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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

© ESO 2014. SFS thanks the director of CEFCA, M. Moles, for his sincere support. We thank the referee for his/her comments that have improved this manuscript. Based on observations made with ESO Telescopes at the Paranal Observatory under programme ID 60.A-9329. Support for L.G. and H.K. is provided by the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC12009, awarded to The Millennium Institute of Astrophysics, MAS. L.G. and H.K. acknowledge support by CONICYT through FONDECYT grants 3140566 and 3140563, respectively. S.F.S. acknowledges the Mexican National Council for Science and Technology (CONACYT) for financial support under the program Proyectos de Ciencia Básica. E.P. acknowledges funding from the Spanish MINECO grant AYA2010-15081. RA Marino was also funded by the Spanish programme of International Campus of Excellence Moncloa (CEI)., We present a study of the HII regions in the galaxy NGC 6754 from a two pointing mosaic comprising 197 637 individual spectra, using integral field spectroscopy recently acquired with the MUSE instrument during its Science Verification program. The data cover the entire galaxy out to similar to 2 effective radii (r(e)), sampling its morphological structures with unprecedented spatial resolution for a wide-field Integral Field Unit. A complete census of the HII regions limited by the atmospheric seeing conditions was derived, comprising 396 individual ionized sources. This is one of the largest and most complete catalogues of HII regions with spectroscopic information in a single galaxy. We use this catalogue to derive the radial abundance gradient in this SBb galaxy, finding a negative gradient with a slope consistent with the characteristic value for disk galaxies recently reported. The large number of HII regions allows us to estimate the typical mixing scale length (r(mix) similar to 0.4 r(e)), which sets strong constraints on the proposed mechanisms for metal mixing in disk galaxies, like radial movements associated with bars and spiral arms. We found evidence of an azimuthal variation in the oxygen abundance that may be connected with the radial migration. These results illustrate the unique capabilities of MUSE for the study of the enrichment mechanisms in Local Universe galaxies., Ministry of Economy, Development, and Tourism's Millennium Science Initiative, CONICYT through FONDECYT, Mexican National Council for Science and Technology (CONACYT), Spanish MINECO, Spanish programme of International Campus of Excellence Moncloa (CEI), ESO Telescopes at the Paranal Observatory, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© ESO 2014. We wish to thank Brad Gibson and Pierre Ocvirk for their constant advice. P.S.-B. acknowledges support from the Ramón y Cajal program, grant ATA2010-21322-C03-02 from the Spanish Ministry of Economy and Competitiveness (MINECO). F.F.R.O. acknowledges the Mexican National Council for Science and Technology (CONACYT) for financial support under the programme Estancias Posdoctorales y Sabáticas al Extranjero para la Consolidación de Grupos de Investigación, 2010-2012. We acknowledge financial support from the research projects under grants AYA2010-21887-C04-03, AYA2010-21322-C03-03 and AYA2010-15081 by the Spanish Ministerio de Ciencia e Innovación. J.F.-B. acknowledges support from the Ramón y Cajal Program, grants AYA2010-21322-C03-02 from the Spanish Ministry of Economy and Competitiveness (MINECO). R. A. M. is funded by the Spanish program of International Campues of Excellence Moncloa (CEI). C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. I.M. acknowledges financial support from the Junta de Andalucía through projects PO8-TIC-03531 and TIC114, and the Spanish Ministry of Economy and Competitiveness (MINECO) through the project AYA2010-15169. We acknowledge the usage of the HyperLeda database (http://leda.univ-lyon1.fr). Based on observations collected at the Centro Astronómico Hispano-Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut ur Astronomie and the Instituto de Astrofísica de Andalucía (CSIC). FCT/MCTES (Portugal) and POPH/FSE (EC). He acknowledges support by the Fundacao para a Ciencia e a Tecnologia (FCT) under project FCOMP-01-0124-FEDER-029170 (Reference FCT PTDC/FIS-AST/3214/2012), funded by FCT-MEC (PIDDAC) and FEDER (COMPETE). We also thanks the referee por his/her suggestions that have improved the final version