M. Pović

The evolution of the mass-size relation for early type galaxies from z 1 to the present: dependence on environment, mass-range and detailed morphology

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 early-type galaxies from the COSMOS survey, selected from z similar to 1 to the present, and with masses log(M/M-circle dot) \textgreater 10.5. From a detailed morphological analysis we infer that similar to 80 per cent of passive galaxies with mass log(M/M-circle dot) \textgreater 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-circle dot) \textgreater 11 - while S0 galaxies dominate at lower stellar masses -10.5 \textless log(M/M-circle dot) \textless 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 \textless log(M/M-circle dot) \textless 11 - ellipticals do not show strong size growth from z similar to 1 to the present (10 to 30 per cent depending on the morphological classification). On the other end, massive ellipticals -log(M/M-circle dot) \textgreater 11.2 - approximately doubled their size. Interestingly, lenticular galaxies display different behaviour: they appear more compact on average and they do show a size growth of similar to 60 per cent 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 modelling we cannot state clear evidence favouring 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-circle dot) \textless 14), i.e. group and field galaxies follow the same trends. At low redshift, where we examine both Sloan Digital Sky Survey 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-circle dot) \textgreater 11.2). In future work, we will analyse in detail if this result is specific of the observations and model used in this work. Brightest Cluster Galaxies (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.

The ALHAMBRA Survey: Bayesian photometric redshifts with 23 bands for 3 deg2

The ALHAMBRA (Advance Large Homogeneous Area Medium Band Re dshift Astronomical) survey has observed 8 different regions of the sky, incl uding sections of the COSMOS, DEEP2, ELAIS, GOODS-N, SDSS and Groth fields using a new photometric system with 20 contiguous �300 ˚ A filters covering the optical range, combining them with deep JHKs imaging. The observations, carried out with the Calar Alto 3.5m telescope using the wide field (0.25 deg 2 FOV) optical camera LAICA and the NIR instrument Omega-2000, correspond to �700hrs of on-target science images. The photometric system was specifically designed to maximize the effective depth of the survey in terms of accurate spectral-type and photometric redshift estimation along with the capability of identi fication of relatively faint emission lines. Here we present multicolor photometry and photometric redshifts for �438,000 galaxies, detected in synthetic F814W images, complete down to a magnitude I�24.5AB, carefully taking into account realistic noise estimates, and correct ing by PSF and aperture effects with the ColorPro software. The photometric zeropoints have been calibrated using stellar transformation equations and refined internally, using a new tech nique based on the highly robust photometric redshifts measured for emission line galaxies. We calculate photometric redshifts with the BPZ2.0 code, which includes new empirically calibrated galaxy templates and priors. —

Probing the nuclear and circumnuclear activity of NGC 1365 in the infrared

This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI/INAF (Italy) and CICYT/MCYT (Spain). SPIRE has been developed by a consortium of institutes led by Cardiff Univ. (UK) and including Univ. Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, Univ. Sussex (UK); and Caltech, JPL, NHSC, Univ. Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC, UKSA (UK); and NASA (USA).

The ALHAMBRA survey : evolution of galaxy clustering since z ~ 1.

PA-M was supported by an ERC StG Grant (DEGAS-259586). PN acknowledges the support of the Royal Society through the award of a University Research Fellowship and the European Research Council, through receipt of a Starting Grant (DEGAS-259586). This work was supported by the Science and Technology Facilities Council (grant number ST/F001166/1), by the Generalitat Valenciana (project of excellence Prometeo 2009/064), by the Junta de Andalucia (Excellence Project P08-TIC-3531) and by the SpanishMinistry for Science and Innovation (grantsAYA2010-22111-C03-01 and CSD2007-00060).

Resolving the nuclear dust distribution of the Seyfert 2 galaxy NGC 3081

CRA acknowledges financial support from STFC (ST/G001758/1) and from the Spanish Ministry of Science and Innovation (MICINN) through project Consolider-Ingenio 2010 Programme grant CSD2006-00070: First Science with the GTC. AMPG and JIGS acknowledge the Spanish Ministry of Science and Innovation (MICINN) through project AYA2008-06311-C02-01/02. AAR acknowledges the Spanish Ministry of Science and Innovation through projects AYA2010-18029 (Solar Magnetism and Astrophysical Spectropolarimetry). AAH and PE acknowledges support from the Spanish Plan Nacional de Astronomia y Astrofisica under grant AYA2009-05705-E. MP acknowledges Junta de Andalucia and Spanish Ministry of Science and Innovation through projects PO8-TIC-03531 and AYA2010-15169. PACS has been developed by a consortium of institutes led by MPE (Germany) and including UVIE (Austria); KU Leuven, CSL, IMEC (Belgium); CEA, LAM (France); MPIA (Germany); INAF-IFSI/OAA/OAP/OAT, LENS, SISSA (Italy); IAC (Spain). This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI/INAF (Italy) and CICYT/MCYT (Spain). SPIRE has been developed by a consortium of institutes led by Cardiff University (UK) and including University of Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, University of Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, University of Sussex (UK); and Caltech, JPL, NHSC, University of Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy);MCINN (Spain); SNSB (Sweden); STFC (UK) andNASA(USA).

