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© ESO 2016. Artículo firmado por 22 autores. This study makes uses of the data provided by the Calar Alto Legacy Integral Field Area (CALIFA) survey (http://califa.caha.es/). CALIFA is the first legacy survey being performed at Calar Alto. The CALIFA collaboration would like to thank the IAA-CSIC and MPIA-MPG as major partners at the observatory, and CAHA itself, for the unique access to telescope time and support in manpower and infrastructures. The CALIFA collaboration also thanks the CAHA staff for their dedication to this project. E.P.M., J.M.V., C.K., S.P., and J.I.P. acknowledge support from the Spanish MICINN through grants AYA2010-21887-C04-01 and AYA2013-47742-C4-1-P and the Junta de Andalucía for grant EXC/2011 FQM-7058. R.G.B., R.G.D., and E.P. acknowledge support from grants AYA2014-57490-P and JA-FQM-2828. Support for L.G. is provided by the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009, awarded to The Millennium Institute of Astrophysics, MAS. L.G. acknowledges support by CONICYT through FONDECYT grant 3140566. This research made use of python (http://www.python.org), of Matplotlib (Hunter 2007), a suite of open-source python modules that provides a framework for creating scientific plots. We also thank Dr. Christophe Morisset for many discussions and constructive comments that have helped to improve the original manuscript., Context. The study of the integrated properties of star-forming galaxies is central to understand their formation and evolution. Some of these properties are extensive and therefore their analysis require totally covering and spatially resolved observations. Among these properties, metallicity can be defined in spiral discs by means of integral field spectroscopy (IFS) of individual H II regions. The simultaneous analysis of the abundances of primary elements, as oxygen, and secondary, as nitrogen, also provides clues about the star formation history and the processes that shape the build-up of spiral discs. Aims. Our main aim is to analyse simultaneously O/H and N/O abundance ratios in H II regions in different radial positions of the discs in a large sample of spiral galaxies to obtain the slopes and the characteristic abundance ratios that can be related to their integrated properties. Methods. We analysed the optical spectra of individual selected H II regions extracted from a sample of 350 spiral galaxies of the CALIFA survey. We calculated total O/H abundances and, for the first time, N/O ratios using the semi-empirical routine H II-C HI-MISTRY, which, according to Perez-Montero (2014, MNRAS, 441, 2663), is consistent with the direct method and reduces the uncertainty in the O/H derivation using [N II] lines owing to the dispersion in the O/H-N/O relation. Then we performed linear fittings to the abundances as a function of the de-projected galactocentric distances. Results. The analysis of the radial distribution both for O/H and N/O in the non-interacting galaxies reveals that both average slopes are negative, but a non-negligible fraction of objects have a flat or even a positive gradient (at least 10% for O/H and 4% for N/O). The slopes normalised to the effective radius appear to have a slight dependence on the total stellar mass and the morphological type, as late low-mass objects tend to have flatter slopes. No clear relation is found, however, to expla, Ministerio de Ciencia e Innovación (MICINN), Junta de Andalucía, Millennium Science Initiative (MSI) - Ministerio de Economía, Fomento y Turismo (Chile), Comisión Nacional de Investigación Científica y Tecnológica (CONICYT), Chile), Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT), Chile, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

