Two phase formation of massive elliptical galaxies : study through   cross-correlation including spatial effect
  Formation mechanism of present day population of elliptical galaxies have been revisited in the context of hierarchical cosmological models accompanied by accretion and minor mergers through cross correlation function including spatial effect. The present work investigates the formation and evolution of several components of nearby massive early type galaxies (ETGs) through cross-correlation in the spatial coordinates, right ascension and declination (RA, DEC) and mass-size parameter space with high redshift $(0.5\leq z\leq2.7)$ ETGs. It is found that innermost components of nearby ETGs are highly correlated with ETGs in the redshift range $(2\leq z\leq2.7)$ known as 'red nuggets'. The intermediate and outermost parts have moderate correlations with ETGs in the redshift range $(0.5\leq z\leq0.75)$. The quantitative measures are highly consistent with the two phase formation scenario of massive nearby early type galaxies as suggested by various authors and resolves the conflict raised in a previous work suggesting other possibilities for the formation of outermost part of nearby massive ETGs. The improvement is expected to be due to inclusion of spatial effects in addition to other linear parameters. 
Soumita Modak, Tanuka Chattopadhyay and Asis Kumar Chattopadhyay
astro-ph.GA