English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present 21cm HI line observations of the blue compact dwarf galaxyNGC1705. Previous optical observations show a strong outflow powered by anongoing starburst dominating the HII morphology and kinematics. In contrast,most of the HI lies in a rotating disk. An extraplanar HI spur accounts for ~8% of the total HI mass, and is possibly associated with the HII outflow. Theinferred mass loss rate out of the galaxy's core is significant ~ 0.2 - 2M_sun/yr, but does not dominate the HI dynamics. Mass model fits to therotation curve show that the dark matter (DM) halo is dominant at nearly allradii and has a central density \rho_0 \approx 0.1 M_sun/pc^3: ten times higherthan typically found in dwarf irregular galaxies, but similar to the only othermass-modelled blue compact dwarf, NGC2915. This large difference stronglyindicates that there is little evolution between dwarf irregular and bluecompact dwarf types. Instead, dominant DM halos may regulate the morphology ofdwarf galaxies by setting the critical surface density for disk star formation.Neither our data nor catalogue searches reveal any likely external trigger tothe starburst in NGC1705.Comment: Accepted by MNRAS. 14 pages, 12 figures, uses mn.sty, psfig.st

H i and dark matter in the windy starburst dwarf galaxy NGC 1705