This article has been accepted for publication in Monthly notices of the Royal Astronomical Society Journal © 2013 RAS. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. AH-C and AA-H acknowledge funding by the Universidad de Cantabria Augusto González Linares program. We acknowledge support from the Spanish Programa Nacional de Astronomía y Astrofísica under grants AYA2009-07723-E and AYA2009-10368. SHARDS has been funded by the Spanish MICINN/MINECO under the Consolider-Ingenio 2010 Program grant CSD2006-00070: First Science with the GTC. This work has made use of the Rainbow Cosmological Surveys Database, which is operated by the Universidad Complutense de Madrid (UCM). Based on observations made with the GTC, installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, in the island of La Palma. We thank all the GTC Staff for their support and enthusiasm with the SHARDS project, and we would like to especially acknowledge the help from Antonio Cabrera and Rene Rutten. We also thank the anonymous referee for their useful comments that helped to improve this paper., We report on results from the analysis of a stellar mass-selected (log (M-*/M-circle dot) >= 9.0) sample of 1644 galaxies at 0.65 < z < 1.1 with ultradeep (m(AB) < 26.5) optical medium-band (R similar to 50) photometry from the Survey for High-z Absorption Red and Dead Sources (SHARDS). The spectral resolution of SHARDS allows us to consistently measure the strength of the 4000 A spectral break [D-n(4000), an excellent age indicator for the stellar populations of quiescent galaxies] for all galaxies at z similar to 0.9 down to log (M-*/M-circle dot) similar to 9. The D-n(4000) index cannot be resolved from broad-band photometry, and measurements from optical spectroscopic surveys are typically limited to galaxies at least 10 times more massive. When combined with the rest-frame U - V colour, (U - V)(r), D-n(4000) provides a powerful diagnostic of the extinction affecting the stellar population that is relatively insensitive to degeneracies with age, metallicity or star formation history. We use this novel approach to estimate de-reddened colours and light-weighted stellar ages for individual sources. We explore the relationships linking stellar mass, (U - V)(r), and D-n(4000) for the sources in the sample, and compare them to those found in local galaxies. The main results are: (a) both D-n(4000) and (U - V)(r) correlate with M-*. The dispersion in D-n(4000) values at a given M-* increases with M-*, while the dispersion for (U - V)(r) decreases due to the higher average extinction prevalent in massive star-forming galaxies. (b) For massive galaxies, we find a smooth transition between the blue cloud and red sequence in the intrinsic U - V colour, in contrast with other recent results. (c) At a fixed stellar age, we find a positive correlation between extinction and stellar mass. (d) The fraction of sources with declining or halted star formation increases steeply with the stellar mass, from similar to 5 per cent at log (M-*/M-circle dot) = 9.0-9.5 to similar to 80 p, Universidad de Cantabria Augusto Gonzalez Linares program, Spanish Programa Nacional de Astronomia y Astrofisica, Spanish MICINN/MINECO under the Consolider-Ingenio Program, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

Studying galaxies at different cosmic epochs entails several observational effects that need to be taken into account to compare populations across a large time-span in a consistent manner. We use a sample of 166 nearby galaxies that hosted type Ia supernovae (SNe Ia) and have been observed with the integral field spectrograph MUSE as part of the AMUSING survey. Here, we present a study of the systematic errors and bias on the host stellar mass with increasing redshift, which are generally overlooked in SNe Ia cosmological analyses. We simulate observations at different redshifts (0.1 < z < 2.0) using four photometric bands (griz, similar to the Dark Energy Survey-SN program) to then estimate the host galaxy properties across cosmic time. We find that stellar masses are systematically underestimated as we move towards higher redshifts, due mostly to different rest-frame wavelength coverage, with differences reaching 0.3 dex at z similar to 1. We used the newly derived corrections as a function of redshift to correct the stellar masses of a known sample of SN Ia hosts and derive cosmological parameters. We show that these corrections have a small impact on the derived cosmological parameters. The most affected is the value of the mass step Delta(M), which is reduced by similar to 0.004 (6% lower). The dark energy equation of state parameter w changes by Delta w similar to 0.006 (0.6% higher) and the value of Omega(m) increases at most by 0.001 (similar to 0.3%), all within the derived uncertainties of the model. While the systematic error found in the estimate of the host stellar mass does not significantly affect the derived cosmological parameters, it is an important source of systematic error that needs to be corrected for as we enter a new era of precision cosmology.

Studying galaxies at different cosmic epochs entails several observational effects that need to be taken into account to compare populations across a large time-span in a consistent manner. We use a sample of 166 nearby galaxies that hosted type Ia supernovae (SNe Ia) and have been observed with the integral field spectrograph MUSE as part of the AMUSING survey. Here, we present a study of the systematic errors and bias on the host stellar mass with increasing redshift, which are generally overlooked in SNe Ia cosmological analyses. We simulate observations at different redshifts (0.1 < z < 2.0) using four photometric bands (griz, similar to the Dark Energy Survey-SN program) to then estimate the host galaxy properties across cosmic time. We find that stellar masses are systematically underestimated as we move towards higher redshifts, due mostly to different rest-frame wavelength coverage, with differences reaching 0.3 dex at z similar to 1. We used the newly derived corrections as a function of redshift to correct the stellar masses of a known sample of SN Ia hosts and derive cosmological parameters. We show that these corrections have a small impact on the derived cosmological parameters. The most affected is the value of the mass step Delta(M), which is reduced by similar to 0.004 (6% lower). The dark energy equation of state parameter w changes by Delta w similar to 0.006 (0.6% higher) and the value of Omega(m) increases at most by 0.001 (similar to 0.3%), all within the derived uncertainties of the model. While the systematic error found in the estimate of the host stellar mass does not significantly affect the derived cosmological parameters, it is an important source of systematic error that needs to be corrected for as we enter a new era of precision cosmology.

