%0 Generic %1 Cappellari2012 %A Cappellari, Michele %A McDermid, Richard M. %A Alatalo, Katherine %A Blitz, Leo %A Bois, Maxime %A Bournaud, Frederic %A Bureau, M. %A Crocker, Alison F. %A Davies, Roger L. %A Davis, Timothy A. %A de Zeeuw, P. T. %A Duc, Pierre-Alain %A Emsellem, Eric %A Khochfar, Sadegh %A Krajnovic, Davor %A Kuntschner, Harald %A Lablanche, Pierre-Yves %A Morganti, Raffaella %A Naab, Thorsten %A Oosterloo, Tom %A Sarzi, Marc %A Scott, Nicholas %A Serra, Paolo %A Weijmans, Anne-Marie %A Young, Lisa M. %D 2012 %K imf variation %T A systematic variation of the stellar initial mass function in early-type galaxies %U http://arxiv.org/abs/1202.3308 %X Much of our knowledge of galaxies comes from analysing the radiation emitted by their stars. It depends on the stellar initial mass function (IMF) describing the distribution of stellar masses when the population formed. Consequently knowledge of the IMF is critical to virtually every aspect of galaxy evolution. More than half a century after the first IMF determination, no consensus has emerged on whether it is universal in different galaxies. Previous studies indicated that the IMF and the dark matter fraction in galaxy centres cannot be both universal, but they could not break the degeneracy between the two effects. Only recently indications were found that massive elliptical galaxies may not have the same IMF as our Milky Way. Here we report unambiguous evidence for a strong systematic variation of the IMF in early-type galaxies as a function of their stellar mass-to-light ratio, producing differences up to a factor of three in mass. This was inferred from detailed dynamical models of the two-dimensional stellar kinematics for the large Atlas3D representative sample of nearby early-type galaxies spanning two orders of magnitude in stellar mass. Our finding indicates that the IMF depends intimately on a galaxy's formation history.

@misc{Cappellari2012, abstract = { Much of our knowledge of galaxies comes from analysing the radiation emitted by their stars. It depends on the stellar initial mass function (IMF) describing the distribution of stellar masses when the population formed. Consequently knowledge of the IMF is critical to virtually every aspect of galaxy evolution. More than half a century after the first IMF determination, no consensus has emerged on whether it is universal in different galaxies. Previous studies indicated that the IMF and the dark matter fraction in galaxy centres cannot be both universal, but they could not break the degeneracy between the two effects. Only recently indications were found that massive elliptical galaxies may not have the same IMF as our Milky Way. Here we report unambiguous evidence for a strong systematic variation of the IMF in early-type galaxies as a function of their stellar mass-to-light ratio, producing differences up to a factor of three in mass. This was inferred from detailed dynamical models of the two-dimensional stellar kinematics for the large Atlas3D representative sample of nearby early-type galaxies spanning two orders of magnitude in stellar mass. Our finding indicates that the IMF depends intimately on a galaxy's formation history. }, added-at = {2012-02-16T23:29:13.000+0100}, author = {Cappellari, Michele and McDermid, Richard M. and Alatalo, Katherine and Blitz, Leo and Bois, Maxime and Bournaud, Frederic and Bureau, M. and Crocker, Alison F. and Davies, Roger L. and Davis, Timothy A. and de Zeeuw, P. T. and Duc, Pierre-Alain and Emsellem, Eric and Khochfar, Sadegh and Krajnovic, Davor and Kuntschner, Harald and Lablanche, Pierre-Yves and Morganti, Raffaella and Naab, Thorsten and Oosterloo, Tom and Sarzi, Marc and Scott, Nicholas and Serra, Paolo and Weijmans, Anne-Marie and Young, Lisa M.}, biburl = {https://www.bibsonomy.org/bibtex/266e114a2b2db5cf71f5c4d5aa9af5033/miki}, description = {[1202.3308] A systematic variation of the stellar initial mass function in early-type galaxies}, interhash = {e3f1dc402b4f66d400ed9e8a46b8fa73}, intrahash = {66e114a2b2db5cf71f5c4d5aa9af5033}, keywords = {imf variation}, note = {cite arxiv:1202.3308 Comment: 4 pages, 2 figures, LaTeX. Accepted for publication as a Nature Letter. More information about our Atlas3D project is available at http://purl.org/atlas3d}, timestamp = {2012-02-16T23:29:13.000+0100}, title = {A systematic variation of the stellar initial mass function in early-type galaxies}, url = {http://arxiv.org/abs/1202.3308}, year = 2012 }