of this paper., While studies of gasphase metallicity gradients in disc galaxies are common, very little has been done towards the acquisition of stellar abundance gradients in the same regions. We present here a comparative study of the stellar metallicity and age distributions in a sample of 62 nearly face-on, spiral galaxies with and without bars, using data from the CALIFA survey. We measure the slopes of the gradients and study their relation with other properties of the galaxies. We find that the mean stellar age and metallicity gradients in the disc are shallow and negative. Furthermore, when normalized to the effective radius of the disc, the slope of the stellar population gradients does not correlate with the mass or with the morphological type of the galaxies. In contrast to this, the values of both age and metallicity at similar to 2.5 scale lengths correlate with the central velocity dispersion in a similar manner to the central values of the bulges, although bulges show, on average, older ages and higher metallicities than the discs. One of the goals of the present paper is to test the theoretical prediction that non-linear coupling between the bar and the spiral arms is an efficient mechanism for producing radial migrations across significant distances within discs. The process of radial migration should flatten the stellar metallicity gradient with time and, therefore, we would expect flatter stellar metallicity gradients in barred galaxies. However, we do not find any difference in the metallicity or age gradients between galaxies with and without bars. We discuss possible scenarios that can lead to this lack of difference., Ramón y Cajal program from the Spanish Ministry of Economy and Competitiveness (MINECO), Mexican National Council for Science and Technology (CONACYT), Spanish Ministerio de Ciencia e Innovación, Spanish program of International Campus of Excellence Moncloa (CEI), Marie Curie Career Integration Grant, Junta de Andalucía, Spanish Ministry of Economy and Competitiveness (MINECO), Fundacao para a Ciencia e a Tecnologia (FCT), FCT-MEC (PIDDAC), FEDER (COMPETE), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© ESO, 2013. Artículo firmado por 33 autores. We would like to thank the anonymous referee for the review of our manuscript. The comments and suggestions helped to improve the content of the paper. R. A. Marino is funded by the Spanish program of International Campus of Excellence Moncloa (CEI). This study makes uses of the data provided by the Calar Alto Legacy Integral Field Area (CALIFA) survey (http://www.califa.caha.es). Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck-Institut fur Astronomie and the Instituto de Astrofísica de Andalucía (CSIC). 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 of 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. We thank the Viabilidad, Diseño, Acceso y Mejora funding program, ICTS-2009-10, for supporting the initial developement of this project. S.F.S., F.F.R.O., and D. Mast thank the Plan Nacional de Investigación y Desarrollo funding programs, AYA2012-31935 of the Spanish Ministerio de Economía y Competitividad, for the support given to this project. S. F. S thanks the the Ramón y Cajal project RyC-2011-07590 of the spanish Ministerio de Economía y Competitividad, for the support giving to this project. F. F. R. O. acknowledges the Mexican National Council for Science and Technology (CONACYT) for financial support under the program Estancias Postdoctorales y Sabáticas al Extranjero para la Consolidación de Grupos de Investigación, 2010-2012. We acknowledge financial support for the ESTALLIDOS collaboration by the Spanish Ministerio de Ciencia e Innovación under grant AYA2010-21887-C04-03. BG-L also acknowledges support from the Spanish Ministerio de Economía y Competitividad (MINECO) u, The use of integral field spectroscopy is since recently allowing to measure the emission line fluxes of an increasingly large number of star-forming galaxies, both locally and at high redshift. Many studies have used these fluxes to derive the gas-phase metallicity of the galaxies by applying the so-called strong-line methods. However, the metallicity indicators that these datasets use were empirically calibrated using few direct abundance data points (T_e-based measurements). Furthermore, a precise determination of the prediction intervals of these indicators is commonly lacking in these calibrations. Such limitations might lead to systematic