Are galactic star formation and quenching governed by local, global, or environmental phenomena?

Quenching of Star Formation

In the last decade we have seen an enormous increase in the size and quality of spectroscopic galaxy surveys, both at low and high redshift. New statistical techniques to analyse large portions of galaxy spectra are now finding favour over traditional index based methods. Here we will review a new robust and iterative Principal Component Analysis (PCA) algorithm, which solves several common iss...

Star Formation and Galactic Evolution

Star Formation Quenching in Quasar Host Galaxies

Galaxy evolution is likely to be shaped by negative feedback from active galactic nuclei (AGN). In the whole range of redshifts and luminosities studied so far, galaxies hosting an AGN frequently show fast and extended outflows consisting in both ionized and molecular gas. Such outflows could potentially quench the start formation within the host galaxy, but a clear evidence of negative feedbac...

Galactic star - formation rates gauged by stellar end - products

Young galactic X-ray point sources (XPs) closely trace the ongoing star formation in galaxies. From measured XP number counts we extract the collective 2-10 keV luminosity of young XPs, L x , which we use to gauge the current star-formation rate (SFR) in galaxies. We find that, for a sample of local star-forming galaxies (i.e., normal spirals and mild starbursts), L x correlates linearly with t...

Global Star Formation Revisited

A general treatment of disk star formation is developed from a dissipative multi-phase model, with the dominant dissipation due to cloud collisions. The Schmidt-Kennicutt law emerges naturally for star-forming disks and starbursts. We predict that there should be an inverse correlation between Tully-Fisher law and Schmidt-Kennicutt law residuals. The model is extended to include a multi-phase t...