TY - GEN
T1 - The star-formation histories of early-type galaxies from ATLAS3D
AU - McDermid, Richard M.
AU - Alatalo, Katherine
AU - Blitz, Leo
AU - Bois, Maxime
AU - Bournaud, Frédéric
AU - Bureau, Martin
AU - Cappellari, Michele
AU - Crocker, Alison F.
AU - Davies, Roger L.
AU - Davis, Tim A.
AU - de Zeeuw, P. T.
AU - Duc, Pierre-Alain
AU - Emsellem, Eric
AU - Khochfar, Sadegh
AU - Krajnović, Davor
AU - Kuntschner, Harald
AU - Lablanche, Pierre-Yves
AU - Morganti, Rafaella
AU - Naab, Thorsten
AU - Oosterloo, Tom
AU - Sarzi, Marc
AU - Scott, Nic
AU - Serra, Paolo
AU - Weijmans, Anne-Marie
AU - Young, Lisa M.
N1 - M1 - Conference Proceedings
PY - 2012/8
Y1 - 2012/8
N2 - We present an exploration of the integrated stellar populations of early-type galaxies (ETGs) from the ATLAS3D survey. We use two approaches: firstly the application of line-indices interpreted through single stellar population (SSP) models, which provide a single value of age, metallicity and abundance ratio. And secondly, by fitting a linear combination of SSP spectra to our data, smoothly weighted in the free parameters of age and metallicity, thereby inferring a star-formation history of these galaxies. Despite the significant differences in these approaches, we obtain generally consistent results, such that galaxies that are more massive appear older with enhanced abundance ratios using line indices, and have shorter star-formation histories weighted to early times. We highlight two limitations of the index-SSP approach. Firstly the SSP-equivalent ages belie the fact that ETGs are overwhelmingly composed of ancient stars. Secondly, the young stellar contributions implied in our star formation histories are required to obtain realistic UV-optical colours. We remark that, even fitting solar-abundance models, we can recover a star-formation duration that correlates with the measured alpha-enhancement, in agreement with other recent work.
AB - We present an exploration of the integrated stellar populations of early-type galaxies (ETGs) from the ATLAS3D survey. We use two approaches: firstly the application of line-indices interpreted through single stellar population (SSP) models, which provide a single value of age, metallicity and abundance ratio. And secondly, by fitting a linear combination of SSP spectra to our data, smoothly weighted in the free parameters of age and metallicity, thereby inferring a star-formation history of these galaxies. Despite the significant differences in these approaches, we obtain generally consistent results, such that galaxies that are more massive appear older with enhanced abundance ratios using line indices, and have shorter star-formation histories weighted to early times. We highlight two limitations of the index-SSP approach. Firstly the SSP-equivalent ages belie the fact that ETGs are overwhelmingly composed of ancient stars. Secondly, the young stellar contributions implied in our star formation histories are required to obtain realistic UV-optical colours. We remark that, even fitting solar-abundance models, we can recover a star-formation duration that correlates with the measured alpha-enhancement, in agreement with other recent work.
KW - galaxies: elliptical and lenticular
KW - cD
KW - evolution
KW - formation
KW - stellar content
U2 - 10.1017/S1743921312009167
DO - 10.1017/S1743921312009167
M3 - Conference contribution
T3 - Proceedings of the International Astronomical Union
SP - 244
EP - 247
BT - The Spectral Energy Distribution of Galaxies
PB - Cambridge University Press
ER -