errors in determining the gas-phase metallicity, especially at high redshift, which might have a strong impact on our understanding of the chemical evolution of the Universe. The main goal of this study is to review the most widely used empirical oxygen calibrations, O3N2 and N2, by using new direct abundance measurements. We pay special attention to (1) the expected uncertainty of these calibrations as a function of the index value or abundance derived and (2) the presence of possible systematic offsets. This is possible thanks to the analysis of the most ambitious compilation of T_e-based H II regions to date. This new dataset compiles the Te-based abundances of 603 H II regions extracted from the literature but also includes new measurements from the CALIFA survey. Besides providing new and improved empirical calibrations for the gas abundance, we also present a comparison between our revisited calibrations with a total of 3423 additional CALIFA H II complexes with abundances derived using the ONS calibration from the literature. The combined analysis of T_e-based and ONS abundances allows us to derive their most accurate calibration to date for both the O3N2 and N2 single-ratio indicators, in terms of all statistical significance, quality, and coverage of the parameters space. In particular, we infer that these indicators, Unión Europea. FP7, Ministerio de Economía y Competitividad (MINECO), Campus de Excelencia internacional (CEI) Moncloa, Subprograma de diseño, viabilidad, acceso y mejora de Instalaciones Científicas y Técnicas Singulares (ICTS) (MINECO), Proyecto Ramón y Cajal (MINECO), Consejo Nacional de Ciencia y Tecnología (CONACYT), México, ESTALLIDOS Collaboration (MICINN), Acciones marie Curie (EU), People´s Program, DAGAL network, Programa PNAYA, Fundacao para a Ciencia e a Tecnologia (FCT), Portugal, FCT-MEC (PIDDAC), Portugal, FONDOS FEDER (COMPETE), UE, Proyecto Estancias Postdoctorales y Sabáticas al Extranjero para la Consolidación de Grupos de Investigación (CONACYT), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© EDP Sciencies. Based on observations made with the Isaac Newton Telescope operated on the island of La Palma by the Royal Greenwich Observatory in the Spanish Observatorio del Roque de los Muchachos of the Instituto Astrofísica. This research has been support in part by the grant No. PB96-0645 from the Spanish Programa Sectorial de Promoción General del Conocimiento., UCM1612+1308 is a new emission-line galaxy identified in the context of the Universidad Complutense de Madrid (UCM) survey. This object was classified as Blue Compact Galaxy (BCG) from photometric data. A detailed spectroscopic study from new optical observations is presented now. The physical conditions and chemical composition are derived. The ionic abundances yield to a metallicity of 0.23±0.01Z_⊙ and a very low nitrogen to oxygen abundances ratio, log (N/O)= -1.74±0.07, supporting a primary nucleosynthesis origin for the nitrogen. The same value has been obtained for the sulfur to oxygen ratio. The comparison of the helium abundance with the oxygen and nitrogen abundances evidences a quickly enrichment of oxygen produced by massive stars. The ionizing cluster has been analyzed yielding a relatively low ionization parameter, log bar Ū=-3, total number of stars, log N^* = 6.18, stellar mass, log M^* = 5.71 M_⊙, and gas mass log M_g = 7.42M_⊙. A lower limit of the dust mass, log M_dust = 5.65M_⊙, has been obtained from the IRAS fluxes. The observed data and derived parameters, when interpreted with the evolutionary synthesis models by Leitherer & Heckman (1995), point out to an instantaneous burst with an age of log t= 6.7yr., Programa Sectorial de Promoción General del Conocimiento (MEC), España, Ministerio de Educación y Cultura (MEC), España, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© ESO 2014. We would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The support of the German BMBF and MPG, the Italian INFN, the Swiss National Fund SNF, and the Spanish MICINN is gratefully acknowledged. This work was also supported by the CPAN CSD2007-00042 and MultiDark CSD2009-00064 projects of the Spanish Consolider-Ingenio 2010 programme, by grant 127740 of the Academy of Finland, by the DFG Cluster of Excellence “Origin and Structure of the Universe”, by the Croatian Science Foundation Project 09/176, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, and by the Polish MNiSzW grant 745/N-HESSMAGIC/2010/0., Aims. HESS J1857+026 