Investigating the link between inner gravitational potential and star-formation quenching in CALIFA galaxies

It has been suggested that the gravitational potential can have a significant role in suppressing the star formation in the nearby galaxies. To establish observational constrains on this scenario, we investigate the connection between the dynamics, through the circular velocity curves (CVCs) as a proxy of the inner gravitational potential, and star formation quenching in 215 non-active galaxies across Hubble sequence from the Calar Alto Legacy Integral Field Area (CALIFA) survey. Our results show that galaxies with similar CVCs tend to have a certain star-formation quenching pattern. To explore these findings in more details, we construct kpc-resolved relations of the equivalent width of the H$α$ ($W_{{\rm H}α}$) versus the amplitude ($V_c$) and shape ($β= d\ln V_c/ d\ln R$) of the circular velocity at given radius. We find that the $W_{{\rm H}α}-V_c$ is a declining relationship, where the retired regions of the galaxies (the ones with $W_{{\rm H}α}$ values below 3 Å) tend to have higher $V_c$. Differently, $W_{{\rm H}α}-β$ is a bi-modal relationship, characterised by two peaks: concentration of the star forming regions at a positive $β$ (rising CVC) and another one of the retired regions with a negative $β$ (declining CVC). Our results show that both the amplitude of the CVC, driven by the mass of the galaxies, and the shape of the CVC, reflecting the internal structure of the galaxies, play an important role in galaxy's quenching history.

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