DFUDG

An N-body simulation with semi-analytic dynamical friction, geared towards dynamics of globular-cluster rich ultra-diffuse galaxies.

Sample Results

Here we reproduce some of the main figures from Bar et al. (2022) (see citation below) that demonstrate the data that the code is useful for.

The above is a reproduction of the Hubble Space Telescope data of NGC5846-UDG1 galaxy and a nearby field from Danieli et al. (2022), indicating globular-cluster (GC) candidates. On the right, the data is binned into luminosity bins with circles charcterising the stellar body. We primarily use a subset of the data in the high-luminosity end as it is weakly affected by contamination.

The above on the left is projected-radii of candidate GCs vs. their estimated luminosity (taken from the raw data above), accompanied with luminosity-binned estimates. The figure indicates mass segregation that we may be able to explain from galactic dynamics.

The above on the right is an example of the result of 40 realizations of 33 massive candidate globular clusters (GCs) of NGC5846-UDG1 in a Burkert profile, integrated over 10 Gyr. Initial conditions of GCs are taken to be common across different GC masses. The error-bars of simulations denote 1-σ confidence intervals. Eq. (2) approx. refers to a simple analytic approximation developed in Bar et al. (2022) which reasonably agrees with simulations.

Using the code, we find that galactic dynamics - dynamical friction, mostly - can provide a natural explanation for the mass segregation observed in the data. We hope that the code will be useful for future studies of similar galaxies.

Usage

To generate all simulations, run

MainScript.m

To generate all figures, run

MainScriptPrint.m

To generate a video, run

MainScriptVideo.m

It is recommended to treat the different scripts as notebooks and to run a subset of them.

License

This code is under MIT license.

BibTeX entry

If you use this code or find it in any way useful for your research, please cite Bar, Danieli, and Blum (2022). The BibTeX entry is:

@article{Bar:2022liw,
author = "Bar, Nitsan and Danieli, Shany and Blum, Kfir",
title = "{Dynamical friction in globular cluster-rich ultra-diffuse galaxies: the case of NGC5846-UDG1}",
eprint = "2202.10179",
archivePrefix = "arXiv",
primaryClass = "astro-ph.GA",
year = "2022"
}