HI synthesis observations of the blue compact dwarf NGC 1705

TL;DR

This study uses HI-line observations from the Australia Telescope Compact Array to analyze the dwarf galaxy NGC 1705, revealing a dense, compact dark matter halo dominating its gravitational potential.

Contribution

First detailed HI observations of NGC 1705's gravitational potential and mass modeling showing a denser, more compact dark matter halo than previously estimated.

Findings

Dark matter dominates the galaxy's gravitational potential.

NFW and pseudo-isothermal sphere models fit the data well.

The dark matter halo is denser and more compact than earlier thought.

Abstract

Australia Telescope Compact Array HI-line observations of the nearby dwarf galaxy NGC 1705 are presented. The data are used to trace the gravitational potential of the galaxy out to several stellar disc scale lengths. A rotation curve is derived for the system and used to generate mass models. Dark matter dominates the gravitational potential at nearly all galactocentric radii. NFW and pseudo-isothermal sphere halo parameterisations allowing for good reproductions of the observations. The models suggest NGC 1705 to have a dark matter halo that it much denser and more compact than previously thought.