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Another Flattened Dark Halo: Plar Ring Galaxy A0136-0801

Astrophysics 2009-10-22 v1

Abstract

Knowledge of the shape of dark matter halos is critical to our understanding of galaxy formation, dynamics, and of the nature of dark matter itself. Polar ring galaxies (PRGs) --- early-type galaxies defined by their outer rings of gas, dust and stars on orbits nearly perpendicular to those of the central host --- provide a rare probe of the vertical-to-radial axis ratio (qρ=c/a) (q_{\rho} = c/a) of dark halos. We present a Fabry-Perot velocity field for the Hα\alpha gas in the kinematically-confirmed PRG \gal. By comparing ring orbits evolved in a generalized mass model to the observed ring velocity field and morphology of \gal, we conclude that qρ0.5q_\rho \sim 0.5 and rule out a spherical geometry.

Keywords

Cite

@article{arxiv.astro-ph/9412011,
  title  = {Another Flattened Dark Halo: Plar Ring Galaxy A0136-0801},
  author = {Penny D. Sackett and Richard W. Pogge},
  journal= {arXiv preprint arXiv:astro-ph/9412011},
  year   = {2009}
}

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uuencoded gz-compressed file with figures included