All Figures

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{0626f001.ps} \end{figure}$ Figure 1: Galaxy stellar masses in the K20 sample as a function of redshift. Upper panel: estimates based on Maximal Age model. Lower panel: estimates based on the Best Fit method. Filled circles: early type galaxies; empty circles: early+emission type; crosses: "star-forming'' type; triangles: objects with photometric redshifts. A few very low redshift objects at $M_*<7\times 10^{8}~M_\odot$ are omitted. The short and long dashed lines correspond to the completeness threshold, define by computing a maximally massive model with $K_{\rm s}=20$ , considering dust and dust-free models, respectively (see text for details). Solid lines correspond to the selection curves that we have applied when building the Galaxy Stellar Mass Function, after application of the appropriate correction for incompleteness as described in Sect. 5 and Appendix B.
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In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0626f002.ps} \end{figure}$ Figure 2: M_*/L_R ratios as a function of redshift, in the K20 sample. Upper panel shows the Maximal Age estimates, while lower one shows the Best Fit ones. In both panels the symbols correspond to different spectral types, as in Fig. 1.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0626f003.ps} \end{figure}$ Figure 3: M_*/L_R ratios as a function of redshift for spectroscopically early and early+emission spectral type galaxies of the K20 sample. Large hollow circles are for bright (M_R<-22) objects, small filled circles for fainter (M_R>-22) ones. Lines show the M_*/L_R values computed with a set of single-exponential models with $z_{\rm form}=3$ (thin lines) or $z_{\rm form}=20$ (thick lines) and star-formation time-scales ranging of $\tau = 0.1$ Gyr (dashed lines) and $\tau = 3$ Gyr (solid lines), all drawn with a Salpeter IMF and no dust extinction.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=15cm,clip]{0626f004.ps} \end{figure}$ Figure 4: Galaxy stellar mass functions in the K20 sample, in four redshift ranges. Different symbols correspond to different methods adopted to estimate the stellar mass: triangles represent the Maximal Age estimates, and squares the Best Fit estimates. In the highest redshift bin, large hollow circles correspond to the GSMF measured by using only objects with spectroscopic redshift. Thick lines correspond to local galaxy mass functions: the solid line is the local galaxy mass function by Cole et al. (2001), the dot-dashed one is the same GSMF renormalized to our "BF'' method (See text and Appendix A for details). The same line types have been used to represent the Schechter fits to our "extended'' galaxy mass functions (thin lines).
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{0626f005.ps} \end{figure}$ Figure 5: Ratio between the observed Galaxy Stellar Mass Functions in the K20 sample and the local GSMF. Data points refer to the ratio of the "Best Fit'' values to the corresponding "rescaled'' local GSMF. Filled symbols refer to points at z<1.0 (squares: 0.2<z<0.7; triangles 0.7<z<1.0); open symbols to z>1.0 (diamonds: 1.0<z<1.5, squares: 1.5<z<2). The data points at 1.5<z<2include objects with photometric redshifts.
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In the text

