by the detection limits of dwarf galaxy searches. We rule this out at >99.9% confidence and conclude that this anisotropy is an intrinsic feature of the M31 satellite system. The statistical framework we present here is a powerful tool to robustly constrain the properties of a satellite system and compare those across hosts, especially considering the upcoming start of the Euclid or Rubin large photometric surveys that are expected to uncover a large number of dwarf galaxies in the Local Volume.
Proyectos relacionados
Una vista de nuestra galaxia, la Vía Láctea, con sus vecinos cercanos,  las Nubes de Magallanes
Evolución Galáctica en el Grupo Local

La formación y evolución de galaxias es un problema fundamental en Astrofísica. Su estudio requiere “viajar atrás en el tiempo”, para lo cual hay dos enfoques complementarios. El mas extendido consiste en analizar las propiedades de las galaxias a diferentes distancias cosmológicas. Nuestro equipo se concentra en el otro enfoque, denominado