Bibcode
Hayashi, K.; Fabrizio, Michele; Łokas, Ewa L.; Bono, Giuseppe; Monelli, M.; Dall'Ora, Massimo; Stetson, Peter B.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 481, Issue 1, p.250-261
Fecha de publicación:
11
2018
Número de citas
15
Número de citas referidas
13
Descripción
Photometric and spectroscopic observations of the Carina dSph revealed
that this galaxy contains two dominant stellar populations of different
age and kinematics. The coexistence of multiple populations provides new
constraints on the dark halo structure of the galaxy, because different
populations should be in equilibrium in the same dark matter potential
well. We develop non-spherical dynamical models including such multiple
stellar components and attempt to constrain the properties of the
non-spherical dark halo of Carina. We find that Carina probably has a
larger and denser dark halo than found in previous works and a less
cuspy inner dark matter density profile, even though the uncertainties
of dark halo parameters are still large due to small volume of data
sample. Using our fitting results, we evaluate astrophysical factors for
dark matter annihilation and decay and find that Carina should be one of
the most promising detectable targets among classical dSph galaxies. We
also calculate stellar velocity anisotropy profiles for both stellar
populations and find that they are both radially anisotropic in the
inner regions, while in the outer regions the older population becomes
more tangentially biased than the intermediate ones. This is consistent
with the anisotropy predicted from tidal effects on the dynamical
structure of a satellite galaxy and thereby can be considered as
kinematic evidence for the tidal evolution of Carina.
Proyectos relacionados
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
Matteo
Monelli