$\begin{figure} \par\includegraphics[width=8.6cm,clip]{0626f006.ps} \end{figure}$ Figure 6: Galaxy stellar mass functions in the K20 sample for different spectral types. Empty points correspond to late spectral type, filled to early spectral type. The solid lines show the Schechter fits to the total GSMF of our sample at the corresponding redshifts.
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In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{0626f007.ps} \end{figure}$ Figure 7: Evolution of the cosmological mass density as a function of redshift. Upper panel: observed cosmological mass density as observed in the K20 data. Squares correspond to BF estimates, Triangles to MA estimates. Empty points represent the observed values, with the corresponding Poisson noise. Filled points represent the values corrected for incompleteness, as obtained by integrating the mass function over the whole range $10^{8}~ M_\odot \leq M_* \leq 10^{13} ~M_\odot$ . Error bar are computed from the uncertainties in the best-fit parameters of the Schechter Function. Lower panel: The global evolution of the cosmological mass density from z=0 to z=3 as observed from the K20 and other surveys. Filled points represent the total values from the K20 survey: squares are the "Best Fit'' values and triangles the "Maximal Age'' estimates. The points at $\langle z \rangle =2.25$ are lower limit since they are affected by incompleteness. The large open triangle is the local value by Cole et al. (2001), while the large open square is the same local value rescaled to the BF technique. Open exagones are from Cohen et al. (2001), open triangles from Brinchmann & Ellis (2000), open squares from D03, diamonds from F03, empty circles from Glazebrook et al. (2004). Error bars in the latter two surveys take into account for the systematic uncertainties among the methods adopted, as in the case of our MA and BF approaches. The two lines are the mass densities expected by integrating the star formation histories of Steidel et al. (1999) for two different extinction coefficients (dashed: E(B-V)=0; solid: E(B-V)=0.15).
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0626f008.ps} \end{figure}$ Figure 8: Observed Galaxy Stellar Mass Functions in the K20 sample, compared with the baryonic mass function in a $\Lambda$ -CDM hierarchical scenarios and with PLE predictions for the galaxy stellar mass function. The redshift ranges and symbols are the same as in Fig. 4. In particular, hollow circles represent the stellar mass function computed only on the sample with spectroscopic redshifts. The solid line is the theoretical estimate of the Galaxy Baryonic Mass Function, that is to be regarded as an upper limit in $\Lambda$ -CDM scenarios. The dashed line is the GSMF predicted by PLE models.
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In the text

$\begin{figure} \par\includegraphics[angle=-90,width=15cm,clip]{0626f009.ps} \end{figure}$ Figure 9: Observed Galaxy Stellar Mass Functions in the K20 sample, compared with theoretical rendition in a $\Lambda$ -CDM hierarchical Universe, divided according to the IMF adopted in the models. Left panel: Salpeter (1955); central panel: Gould et al. (1996), right panel: Kennicutt (1983). In the central and right panels the observed GSMFs have been scaled to the corresponding IMF as described in the text. The theoretical models are: left panel: Menci et al. (2002) (dashed line) and Menci et al. (2004) (solid line); central panel: Nagamine et al. (2001); right panel: Cole et al. (2000) (short-dashed); Somerville et al. (2004a) (S04 and S04b, thick solid and dashed lines); Granato et al. (2004) (dot-dashed). See text for full details. All the model predictions are evaluated at the central redshift of each bin, with the exception of the Nagamine et al. (2001) case which is computed at z=0.5, 1 and 2.
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In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0626f010.ps} \end{figure}$ Figure 10: Cosmological Stellar Mass Density for objects of $M_* \simeq 10^{11}~M_\odot$ in the K20 survey, compared with the theoretical models discussed in the text, divided according to the relevant IMF: upper panel: Salpeter (1955); central panel: Gould et al. (1996); lower panel: Kennicutt (1983). Filled squares represent the BF estimates, filled triangles the MA estimates. The empty circle at z=0.1 represents the local value of Cole et al. (2001), the empty square the same value "scaled'' to BF (see text for details). The models plotted are: Menci et al. (2002) (M02, long dashed line), Menci et al. (2004) (M04, solid line) and PLE (short-dashed line) in the upper panel; Nagamine et al. (2001) (N01, solid line) in the central panel, and Cole et al. (2000) (C00, short-dashed); Somerville et al. (2004a) (S04a and S04b, thick solid and dashed lines); Granato et al. (2004) (dot-dashed line). See text for more details. The relative value with respect to the local value of Cole et al. (2001) is shown in the right y-axis.
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In the text

$\begin{figure} \par\includegraphics[width=7.9cm,clip]{0626fga1.ps} \end{figure}$ Figure A.1: Comparison between the stellar masses estimated for the K20 galaxies with the Maximal Age and Best Fit techniques. Upper panel: the relation between MA (x-axis) and BF (y-axis) stellar masses in the K20 sample with full multicolor coverage. Different symbol refer to spectroscopic classification, as in Fig. 1: solid circles, early type; empty circles, early+emission type; crosses, late type; triangles, photometric redshifts. The dashed line shows the first-order fit to the observed relation. Lower panel: ratio between the MA and BF sample as a function of the redshift, for the same sample. Symbols have the same meaning of the upper panel.

