Is Dark Matter in Spiral Galaxies Cold Gas? I. Observational Constraints and Dynamical Clues About Galaxy Evolution

TL;DR

This paper suggests that dark matter in spiral galaxies may be composed of cold, molecular gas that is rotationally supported, based on dynamical constraints and observational data about galaxy evolution.

Contribution

It introduces the novel hypothesis that dark matter around spiral galaxies is primarily cold molecular gas, supported by observational and dynamical evidence.

Findings

Dark matter may be in the form of cold molecular gas

Supports the idea of rotational support for dark matter

Provides observational constraints on galaxy evolution

Abstract

Based on dynamical constraints about the Hubble sequence evolution, observational data and a number of "conspiracies", we propose that the dark matter around spiral galaxies is in the form of cold gas, essentially in molecular form and rotationally supported. (full A&A paper (in press) available by anonymous ftp at obssd8.unige.ch in /pub/fractal as postscript file: dm_paper_I.ps (170k), or papers I & II + figures as a compressed tar file dm_papers.Z.tar (2.1 Mb)).