[phys4phys] Naučno-stručni skup AOB - sreda 14.5.2025. u 13h

[Natasa Bon]

Poštovane kolege,

Pozivam vas na Naučno-stručni skup koji će se održati u biblioteci AOB u 
sredu 14.5.2025. u 13h.

Predavač je Michal Bilek.

U nastavku je apstrakt predavanja.

Title: Formation of Fornax dwarf spheroidal and the survival of its 
globular clusters in MOND

Abstract:
The presence of globular clusters (GCs) in the Fornax dwarf spheroidal 
is an important test of the theories aiming to address the missing mass 
problem. The problem is that in most of them, the GCs are expected to 
sink in the center of Fornax due to dynamical friction much faster than 
the observed stellar ages of the GCs. I will present our assessment of 
the problem in the framework of MOND modified gravity using N-body 
simulations. Following older MOND studies of the Local Group, we assumed 
that Fornax is a tidal dwarf galaxy formed in a Milky Way - Andromeda 
flyby 7 Gyr ago. We newly propose that the GCs of Fornax started their 
lives as massive star clusters in the young Milky Way. Our results are 
the following:
1) The scenario can explain why the Milky Way has a disk of satellites, 
whose member Fornax is.
2) The simulations show that the probability that Fornax has five unsunk 
GCs as observed is 20%, which is not low enough to exclude MOND.
3) The simulations also explain why the GCs have the observed 
distribution of distances from Fornax.
4) For the latest proper motion, MOND gravity implies an orbit of Fornax 
whose perigalacticons perfectly agree with the observed peaks of star 
formation in Fornax.
5) Without any tuning, the simulations reproduce the observed "stellar 
halo" of Fornax.
6) A stellar stream is predicted to extend from Fornax which could be 
currently detectable.
7) By an additional simulation, we show that if Fornax stared its life 
as a rotating disky tidal dwarf galaxy, the varying tidal forces from 
the Milky Way were able to transform it into a non-rotating spheroidal.

Predavanje možete pratiti i online putem ZOOM-a:

  https://zoom.us/j/97531689754?pwd=9MOlzuLwJgEd46kjlkOCAu9gjZwK4H.1

  Meeting ID:975 3168 9754


Srdačan pozdrav,

Nataša




dr Natasa Gavrilovic Bon
Associate Research Professor
web site: http://nbon.aob.rs/
Astronomical Observatory Belgrade
Volgina 7
11160 Belgrade, Serbia
Tel:+381 11 3089 068
Fax:2419 553