In the text

$\begin{figure} \par\includegraphics[width=8.3cm,clip]{0626fga2.ps} \end{figure}$ Figure A.2: Results of the simulations performed to check the reliability of the Best Fit stellar mass estimates in the cases of star-formation histories characterized by multiple starbursts. The histogram shows the ratio between the fitted mass $M_{\rm fit}$ and the input one $M_{\rm input}$ at three different ages of the second starburst. The solid line shows the results of the simulations done assuming that the second starburst assembles a fraction f from 10% to 70% of the total mass. Thin solid line is the simulation with f=10%. Dashed line shows a simulation with the starburst component only.

In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0626fga3.ps} \end{figure}$ Figure A.3: Comparison between the D4000 break measured from the K20 spectroscopic observations (x-axis) and the D4000 break estimated from the Best Fit models (y-axis). Filled dots represent late-type galaxies while crosses the star-forming ones.

In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{0626fga4.ps} \end{figure}$ Figure A.4: Confidence levels on the estimated BF mass, as a function of K-band magnitude ( upper panel) and redshift ( lower panel). The confidence level $\Delta M_*$ is defined as $\Delta M_* = (M_{\rm max} - M_{\rm min})/2 M_{\rm best}$ Filled points represent objects with spectroscopic redshift, empty with photometric redshifts.

In the text

$\begin{figure} \par\includegraphics[width=8.3cm,clip]{0626fga5.ps} \end{figure}$ Figure A.5: A comparison between the stellar masses estimated with the Maximal Age and with the Best Fit methods on 6500 galaxies at $z\simeq 0.1$ taken from the SDSS and 2MASS surveys. Solid line is the $M_{\rm BF}=M_{\rm MA}$ locus, dashed line is the linear regression among the observed points.

In the text

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{0626fgb1.ps} \end{figure}$ Figure B.1: Relation between the observed $K_{\rm s}$ flux (lower scale; in the upper scale, the corresponding $K_{\rm s}$ magnitude) and the BF estimated stellar masses, at $z\simeq 0.7$ . Filled points are taken from the K20 sample, empty are taken from the HDFS sample (F03) for comparison only. The diagonal lines bracket the whole range of masses that are allowed to galaxies of the corresponding $K_{\rm s}$ magnitude in the BF model grid. The solid line show the minimal mass for objects of given flux. The dashed line is the maximal mass, if one takes into account dusty objects, while the dashed-dotted line is the maximal mass for dust-free, passively evolving objects. The dashed vertical line shows the $K_{\rm s}<20$ limit of the K20 survey. The dotted line show the resulting (strict) completeness limit on stellar masses, according to the selection curve adopted. The shaded area shows the fraction of galaxies lost (at a given mass) by incomplete coverage of the M_*/L ratio.

In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0626fgb2.ps} \end{figure}$ Figure B.2: Effect of the correction for incompleteness on the Galaxy Stellar Mass Function in two redshift bins. Empty circles represent the GSMF computed on strictly mass-complete samples, while filled squares represent the GSMF computed on the "extended'' sample with the correction for incompleteness applied, and solid line is the corresponding Schechter fit. Triangles show the GSMF computed on the "extended'' sample without any correction for incompleteness, and dashed line the corresponding Schechter fit.

In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0626f002.ps} \end{figure}$	Figure 2: M_*/L_R ratios as a function of redshift, in the K20 sample. Upper panel shows the Maximal Age estimates, while lower one shows the Best Fit ones. In both panels the symbols correspond to different spectral types, as in Fig. 1.
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$\begin{figure} \par\includegraphics[width=8.6cm,clip]{0626f006.ps} \end{figure}$	Figure 6: Galaxy stellar mass functions in the K20 sample for different spectral types. Empty points correspond to late spectral type, filled to early spectral type. The solid lines show the Schechter fits to the total GSMF of our sample at the corresponding redshifts.
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