Satellite Galaxy Velocity Dispersions in the SDSS and Modified Gravity Models

Galaxies

John W. Moffat¹ 

[1] Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5, Canada; E-Mail:

关键词: galaxies;    halos;    structure;    gravitation;    surveys;   

DOI  :  10.3390/galaxies2020263

来源: mdpi

【 摘 要 】

The Sloan Digital Sky Survey (SDSS) provides data on several hundred thousand galaxies. The precise location of these galaxies in the sky, along with information about their luminosities and line-of-sight (Doppler) velocities, allows one to construct a three-dimensional map of their location and estimate their line-of-sight velocity dispersion. This information, in principle, allows one to test dynamical gravity models, specifically models of satellite galaxy velocity dispersions near massive hosts. A key difficulty is the separation of true satellites from interlopers. We sidestep this problem by not attempting to derive satellite galaxy velocity dispersions from the data, but instead incorporate an interloper background into the mathematical models and compare the result to the actual data. We find that due to the presence of interlopers, it is not possible to exclude several gravitational theories on the basis of the SDSS data.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.