Context. Star formation rate (SFR), metallicity, and stellar mass are among the most important parameters of star-forming (SF) galaxies characterizing their formation and evolution. They are known to be related to each other both at low and high redshift in the mass-metallicity, mass-SFR, and metallicity-SFR relations. Aims. We demonstrate the existence of a plane in a 3D parameter space defined by the axes SFR [log (SFR)(M yr −1 )], gas metallicity [12 + log (O/H)], and stellar mass [log (M star /M )] of SF galaxies. Methods. We used SF galaxies from the "main galaxy sample" of the Sloan Digital Sky Survey-Data Release 7 (SDSS-DR7) in the redshift range 0.04 < z < 0.1 and r-magnitudes between 14.5 and 17.77. Metallicities, SFRs, and stellar masses were taken from the Max-Planck-Institute for Astrophysics-John Hopkins University (MPA-JHU) emission-line analysis database. Results. From a final sample of 32 575 galaxies, we find for the first time a fundamental plane for field galaxies relating the SFR, gas metallicity, and stellar mass for SF galaxies in the local universe. One of the applications of this plane would be to estimate stellar masses from SFR and metallicity. High redshift data from the literature at redshift ∼0.85, 2.2, and 3.5, do not show evidence of evolution in this fundamental plane.

The ALHAMBRA (Advance Large Homogeneous Area Medium Band Redshift Astronomical) survey has observed 8 different regions of the sky, including sections of the COSMOS, DEEP2, ELAIS, GOODS-N, SDSS and Groth fields using a new photometric system with 20 optical, contiguous ∼300Å filters plus the JHKs bands. The filter system is designed to optimize the effective photometric redshift depth of the survey, while having enough wavelength resolution for the identification of faint emission lines. The observations, carried out with the Calar Alto 3.5m telescope using the wide field optical camera LAICA and the NIR instrument Omega-2000, represent a total of ∼700hrs of on-target science images. Here we present multicolor PSF-corrected photometry and photometric redshifts for ∼438,000 galaxies, detected in synthetic F 814W images. The catalogs are complete down to a magnitude I∼24.5AB and cover an effective area of 2.79 deg 2 . Photometric zeropoints were calibrated using stellar transformation equations and refined internally, using a new technique based on the highly robust photometric redshifts measured for emission line galaxies. We calculate Bayesian photometric redshifts with the BPZ2.0 code, obtaining a precision of δ z /(1+z s )=1% for I<22.5 and δ z /(1+z s )=1.4% for 22.5=0.56 for I<22.5 AB and =0.86 for I<24.5 AB. Given its depth and small cosmic variance, ALHAMBRA is a unique dataset for galaxy evolution studies.

We study the dependence of the galaxy size evolution on morphology, stellar mass and large scale environment for a sample of 298 group and 384 field quiescent earlytype galaxies from the COSMOS survey, selected from z ∼ 1 to the present, and with masses log(M/M ⊙ ) > 10.5.From a detailed morphological analysis we infer that ∼ 80% of passive galaxies with mass log(M/M ⊙ ) > 10.5 have an early-type morphology and that this fraction does not evolve over the last 6 Gyr. However the relative abundance of lenticular and elliptical galaxies depends on stellar mass. Elliptical galaxies dominate only at the very high mass end -log(M/M ⊙ ) > 11 -while S0 galaxies dominate at lower stellar masses -10.5 < log(M/M ⊙ ) < 11.The galaxy size growth depends on galaxy mass range and early-type galaxy morphology, e.g., elliptical galaxies evolve differently than lenticular galaxies. At the low mass end -10.5 < Log(M/M ⊙ ) < 11, ellipticals do not show strong size growth from z ∼ 1 to the present (10% to 30% depending on the morphological classification). On the other end, massive ellipticals -log(M/M ⊙ ) > 11.2 -approximately doubled their size. Interestingly, lenticular galaxies display different behavior: they appear more compact on average and they do show a size growth of ∼ 60% since z = 1 independent of stellar mass range.We compare our results with state-of-the art semi-analytic models. While major and minor mergers can account for most of the galaxy size growth, we find that with present data and the theoretical uncertainties in the modeling we cannot state clear evidence favoring either merger or mass loss via quasar and/or stellar winds as the primary mechanism driving the evolution.The galaxy mass-size relation and size growth do not depend on environment in the halo mass range explored in this work (field to group mass log(M h /M ⊙ ) < 14), i.e., group and field galaxies follow the same trends. At low redshift, where we examine both SDSS and COSMOS groups, this result is at variance with predictions from some current hierarchical models that show a clear dependence of size growth on halo mass for massive ellipticals ( log(M * /M ⊙ ) > 11.2). In future work we will analyze in detail if this result is specific of the observations and model used in this work.BCG and satellite galaxies lie on the same mass-size relation, at variance with predictions from hierarchical models, which predict that BCGs should have larger sizes than satellites because they experience more mergers in groups over the halo mass range probed.

Dust-enshrouded, starbursting, submillimeter galaxies (SMGs) at z3 have been proposed as progenitors of z2 compact quiescent galaxies (cQGs). To test this connection, we present a detailed spatially resolved study of the stars, dust, and stellar mass in a sample of six submillimeter-bright starburst galaxies at z∼4.5. The stellar UV emission probed by HST is extended and irregular and shows evidence of multiple components. Informed by HST, we deblend Spitzer/ IRAC data at rest-frame optical, finding that the systems are undergoing minor mergers with a typical stellar mass ratio of 1:6.5. The FIR dust continuum emission traced by ALMA locates the bulk of star formation in extremely compact regions (median r e =0.70±0.29 kpc), and it is in all cases associated with the most massive component of the mergers (median M M log 10.49 0.32We compare spatially resolved UV slope (β) maps with the FIR dust continuum to study the infrared excess (IRX=L IR /L UV )-β relation. The SMGs display systematically higher IRX values than expected from the nominal trend, demonstrating that the FIR and UV emissions are spatially disconnected. Finally, we show that the SMGs fall on the mass-size plane at smaller stellar masses and sizes than the cQGs at z=2. Taking into account the expected evolution in stellar mass and size between z=4.5 and z=2 due to the ongoing starburst and mergers with minor companions, this is in agreement with a direct evolutionary connection between the two populations.