[AAA] SEMINARIO VIRTUAL IATE (10/06 -14:00 hs)

[Seminarios IATE - Conicet]

*Título: *Modelling the formation of the GD-1 stellar stream inside a host
with a fermionic dark matter core-halo distribution

*Expositor:* Dr. Martín Mestre (Instituto de Astrofísica de La Plata -
Facultad de Ciencias Astronómicas y Geofísicas de La Plata)

*Fecha:* viernes 10 de junio, 14 hs

*Resumen:  *Stellar streams are a consequence of the tidal forces produced
by a host galaxy on its satellites (i.e. globular clusters and dwarf
spheroidals).
As the self-gravity of stellar streams is almost negligible, they
constitute excellent probes of the gravitational potential of the host
galaxy.
For this reason, some Milky Way stellar streams have been used to put
constraints on the dark matter (DM) total mass and shape, under
empirical DM distributions (i.e. NFW, logarithmic, etc). In particular,
Malhan et Ibata (2019) have fitted the GD-1 orbit embedded in an
axisymmetric NFW potential plus baryons, obtaining that the density
flattening of the dark halo is slightly oblate.

In this work we show that it is possible to model the GD-1 stellar stream
using a spherical dark matter distribution previously deduced from
first principles by means of the maximization of the coarse-grained entropy
for self-gravitating fermions. For that purpose we used a genetic
algorithm in order to fit both the stream orbit's initial conditions and
the fermionic halo. We modelled the baryonic potential with a bulge and
two disks (thin and thick) with fixed parameters according to the recent
literature. The stream observable is 6D phase-space data from Ibata
et al. (2020), including the Gaia DR2 survey.  Besides, our fitted halo
model is, by construction, in agreement with the orbits of the S-stars at
Sagittarius A*, thus mimicking the paradigmatic supermassive black hole
gravitational effect.

Esperamos vuestra participación este viernes mediante el enlace:
https://meet.google.com/dww-axto-tdf
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