4.7 Article

The thickness of HI in galactic discs under MOdified Newtonian Dynamics:: theory and application to the Galaxy

期刊

出版社

OXFORD UNIV PRESS
DOI: 10.1111/j.1365-2966.2008.12941.x

关键词

gravitation; Galaxy : disc; galaxies : haloes; galaxies : kinematics and dynamics; galaxies : structure

向作者/读者索取更多资源

The outskirts of galaxies are a very good laboratory for testing the nature of the gravitational field at low accelerations. By assuming that the neutral hydrogen gas is in hydrostatic equilibrium in the gravitational potential of the host galaxy, the observed flaring of the gas layer can be used to test modified gravities. For the first time, we construct a simple framework to derive the scaleheight of the neutral hydrogen gas disc in the MOdified Newtonian Dynamics (MOND) scenario and apply this to the Milky Way. It is shown that using a constant gas velocity dispersion of similar to 9 km s(-1), MOND is able to give a very good fit to the observed H I flaring beyond a galactocentric distance of 17 kpc up to the last measured point (similar to 40 kpc). Between 10 and 16 kpc, however, the observed scaleheight is about 40 per cent more than what MOND predicts for the standard interpolating function and 70 per cent for the form suggested by Famaey & Binney. Given the uncertainties in the non-thermal pressure support by cosmic rays and magnetic fields, MOND seems to be a plausible alternative to dark matter in explaining the Milky Way flaring. Studying the flaring of extended H I discs in external edge-on galaxies may be a promising approach to assess the viability of MOND.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据