Impact of Dynamical Friction on the Tidal Formation of NGC 1052-DF2

Author:

Ryosuke Katayama, Kentaro Nagamine

Keyword:

Astrophysics, Astrophysics of Galaxies, Astrophysics of Galaxies (astro-ph.GA), Cosmology and Nongalactic Astrophysics (astro-ph.CO)

journal:

date:

2023-06-12 16:00:00

Abstract

If a normal dwarf satellite galaxy repeatedly suffers from strong tidal forces while orbiting a massive halo, it can turn into a dark matter-deficient galaxy (DMDG). It has been shown that NGC 1052-DF2 can form due to this tidal scenario by N-body simulation; however, the dynamical friction has been ignored in the literature. We perform a self-consistent full N-body simulation to investigate the effect of dynamical friction on the formation scenario and compare it with the one without dynamical friction. We find that dynamical friction causes a dramatic decay of the satellite's orbit. This makes the orbital period shorter, and the mass of the satellite decreases more rapidly. As a result, the satellite galaxy suffering from dynamical friction becomes a DMDG in $\approx 7-8$ Gyr, which is $\approx 2-3$ Gyr earlier than that in the simulation without dynamical friction. Although the distribution of the globular clusters (GCs) in our simulation does not fully agree with that of DF2, the current observations still have large uncertainties. Our result implies that DF2 can be formed by a more circular orbit within a Hubble time, and that DMDGs can be formed by this tidal scenario more often than previously thought.

PDF: Impact of Dynamical Friction on the Tidal Formation of NGC 1052-DF2.pdf