We report on the stellar content, half-light radii and star formation rates of a sample of 10 known high-redshift (z greater than or similar to 2) galaxies selected on strong neutral hydrogen (Hi) absorption () towards background quasars. We use observations from the Hubble Space Telescope Wide Field Camera 3 in three broad-band filters to study the spectral energy distribution (SED) of the galaxies. Using careful quasar point spread function subtraction, we study their galactic environments, and perform the first systematic morphological characterization of such absorption-selected galaxies at high redshifts. Our analysis reveals complex, irregular hosts with multiple star-forming clumps. At a spatial sampling of 0.067 arcsec per pixel (corresponding to 0.55 kpc at the median redshift of our sample), 40 percent of our sample requires multiple Sersic components for an accurate modelling of the observed light distributions. Placed on the mass-size relation and the 'main sequence' of star-forming galaxies, we find that absorption-selected galaxies at high redshift extend known relations determined from deep luminosity-selected surveys to an order of magnitude lower stellar mass, with objects primarily composed of star-forming, late-type galaxies. We measure half-light radii in the range r(1/2) similar to 0.4 to 2.6 kpc based on the reddest band (F160W) to trace the oldest stellar populations, and stellar masses in the range log(M-star/M-circle dot) similar to 8 to 10 derived from fits to the broad-band SED. Spectroscopic and SED-based star formation rates are broadly consistent, and lie in the range to 1.7.

We study the star formation rate (SFR), stellar mass (M-*), and the gas metallicity (Z) for 4636 galaxy pairs using the Galaxy And Mass Assembly (GAMA) survey. Our galaxy pairs lie in a redshift range of 0 250 km s(-1)) and high multiplicity.

We report on the stellar content, half-light radii and star formation rates of a sample of 10 known high-redshift (z greater than or similar to 2) galaxies selected on strong neutral hydrogen (Hi) absorption () towards background quasars. We use observations from the Hubble Space Telescope Wide Field Camera 3 in three broad-band filters to study the spectral energy distribution (SED) of the galaxies. Using careful quasar point spread function subtraction, we study their galactic environments, and perform the first systematic morphological characterization of such absorption-selected galaxies at high redshifts. Our analysis reveals complex, irregular hosts with multiple star-forming clumps. At a spatial sampling of 0.067 arcsec per pixel (corresponding to 0.55 kpc at the median redshift of our sample), 40 percent of our sample requires multiple Sersic components for an accurate modelling of the observed light distributions. Placed on the mass-size relation and the 'main sequence' of star-forming galaxies, we find that absorption-selected galaxies at high redshift extend known relations determined from deep luminosity-selected surveys to an order of magnitude lower stellar mass, with objects primarily composed of star-forming, late-type galaxies. We measure half-light radii in the range r(1/2) similar to 0.4 to 2.6 kpc based on the reddest band (F160W) to trace the oldest stellar populations, and stellar masses in the range log(M-star/M-circle dot) similar to 8 to 10 derived from fits to the broad-band SED. Spectroscopic and SED-based star formation rates are broadly consistent, and lie in the range to 1.7.

We study the star formation rate (SFR), stellar mass (M-*), and the gas metallicity (Z) for 4636 galaxy pairs using the Galaxy And Mass Assembly (GAMA) survey. Our galaxy pairs lie in a redshift range of 0 250 km s(-1)) and high multiplicity.

