Scientific Highlights

Integral-field spectroscopy reveals the physics of intestellar medium during ram-pressure stripping

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Integral-field spectroscopy together with N-body/hydrodynamical simulations explain gas kinematics during ram-pressure stripping

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Using integral-field spectroscopy and simulations to understand ram-pressure stripping

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A new class of transition galaxies in the process of being transformed from star-forming to passive

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Global star formation in the Shapley supercluster

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The nature of star formation in clusters

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Bimodality in infrared colour distribution

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Multi-wavelength Luminosity Functions

Many of the processes (e.g. gas-stripping, harassment, starvation) that drive the evolution of galaxies also shape the luminosity function (LF), one of the most basic and fundamental properties of the galaxy population (Benson et al. 2003). The distributions of galaxy luminosities of cluster galaxies at various wavelengths can hence provide quantitative probes of how these dense environments affect the fundamental galaxy properties such as the overall mass function, stellar masses and SFRs.

A key question is whether the LF shows a significant environmental dependence or is instead universal. This remains unclear, with some studies suggesting relatively little variation with environment (e.g. de Propris et al. 1998; Christlein & Zabludoff 2003; Rines & Geller 2008), while other find significant differences including brighter characteristic luminosities and steeper faint-end slopes (e.g. Popesso et al. 2005), which could be largely ascribed to the diverse morphological composition of cluster and field populations (de Lapparent 2003).

 

Near Infrared LF

 

 

Origins of the scatter of the Fundamental Plane

In the study of the Fundamental Plane of early-type galaxies in the core of the Shapley supercluster, we found that the residuals to the Fundamental Plane are anti-correlated both with the alpha-element abundance ratio alpha/Fe and with galaxy age. Galaxies which are more compact with respect to the FP have stellar populations older and higher α/Fe abundance than average. This result is consistent with the idea that earlier mergers, with higher initial gas fractions, triggered more centrally concentrated and shorter bursts of star formation.