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

The gas-stars instability criterion for infinitesimally thin disc was appliedto the galaxy NGC 628. Instead of using the azimuthally averaged profiles ofdata the maps of the gas surface densities (THINGS, HERACLES), of the velocitydispersions of stars (VENGA) and gas (THINGS) and of the surface brightness ofthe galaxy (S$^4$G) were analyzed. All these maps were collected for the sameregion with a noticeable star formation rate and were superimposed on eachother. Using the data on the rotation curve values of $Q_\mathrm{eff}$ werecalculated for each pixel in the image. The areas within the contours$Q_\mathrm{eff}<3$ were compared with the ongoing star formation regions($\Sigma_\mathrm{SFR}> 0.007 \, M_{\odot}$yr$^{-1}$kpc$^{-2}$) and showed agood coincidence between them. The Romeo-Falstad disc instability diagnosticstaking into account the thickness of the stellar and gas layers does not changethe result. If the one-fluid instability criterion is used, the coincidence isworse. The analysis was carried out for the area $r < $ 0.5$r_{25} $. Leroy etal. (2008) using azimuthally averaged data obtained $Q_\mathrm{eff} \approx3-4$ for this area of the disc, which makes it stable against non-axisymmetricperturbations and gas dissipation, and does not predict the location of starforming regions. Since in the galaxies the distribution of hydrogen and theregions of star formation is often patchy, the relationship betweengravitational instability and star formation should be sought using data mapsrather than azimuthally averaged data.

Gravitational instability and star formation in NGC 628