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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We investigate star formation along the Hubble sequence using the ISO Atlasof Spiral Galaxies. Using mid-infrared and far-infrared flux densitiesnormalized by K-band flux densities as indicators of recent star formation, wefind several trends. First, star formation activity is stronger in late-type(Sc - Scd) spirals than in early-type (Sa - Sab) spirals. This trend is seenboth in nuclear and disk activity. These results confirm several previousoptical studies of star formation along the Hubble sequence but conflict withthe conclusions of most of the previous studies using IRAS data, and we discusswhy this might be so. Second, star formation is significantly more extended inlater-type spirals than in early-type spirals. We suggest that these trends instar formation are a result of differences in the gas content and itsdistribution along the Hubble sequence, and it is these differences thatpromote star formation in late-type spiral galaxies. We also search for trendsin nuclear star formation related to the presence of a bar or nuclear activity.The nuclear star formation activity is not significantly different betweenbarred and unbarred galaxies. We do find that star formation activity appearsto be inhibited in LINERs and transition objects compared to HII galaxies. Themean star formation rate in the sample is 1.4 Msun/yr based on globalfar-infrared fluxes. Combining these data with CO data gives a mean gasconsumption time of 6.4 x 10^8 yr, which is ~5 times lower than the valuesfound in other studies. Finally, we find excellent support for the Schmidt Lawin the correlation between molecular gas masses and recent star formation inthis sample of spiral galaxies.Comment: Accepted by The Astronomical Journal, 20 pages, 14 figure

Star Formation in the [ITAL]Infrared Space Observatory[/ITAL] Atlas of Bright Spiral Galaxies