is an extended TeV gamma-ray source that was discovered by H. E. S. S. as part of its Galactic plane survey. Given its broadband spectral energy distribution and its spatial coincidence with the young energetic pulsar PSR J1856+0245, the source has been put forward as a pulsar wind nebula (PWN) candidate. MAGIC has performed follow-up observations aimed at mapping the source down to energies approaching 100 GeV in order to better understand its complex morphology. Methods. HESS J1857+026 was observed by MAGIC in 2010, yielding 29 h of good quality stereoscopic data that allowed us to map the source region in two separate ranges of energy. Results. We detected very-high-energy gamma-ray emission from HESS J1857+026 with a significance of 12 sigma above 150 GeV. The differential energy spectrum between 100 GeV and 13 TeV is described well by a power law function dN/dE = N-0(E/1TeV)(-Gamma) with N-0 = (5.37 +/- 0.44(stat) +/- 1.5(sys)) X 10(-12) (TeV-1 cm(-2) s(-1)) and Gamma = 2.16 +/- 0.07(stat) +/- 0.15(sys), which bridges the gap between the GeV emission measured by Fermi-LAT and the multi-TeV emission measured by H.E.S.S.. In addition, we present a detailed analysis of the energy-dependent morphology of this region. We couple these results with archival multiwavelength data and outline evidence in favor of a two-source scenario, whereby one source is associated with a PWN, while the other could be linked with a molecular cloud complex containing an HII region and a possible gas cavity., German BMBF, German MPG, Italian INFN, Swiss National Fund SNF, Spanish MICINN, Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

© ESO 2007. We thank the Spanish Plan Nacional de Astronomía program AYA2005-09413-C02-02, of the Spanish Ministery of Education and Science and the Plan Andaluz de Investigación of Junta de Andalucía as research group FQM322. M.V. thanks Matthias Steinmetz and the instrumentation group at the AIP for facilitating the construction of the PPak module and its integration into PMAS, the spectrograph used for this survey. We thank the referee, Prof. Dr. O’Dell, who helped us to improve the quality of this article with his valuable comments and suggestions, and his detailed check of the flux calibration., We present a low-resolution spectroscopic survey of the Orion nebula. The data are released for public use. We show the possible applications of this dataset analyzing some of the main properties of the nebula. Methods. We perform an integral field spectroscopy mosaic of an area of similar to 5' x 6' centered on the Trapezium region of the nebula, including the ionization front to the south-east. Analysis of the line fluxes and line ratios of both the individual and integrated spectra allowed us to determine the main characteristics of the ionization throughtout the nebula. Results. The final dataset comprises 8182 individual spectra, sampled in a circular area of similar to 2.7" diameter. The data can be downloaded as a single row-stacked spectra fit file plus a position table or as an interpolated datacube with a final sampling of 1.5"/pixel. The integrated spectrum across the field-of-view was used to obtain the main integrated properties of the nebula, including the electron density and temperature, the dust extinction, the Ha integrated flux (after correcting for dust reddening), and the main diagnostic line ratios. The individual spectra were used to obtain line intensity maps of the different detected lines. These maps were used to study the distribution of the ionized hydrogen, the dust extinction, the electron density and temperature, and the helium and oxygen abundance. All of them show a considerable degree of structure as already shown in previous studies. In particular, there is a tight relation between the helium and oxygen abundances and the ionization structure that cannot be explained by case B recombination theory. Simple arguments like partial ionization and dust mixed with the emitting gas may explain these relations. However a more detailed modeling is required, for which we provide the dataset., Spanish Plan Nacional de Astronomía program of the Spanish Ministery of Education and Science, Plan Andaluz de Investigación of Junta de Andalucía, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

