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

The cluster environment can affect galaxy evolution in different ways: viaram pressure stripping or by gravitational perturbations caused by galacticencounters. New IRAM 30m HERA CO(2-1) data of NGC 4501 and NGC 4567/68 arepresented. We find an increase in the molecular fraction where the ISM iscompressed. The gas is close to self-gravitation in compressed regions. Thisleads to an increase in gas pressure and a decrease in the ratio between themolecular fraction and total ISM pressure. The overall Kennicutt Schmidtrelation based on a pixel-by-pixel analysis at ~1.5 kpc resolution is notsignificantly modified by compression. However, we detected continuous regionsof low molecular star formation efficiencies in the compressed parts of thegalactic gas disks. The data suggest that a relation between the molecular starformation efficiency SFE_H2 and gas self-gravitation exists. Both systems showspatial variations in the star formation efficiency with respect to themolecular gas that can be related to environmental compression of the ISM. Ananalytical model was used to investigate the dependence of SFE_H2 onself-gravitation. The model correctly reproduces the correlations betweenR_mol/P_tot, SFE_H2, and Toomre Q if different global turbulent velocitydispersions are assumed for the three galaxies. We found that variations in theN_H_2/I_CO conversion factor can mask most of the correlation between SFE_H2and the Q parameter. Dynamical simulations were used to compare the effects ofram pressure and tidal ISM compression. We conclude that a gravitationallyinduced ISM compression has the same consequences as ram pressure compression:(i) an increasing gas surface density, (ii) an increasing molecular fraction,and (iii) a decreasing R_mol/P_tot in the compressed region due to the presenceof nearly self-gravitating gas. The response of SFE_H2 to compression is morecomplex.

Effects of environmental gas compression on the multiphase ISM and star formation