Roberto Rampazzo

Main Research field: study of (Es+S0s= ETGs) in low density environments (LDE): + A catalogue of candidates of isolated pairs of galaxies in the southern hemisphere (Reduzzi & Rampazzo 1995) has been produced. The catalog is still used from several teams to study galaxy-galaxy interaction and their effects (e.g. SNae rates). + CO observations of 51 gas rich pair members. CO luminosity is enhanced in tidally perturbed galaxies. Evidence was found that the main phenomenon triggering star formation is the enhancement in the total amount of molecular gas likely induced by gas inflow during the tidal interaction (Combes, Prugniel, Rampazzo & Sulentic 1994). Later, Fabry-Perot observations of interacting gas rich pairs provide direct evidence of ionized gas flows towards the galaxy nuclei and cross-fueling mechanisms in action between galaxies during intepenetaring encounters (Rampazzo et al. 2005; Rampazzo et al. 2006). CO seems to maintain a better organized motion with respect to the warm ionized gas. + The pair catalogue has been used to compare the rate of occurrence of fine structures between `isolated' and paired ETGs. The rate of occurrence in LDE ETGs is significantly higher than that that found for pairs (Reduzzi, Longhetti & Rampazzo 1996). Interactions tend to cancel fine structures (e.g. shells) created by mergers and/or week interaction phenomena. + The measure of Lick line-strength indices and the Hbeta-[MgFe] analysis was, for the first time, applied to a sample of 51 ETGs pair members and shell galaxies in LDE. The study leads to the concept of "re-juvenation" of the ETGs nucleus (Longhetti, Bressan, Chiosi & Rampazzo 2000 and reference therein) due to a recent episode of star formation. This concept is now widely accepted. + With a large observing campaign, spectra of 65 southern ETGs with emission lines, mostly in LDE, were obtained and analyzed deriving Lick line-strength indices in luminosity weighted apertures and gradients at different galacto-centric radii (Rampazzo, Annibali, Bressan et al. 2005). Underlying stellar populations are studied deriving ages, metallicities gradients and [alpha/Fe] enhancements (Annibali, Bressan, Rampazzo, Zeilinger, Danese 2007). A large spread in age is measured, with SSP-equivalent ages ranging from a few to the age of the Universe. Since the ETGs age seems to correlate with the galaxy density we used these studies to calibrate line-strength indices for 14000 ETGs from SDSS. ETGs in LDE result 20% younger of their cluster counterparts at every range of mass (Clemens, Bressan, Nikolic & Rampazzo 2009; see also Clemens et al. 2006). + Spitzer-IRS observations of a sub-sample of the above 65 ETGs show a large presence of Polycyclic Aromatic Hydrocarbons (PAHs) confirming recent nuclear star formation activity. However, only a small fraction shows on-going star formation (Panuzzo, Rampazzo, Bressan, Vega et al. 2011). Mid-Infrared spectra can be organized according into a small number of classes. We suggest that spectral MIR classes map the nucleus evolutionary phases (from passive to star forming, AGN activity, erosion of PAHs) during an accretion episode. - GALEX observations of a sub-sample of the above ETGs confirm recent nuclear star formation activity (Rampazzo, Marino, Tantalo, Bettoni et al. 2007; Marino, Rampazzo, Bianchi et al. 2011). In a subsample of S0s with ring-like structures the star formation is extended to the disk (Marino, Bianchi, Rampazzo, Thilker et al. 2011) and populate the Green Valley in the (NUV-r)-M_r plane. + Recent results in the web-site http://web.oapd.inaf.it/rampazzo/