© ESO 2022. Artículo firmado por 48 autores. This work was carried out as part of the PHANGS collaboration. E. S., F. S., R. M. E., T. G. W. acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 694343). S. C. O. G. and R. S. K. acknowledge financial support from the German Research Foundation (DFG) via the collaborative research centre (SFB 881, Project-ID 138713538) "The Milky Way System" (subprojects A1, B1, B2, and B8). They also acknowledge funding from the Heidelberg Cluster of Excellence "STRUCTURES" in the framework of Germany's Excellence Strategy (grant EXC-2181/1, Project-ID 390900948) and from the European Research Council via the ERC Synergy Grant "ECOGAL" (grant 855130). F. Bi, A. T. B., I. B. acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 726384/Empire). C. E. acknowledges funding from the Deutsche Forschungsgemeinschaft (DFG) Sachbeihilfe, grant number BI1546/3-1. E. J. W. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Project-ID 138713538 - SFB 881 ("The Milky Way System", subproject P2). J. M. D. K. and M. C. gratefully acknowledge funding from the Deutsche Forschungsgemeinschaft (DFG) through an Emmy Noether Research Group (grant number KR4801/1-1) and the DFG Sachbeihilfe (grant number KR4801/2-1) and from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme via the ERC Starting Grant MUSTANG (grant agreement number 714907). E. C. acknowledges support from ANID project Basal AFB-170002. K. K., O. E., and F. S. gratefully acknowledge funding from the German Research Foundation (DFG) in the form of an Emmy Noether Research Group (grant number KR4598/2-1, PI: Kreckel). E. W. acknowledges support from the DFG via SFB 881 "The Milky Way S, We present the PHANGS-MUSE survey, a programme that uses the MUSE integral field spectrograph at the ESO VLT to map 19 massive (9.4< log(M/M-circle dot)< 11.0) nearby (D less than or similar to 20 Mpc) star-forming disc galaxies. The survey consists of 168 MUSE pointings (1 ' by 1 ' each) and a total of nearly 15 x 10(6) spectra, covering similar to 1.5 x 10(6) independent spectra. PHANGS-MUSE provides the first integral field spectrograph view of star formation across different local environments (including galaxy centres, bars, and spiral arms) in external galaxies at a median resolution of 50 pc, better than the mean inter-cloud distance in the ionised interstellar medium. This 'cloud-scale' resolution allows detailed demographics and characterisations of H II regions and other ionised nebulae. PHANGS-MUSE further delivers a unique view on the associated gas and stellar kinematics and provides constraints on the star-formation history. The PHANGS-MUSE survey is complemented by dedicated ALMA CO(2-1) and multi-band HST observations, therefore allowing us to probe the key stages of the star-formation process from molecular clouds to H II regions and star clusters. This paper describes the scientific motivation, sample selection, observational strategy, data reduction, and analysis process of the PHANGS-MUSE survey. We present our bespoke automated data-reduction framework, which is built on the reduction recipes provided by ESO but additionally allows for mosaicking and homogenisation of the point spread function. We further present a detailed quality assessment and a brief illustration of the potential scientific applications of the large set of PHANGS-MUSE data products generated by our data analysis framework. The data cubes and analysis data products described in this paper represent the basis for the first PHANGS-MUSE public data release and are available in the ESO archive and via the Canadian Astronomy Data Centre., Unión Europea. Horizonte 2020, German Research Foundation (DFG) via the collaborative research centre, Heidelberg Cluster of Excellence "STRUCTURES" of Germany's Excellence Strategy, Deutsche Forschungsgemeinschaft (DFG) Sachbeihilfe German Research Foundation (DFG), Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Deutsche Forschungsgemeinschaft (DFG) through an Emmy Noether Research Group German Research Foundation (DFG), DFG Sachbeihilfe German Research Foundation (DFG), German Research Foundation (DFG) in the form of an Emmy Noether Research Group, ANID project Basal, DFG German Research Foundation (DFG) European Commission, Programme National "Physique et Chimie du Milieu Interstellaire" (PCMI) of CNRS/INSU, INC/INP, CEA French Atomic Energy Commission, CNES Centre National D'etudes Spatiales, European Southern Observatory under ESO programmes, Space Telescope Science Institute under NASA Space Telescope Science Institute, NASA National Aeronautics & Space Administration (NASA), Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub