Galaxy morphology in the LambdaCDM cosmology

@misc{citeulike:2935288, abstract = {We investigate the origins of galaxy morphology (defined by bulge-to-total B-band luminosity) in the LambdaCDM cosmology using two galaxy formation models based on the Millennium simulation, one by Bower et al. (the Durham model) and the other by De Lucia \& Blaizot (the MPA model). Both models have had considerable success in reproducing a number of observed properties of the local and high redshift universe, including star formation rates, the stellar mass function and the luminosity function out to z \~{} 5. There are many similarities, but also fundamental disagreements in the predictions of the two models for galaxy morphology. For example, both produce a realistic morphological mix today, but its evolution is very different. A main cause of this and other differences is the treatment of disk instabilities which play a more prominent role in the Durham model. Our analysis confirms previous theoretical predictions that elliptical galaxies form most of their stars before the bulk of the galaxy is assembled. Spirals tend to have later `assembly' times than ellipticals as a consequence of in-situ star formation. With the exception of the brightest ellipticals (stellar mass \> 2.5*10^11 h^-1 M\_sun), we find that major mergers are not the primary mechanism by which most spheroids (ellipticals and spiral bulges) assemble their mass. In fact, the majority of ellipticals (and the overwhelming majority of spirals) never experience a major merger (above the resolution limit of our simulation.) Most ellipticals and spiral bulges acquire their stellar mass through minor mergers or disk instabilities. These conclusions are common to both the MPA and Durham models. The rotation properties of spheroids offer an important observational test of these models.}, author = {Parry, O. H. and Eke, V. R. and Frenk, C. S. }, citeulike-article-id = {2935288}, eprint = {0806.4189}, month = {Jun}, posted-at = {2008-06-27 12:20:04}, priority = {2}, title = {Galaxy morphology in the LambdaCDM cosmology}, url = {http://arxiv.org/abs/0806.4189}, year = {2008} }

TY - ELEC ID - citeulike:2935288 L3 - citeulike-article-id:2935288 TI - Galaxy morphology in the LambdaCDM cosmology N2 - We investigate the origins of galaxy morphology (defined by bulge-to-total B-band luminosity) in the LambdaCDM cosmology using two galaxy formation models based on the Millennium simulation, one by Bower et al. (the Durham model) and the other by De Lucia & Blaizot (the MPA model). Both models have had considerable success in reproducing a number of observed properties of the local and high redshift universe, including star formation rates, the stellar mass function and the luminosity function out to z ~ 5. There are many similarities, but also fundamental disagreements in the predictions of the two models for galaxy morphology. For example, both produce a realistic morphological mix today, but its evolution is very different. A main cause of this and other differences is the treatment of disk instabilities which play a more prominent role in the Durham model. Our analysis confirms previous theoretical predictions that elliptical galaxies form most of their stars before the bulk of the galaxy is assembled. Spirals tend to have later `assembly' times than ellipticals as a consequence of in-situ star formation. With the exception of the brightest ellipticals (stellar mass > 2.5*10^11 h^-1 M_sun), we find that major mergers are not the primary mechanism by which most spheroids (ellipticals and spiral bulges) assemble their mass. In fact, the majority of ellipticals (and the overwhelming majority of spirals) never experience a major merger (above the resolution limit of our simulation.) Most ellipticals and spiral bulges acquire their stellar mass through minor mergers or disk instabilities. These conclusions are common to both the MPA and Durham models. The rotation properties of spheroids offer an important observational test of these models. AU - Parry, OH AU - Eke, VR AU - Frenk, CS PY - 2008/Jun/26/ UR - http://arxiv.org/abs/0806.4189 ER -