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UniMass - Chiara Tonini

I am a post-doctoral researcher within the UNIMASS Excellence Grant team project (PI Claudia Maraston). The aim of the project is to understand galaxy formation and evolution through modeling and data analysis based on up-to-date stellar population models. In this framework, I use a semi-analytic model (GalICS) to predict the properties of high-redshift galaxies, like luminosities, colors, and dynamics. The use of the Maraston (2005) stellar populations, which include a full treatment of the Thermally Pulsing Asymptotic Giant Branch phase of stellar evolution, allow the model to agree with the data and to reproduce for the first time the near-IR colours and luminosities of massive distant galaxies. In addition, for the first time the model now matches the zero-point and slope of the near-IR Tully-Fisher relation at high redshift. These studies are important to understand the mass assembly history of galaxies, their star formation rate across cosmic time, and the role of mergers and feedback in shaping the galaxy structure. This work aims at contributing to a unified picture of galaxy formation in the hierarchical clustering scenario.


The theoretical colour-magnitude relation Irac3 vs H-Irac3 at z=2, corresponding to the rest-frame K vs V-K, for the star-forming galaxies in the M05 run (left panel) and the PEGASE run (right panel), compared with data.
The black dots with errorbars are data points from the GOODS-S catalogue (Daddi et al. 2007).
In both panels, the results are shown for runs with reddening (a Calzetti-type extinction with colour-excess proportional to the SFR; cyan and magenta dots) and without reddening (blue and green dots).



The colour-colour relation J-H vs H-Irac3 at z=2, corresponding to the rest frame B-V vs V-K, for the M05 run (left panel) and the PEGASE run (right panel). The black dots with errorbars are data points from the GOODS catalogue (Daddi et al. 2007). The green triangles with errorbars are data from Maraston et al. (2006) of nearly-passively evolving galaxies.
For the M05 run, the red dots represent nearly-passive galaxies (SFR<3 M/yr) and cyan dots represent the star-forming galaxies (SFR>10 M/yr); in the PEGASE run, the same holds for yellow/magenta dots respectively.



The rest-frame K-band luminosity function of the M05 (thick red line) and PEGASE (thick cyan line) runs, compared with published LFs in the literature: Bower et al. 2006 (solid), Cole et al. 2000 (\short-dashed), Baugh et al. 2005 (dotted), Menci et al. 2006 (long dot-dashed), Monaco et al. 2007 (short dot-dashed) and De Lucia & Blaizot (2007) (long-dashed).

Publications within the UNIMASS project:
Hierarchical models of high redshift galaxies with thermally pulsing asymptotic giant branch stars: comparison with observations, Tonini C., Maraston C., Thomas D., Devriendt J., Silk J., Monthly Notices of the Royal Astronomical Society, 2010, MNRAS,403,1749T
The impact of thermally pulsing asymptotic giant branch stars on hierarchical galaxy formation models, Tonini C., Maraston C., Devriendt J., Thomas D., Silk J., Monthly Notices of the Royal Astronomical Society: Letters, Volume 396, Issue 1, pp. L36-L40.
Star formation rates and masses of z ~ 2 galaxies from multicolour photometry, Maraston C., Pforr, J., Renzini, A., Daddi, E., Dickinson, M., Cimatti, A., Tonini, C., 2010arXiv1004.4546M
The role of stellar populations on the predicted evolution of the Tully-Fisher relation, Tonini C., Maraston C., Devriendt J., Thomas D., Silk J., Bohm A., Ziegler B., in preparation

RESOURCES
Mock galaxy catalogues with GalICS: magnitudes and spectra