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 high abundance of disc galaxies without a large central bulge challengespredictions of current hydrodynamic simulations of galaxy formation. We aim toshed light on the formation of these objects by studying the redshift and massdependence of their intrinsic 3D shape distributions in the COSMOS galaxysurvey below redshift $z=1.0$. This distribution is inferred from the observeddistribution of 2D shapes, using a reconstruction method which we test usinghydrodynamic simulations. Our tests reveal a moderate bias for the inferredaverage disc circularity and relative thickness, but a large bias on thedispersion of these quantities. Applying the reconstruction method on COSMOSdata, we find variations of the average disc circularity and relative thicknesswith redshift of around $\sim1\%$ and $\sim10\%$ respectively, which iscomparable to the error estimates on these quantities. The average relativedisc thickness shows a significant mass dependence which can be accounted forby the scaling of disc radius with galaxy mass. We conclude that our dataprovides no evidence for a strong dependence of the average circularity andabsolute thickness of disc-dominated galaxies on redshift and mass that issignificant with respect to the statistical uncertainties in our analysis.These findings are expected in the absence of disruptive merging or feedbackevents that would affect galaxy shapes. They hence support a scenario wherepresent-day discs form early ($z>1.0$) and subsequently undergo a tranquilevolution in isolation. However, more data and a better understanding ofsystematics are needed to reaffirm our results.

Redshift and stellar mass dependence of intrinsic shapes of disc-dominated galaxies from COSMOS observations below $z = 1.0$