Thursday, April 11, 2013

1304.2770 (Ignacio Ferreras et al.)

Age-dating the Tully-Fisher relation at moderate redshift    [PDF]

Ignacio Ferreras, Asmus Böhm, Bodo Ziegler, Joseph Silk
We analyse the Tully-Fisher relation at moderate redshift from the point of view of the underlying stellar populations, by comparing optical and NIR photometry with a phenomenological model that combines population synthesis with a simple prescription for chemical enrichment. The sample comprises 108 late-type galaxies extracted from the FORS Deep Field (FDF) and William Herschel Deep Field (WHDF) surveys at z<1 (median redshift z=0.45). A strong correlation is found between stellar mass and the parameters that describe the star formation history, with massive galaxies forming their populations early (zFOR~3), with star formation timescales, tau1~4 Gyr; although with very efficient chemical enrichment timescales (tau2~1 Gyr). In contrast, the stellar-to-dynamical mass ratio which, in principle, would track the efficiency of feedback in the baryonic processes driving galaxy formation - does not correlate strongly with the model parameters. On the Tully-Fisher plane, no significant age segregation is found at fixed circular speed, whereas at fixed stellar-to-dynamical mass fraction, age splits the sample, with older galaxies having faster circular speeds at fixed Ms/Mdyn. Although our model does not introduce any prior constraint on dust reddening, we obtain a strong correlation between colour excess and stellar mass.
View original: http://arxiv.org/abs/1304.2770

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