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

It has recently been shown that galaxy formation models within the Λ cold dark matter cosmology predict that, compared to the observed population, small galaxies (with stellar masses  &lt;10 11  M ⊙  ) form too early, are too passive since   z ∼ 3  and host too old stellar populations at   z = 0 . We then expect an overproduction of small galaxies at   z ≳ 4  that should be visible as an excess of faint Lyman‐break galaxies. To check whether this excess is present, we use the  morgana  galaxy formation model and  grasil  spectrophotometric  +  radiative transfer code to generate mock catalogues of deep fields observed with  Hubble Space Telescope  Advanced Camera for Surveys. We add observational noise and the effect of Lyman α emission, and perform colour–colour selections to identify Lyman‐break galaxies. The resulting mock candidates have plausible properties that closely resemble those of observed galaxies. We are able to reproduce the evolution of the bright tail of the luminosity function of Lyman‐break galaxies (with a possible underestimate of the number of the brightest  i ‐dropouts), but uncertainties and degeneracies in dust absorption parameters do not allow to give strong constraints to the model. Besides, our model shows a clear excess with respect to observations of faint Lyman‐break galaxies, especially of   z  850 ∼ 27 V  ‐dropouts at   z ∼ 5 . We quantify the properties of these ‘excess’ galaxies and discuss the implications: these galaxies are hosted in dark matter haloes with circular velocities in excess of 100 km s −1 , and their suppression may require a deep rethinking of stellar feedback processes taking place in galaxy formation.

Faint Lyman‐break galaxies as a crucial test for galaxy formation models