Study of star-forming galaxies in SDSS up to redshift 0.4 I. Metallicity evolution

Context. The chemical composition of the gas in galaxies over cosmic time provides a very important tool for understanding galaxy evolution. Although there are many studies at high redshift, they are rather scarce at lower redshifts. However, low redshift studies can provide important clues about the evolution of galaxies, furnishing the required link between the local and high redshift universe. In this work, we focus on the metallicity of the gas of star-forming galaxies at low redshift, looking for signs of chemical evolution. Aims. We aim to analyze the metallicity contents star-forming galaxies of similar luminosities and masses at different redshifts. With this purpose, we present a study of the metallicity of relatively massive (log(Mstar/M� ) 10.5) star forming galaxies from SDSS–DR5 (Sloan Digital Sky Survey-data release 5), using different redshift intervals from 0.04 to 0.4. Methods. We used data processed with the STARLIGHT spectral synthesis code, correcting the fluxes for dust extinction, estimating metallicities using the R23 method, and segregating the samples with respect to the value of the [N ii] λ6583/[O ii] λ3727 line ratio in order to break the R23 degeneracy selecting the upper branch. We analyze the luminosity and mass-metallicity relations, and the effect of the Sloan fiber diameter looking for possible biases. Results. By dividing our redshift samples in intervals of similar magnitude and comparing them, significant signs of metallicity evolution are found. Metallicity correlates inversely with redshift: from redshift 0 to 0.4 a decrement of ∼0.1 dex in 12 + log(O/H) is found.

The ALHAMBRA survey: accurate merger fractions derived by PDF analysis of photometrically close pairs

Aims. Our goal is to develop and test a novel methodology to compute accurate close pair fractions with photometric redshifts. Methods. We improve the current methodologies to estimate the merger fraction fm from photometric redshifts by (i) using the full probability distribution functions (PDFs) of the sources in redshift space, (ii) including the variation in the luminosity of the sources with z in both the selection of the samples and in the luminosity ratio constrain, and (iii) splitting individual PDFs into red and blue spectral templates to deal robustly with colour selections. We test the performance of our new methodology with the PDFs provided by the ALHAMBRA photometric survey. Results. The merger fractions and rates from the ALHAMBRA survey are in excellent agreement with those from spectroscopic work, both for the general population and for red and blue galaxies. With the merger rate of bright (MB 20 1:1z) galaxies evolving as (1 + z) n , the power-law index n is larger for blue galaxies (n = 2:7 0:5) than for red galaxies (n = 1:3 0:4), confirming previous results. Integrating the merger rate over cosmic time, we find that the average number of mergers per galaxy since z = 1 is N red m = 0:57 0:05 for red galaxies and N blue m = 0:26 0:02 for blue galaxies. Conclusions. Our new methodology exploits statistically all the available information provided by photometric redshift codes and provides accurate measurements of the merger fraction by close pairs only using photometric redshifts. Current and future photometric surveys will benefit of this new methodology.

Galaxy clusters and groups in the ALHAMBRA survey

Ministerio de Economia y Competitividad AYA2010-22111-C03-02, AYA2010-15169, AYA2012-30789, AYA2013-48623-C2-2, AYA2013-42227-P, AYA2013-40611-P, AYA2011-29517-C03-01, AYA2014-58861-C3-1, AYA2010-15081

The ALHAMBRA survey: reliable morphological catalogue of 22 051 early- and late-type galaxies

This research was supported by the Junta de Andalucia through projects PO8-TIC-03531 and TIC114, the Spanish Ministry of Economy and Competitiveness (MINECO) through projects AYA2006-14046, AYA2010-15169, AYA2010-22111-C03-02, AYA2011-29517-C03-01, and the Generalitat Valenciana through project GV/Prometeo 2009/064. MP acknowledges financial support from JAE-Doc program of the Spanish National Research Council (CSIC), co-funded by the European Social Fund.

Star-forming galaxies in SDSS: signs of metallicity evolution

Context. Evolution of galaxies through cosmic time has been widely studied at high redshift, but there are a few studies in this field at lower redshifts. However, low-redshifts studies will provide important clues to the evolution of galaxies, furnishing the required link between local and high-redshift universe. Aims. In this work we focus on the metallicity of the gas in spiral galaxies at low redshift looking for signs of chemical evolution. We analyze the metallicity contents of star forming galaxies of similar luminosities at different redshifts, we studied the metallicity of star forming galaxies from SDSS-DR5 (Sloan Digital Sky Survey-Data Release 5), using different redshift intervals from 0.1 to 0.4. Methods. We used the public data of SDSS-DR5 processed with the STARLIGHT spectral synthesis code, correcting the fluxes for dust extinction, estimating metallicities using the R23 method, and analyzing the samples with respect to the [N ii] λ6583/[O ii] λ3727 line ratio. Results. From a final sample of 207 galaxies, we find a decrement in 12+log(O/H) corresponding to the redshift interval 0.3 < z < 0.4 of ∼0.1 dex with respect to the rest of the sample, which can be interpreted as evidence of the metallicity evolution in low-z galaxies.