We have used the Atacama Large Millimeter/submillimeter Array (ALMA) to carry out a search for CO (3-2) or (4-3) emission from the fields of 12 high-metallicity ([M/H]...-0.72 dex) damped Lya absorbers (DLAs) at z approximate to 1.7-2.6. We detected CO emission from galaxies in the fields of five DLAs (two of which have been reported earlier), obtaining high molecular gas masses, M-mol approximate to (1.3-20.7) x (alpha C-O/4.36) x 10(10) M-circle dot. The impact parameters of the CO emitters to the QSO sight line lie in the range b similar to 5.6-100 kpc, with the three new CO detections having b less than or similar to 15 kpc. The highest CO line luminosities and inferred molecular gas masses are associated with the highest-metallicity DLAs, with [M/H] greater than or similar to -0.3 dex. The high inferred molecular gas masses may be explained by a combination of a stellar mass-metallicity relation and a high molecular gas-to-star mass ratio in high-redshift galaxies; the DLA galaxies identified by our CO searches have properties consistent with those of emission-selected samples. None of the DLA galaxies detected in CO emission were identified in earlier optical or near-IR searches and vice versa; DLA galaxies earlier identified in optical/near-IR searches were not detected in CO emission. The high ALMA CO and C[II] 158 mu m detection rate in high-z, high-metallicity DLA galaxies has revolutionized the field, allowing the identification of dusty, massive galaxies associated with high-z DLAs. The H I-absorption criterion identifying DLAs selects the entire high-z galaxy population, including dusty and UVbright galaxies, in a wide range of environments.

The amount of cold, molecular gas in high-redshift galaxies is typically inferred from proxies of molecular hydrogen (H-2), such as carbon monoxide (CO) or neutral atomic carbon ([C i]) and molecular gas mass conversion factors. The use of these proxies, however, relies on modeling and observations that have not been directly measured outside the local universe. Here, we use recent samples of high-redshift gamma-ray burst (GRB) and quasar molecular gas absorbers to determine this conversion factor from the column density of H-2, which gives us the mass per unit column, and the [C i](J = 1) column density, which provides the luminosity per unit column. This technique allows us to make direct measurements of the relative abundances in high-redshift absorption-selected galaxies. Our sample spans redshifts of z = 1.9-3.4 and covers two orders of magnitude in gas-phase metallicity. We find that the [C i]-to-M-mol conversion factor is metallicity dependent, with alpha([C i]) scaling linearly with the metallicity: with a scatter of sigma alpha([CI]) = 0.2 dex. Using a sample of emission-selected galaxies at z similar to 0-5, with both [C i] and CO line detections, we apply the alpha([C i]) conversion to derive independent estimates of the molecular gas mass and the CO-to-M-mol, alpha(CO), conversion factor. We find a remarkable agreement between the molecular gas masses inferred from the absorption-derived alpha([C i]) compared to typical alpha(CO)-based estimates, which we confirm here to be metallicity-dependent as well, with an inferred slope that is consistent with alpha(CI) and previous estimates from the literature. These results thus support the use of the absorption-derived alpha([C i]) conversion factor for emission-selected star-forming galaxies and demonstrate that both methods probe the same universal properties of molecular gas in the local and high-redshift universe.

The amount of cold, molecular gas in high-redshift galaxies is typically inferred from proxies of molecular hydrogen (H-2), such as carbon monoxide (CO) or neutral atomic carbon ([C i]) and molecular gas mass conversion factors. The use of these proxies, however, relies on modeling and observations that have not been directly measured outside the local universe. Here, we use recent samples of high-redshift gamma-ray burst (GRB) and quasar molecular gas absorbers to determine this conversion factor from the column density of H-2, which gives us the mass per unit column, and the [C i](J = 1) column density, which provides the luminosity per unit column. This technique allows us to make direct measurements of the relative abundances in high-redshift absorption-selected galaxies. Our sample spans redshifts of z = 1.9-3.4 and covers two orders of magnitude in gas-phase metallicity. We find that the [C i]-to-M-mol conversion factor is metallicity dependent, with alpha([C i]) scaling linearly with the metallicity: with a scatter of sigma alpha([CI]) = 0.2 dex. Using a sample of emission-selected galaxies at z similar to 0-5, with both [C i] and CO line detections, we apply the alpha([C i]) conversion to derive independent estimates of the molecular gas mass and the CO-to-M-mol, alpha(CO), conversion factor. We find a remarkable agreement between the molecular gas masses inferred from the absorption-derived alpha([C i]) compared to typical alpha(CO)-based estimates, which we confirm here to be metallicity-dependent as well, with an inferred slope that is consistent with alpha(CI) and previous estimates from the literature. These results thus support the use of the absorption-derived alpha([C i]) conversion factor for emission-selected star-forming galaxies and demonstrate that both methods probe the same universal properties of molecular gas in the local and high-redshift universe.