Bibcode
Hayashi, K.; Fabrizio, Michele; Łokas, Ewa L.; Bono, Giuseppe; Monelli, M.; Dall'Ora, Massimo; Stetson, Peter B.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 481, Issue 1, p.250-261
Advertised on:
11
2018
Citations
15
Refereed citations
13
Description
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.
Related projects
Galaxy Evolution in the Local Group
Galaxy formation and evolution is a fundamental Astrophysical problem. Its study requires “travelling back in time”, for which there are two complementary approaches. One is to analyse galaxy properties as a function of red-shift. Our team focuses on the other approach, called “Galactic Archaeology”. It is based on the determination of galaxy
Matteo
Monelli