English

The connection between the cusp-to-core transformation and observational universalities of DM halos

Cosmology and Nongalactic Astrophysics 2014-03-05 v2

Abstract

Observations have revealed interesting universal properties of dark matter (DM) halos especially around low-mass galaxies. Strigari et al. (2008) showed that DM halos have common enclosed masses within 300pc (Strigari relation). Kormendy & Freeman (2004) reported DM halos having almost identical central surface densities (the μ0D\mu_{\rm 0D} relation). In addition, there exists a core-cusp problem, a discrepancy of the central density distribution between simulated halos and observations. We investigate whether a scenario where cuspy halos transform into cores by some dynamical processes can also explain their universal structural properties. It is shown that a cusp-to-core transformation model naturally reproduces the μ0D\mu_{\rm 0D} relation and that Strigari relation follows from the μ0D\mu_{\rm 0D} relation for dwarf galaxies. We also show that the central densities of cored dark halos provide valuable information about their formation redshifts.

Keywords

Cite

@article{arxiv.1309.1646,
  title  = {The connection between the cusp-to-core transformation and observational universalities of DM halos},
  author = {Go Ogiya and Masao Mori and Tomoaki Ishiyama and Andreas Burkert},
  journal= {arXiv preprint arXiv:1309.1646},
  year   = {2014}
}

Comments

5 pages, 3 figures, accepted for publication in MNRAS Letters