First survey of Wolf-Rayet star populations over the full extension of nearby galaxies observed with CALIFA

The search of extragalactic regions with conspicuous presence of Wolf-Rayet (WR) stars outside the Local Group is challenging task due to the difficulties in detecting their faint spectral features. In this exploratory work, we develop a methodology to perform an automated search of WR signatures through a pixel-by-pixel analysis of integral field spectroscopy (IFS) data belonging to the Calar Alto Legacy Integral Field Area survey, CALIFA. This technique allowed us to build the first catalogue of Wolf-Rayet rich regions with spatially-resolved information, allowing to study the properties of these complexes in a 2D context. The detection technique is based on the identification of the blue WR bump (around He II 4686 {\AA}, mainly associated to nitrogen-rich WR stars, WN) and the red WR bump (around C IV 5808 {\AA} and associated to carbon-rich WR stars, WC) using a pixel-by-pixel analysis. We identified 44 WR-rich regions with blue bumps distributed in 25 galaxies of a total of 558. The red WR bump was identified only in 5 of those regions. We found that the majority of the galaxies hosting WR populations in our sample are involved in some kind of interaction process. Half of the host galaxies share some properties with gamma-ray burst (GRB) hosts where WR stars, as potential candidates to being the progenitors of GRBs, are found. We also compared the WR properties derived from the CALIFA data with stellar population synthesis models, and confirm that simple star models are generally not able to reproduce the observations. We conclude that other effects, such as the binary star channel (which could extend the WR phase up to 10 Myr), fast rotation or other physical processes that causes the loss of observed Lyman continuum photons, are very likely affecting the derived WR properties, and hence should be considered when modelling the evolution of massive stars.Comment: 33 pages, accepted for publication in A&

Aperture effects on the oxygen abundance determinations from CALIFA data

This paper aims at providing aperture corrections for emission lines in a sample of spiral galaxies from the Calar Alto Legacy Integral Field Area Survey (CALIFA) database. In particular, we explore the behavior of the log([OIII]5007/Hbeta)/([NII]6583/Halpha) (O3N2) and log[NII]6583/Halpha (N2) flux ratios since they are closely connected to different empirical calibrations of the oxygen abundances in star forming galaxies. We compute median growth curves of Halpha, Halpha/Hbeta, O3N2 and N2 up to 2.5R_50 and 1.5 disk R_eff. The growth curves simulate the effect of observing galaxies through apertures of varying radii. The median growth curve of the Halpha/Hbeta ratio monotonically decreases from the center towards larger radii, showing for small apertures a maximum value of ~10% larger than the integrated one. The median growth curve of N2 shows a similar behavior, decreasing from the center towards larger radii. No strong dependence is seen with the inclination, morphological type and stellar mass for these growth curves. Finally, the median growth curve of O3N2 increases monotonically with radius. However, at small radii it shows systematically higher values for galaxies of earlier morphological types and for high stellar mass galaxies. Applying our aperture corrections to a sample of galaxies from the SDSS survey at 0.02<=z<=0.3 shows that the average difference between fiber-based and aperture corrected oxygen abundances, for different galaxy stellar mass and redshift ranges, reaches typically to ~11%, depending on the abundance calibration used. This average difference is found to be systematically biased, though still within the typical uncertainties of oxygen abundances derived from empirical calibrations. Caution must be exercised when using observations of galaxies for small radii (e.g. below 0.5R_eff) given the high dispersion shown around the median growth curves.Comment: Accepted for publication in Ap

Spatially Resolved Star Formation Main Sequence of Galaxies in the Califa Survey

The "main sequence of galaxies" - defined in terms of the total star formation rate ψ versus the total stellar mass M ∗ - is a well-studied tight relation that has been observed at several wavelengths and at different redshifts. All earlier studies have derived this relation from integrated properties of galaxies. We recover the same relation from an analysis of spatially resolved properties, with integral field spectroscopic (IFS) observations of 306 galaxies from the CALIFA survey. We consider the SFR surface density in units of log(M o yr-1 Kpc-2) and the stellar mass surface density in units of log(M o Kpc-2) in individual spaxels that probe spatial scales of 0.5-1.5 Kpc. This local relation exhibits a high degree of correlation with small scatter (σ = 0.23 dex), irrespective of the dominant ionization source of the host galaxy or its integrated stellar mass. We highlight (i) the integrated star formation main sequence formed by galaxies whose dominant ionization process is related to star formation, for which we find a slope of 0.81 ± 0.02; (ii) for the spatially resolved relation obtained with the spaxel analysis, we find a slope of 0.72 ± 0.04; and (iii) for the integrated main sequence, we also identified a sequence formed by galaxies that are dominated by an old stellar population, which we have called the retired galaxies sequence.Fil: Cano Díaz, M.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Sánchez, S. F.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Zibetti, S.. Osservatorio Astrofisico di Arcetri; Italia. Istituto Nazionale di Astrofisica; ItaliaFil: Ascasibar, Y.. Universidad Autónoma de Madrid; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Bland Hawthorn, J.. University of Sydney; AustraliaFil: Ziegler, B.. Universidad de Viena; AustriaFil: González Delgado, R. M.. Instituto de Astrofísica de Andalucía; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Walcher, C.J.. Gobierno de la República Federal de Alemania. Max Planck Institut für Astrophysik; AlemaniaFil: García Benito, Rubén. Instituto de Astrofísica de Andalucía; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Mast, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Mendoza Pérez, M. A.. Instituto de Astrofísica de Andalucía; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Falcón Barroso, J.. Instituto de Astrofísica de Canarias; España. Universidad de La Laguna; EspañaFil: Galbany, Lluís. Millennium Institute of Astrophysics; Chile. Universidad de Chile; ChileFil: Husemann, Bernd. European Southern Observator; AlemaniaFil: Kehrig, C.. Instituto de Astrofísica de Andalucía; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Marino, R. A.. Universidad Complutense de Madrid; España. ETH Zurich’s Institute for Astronomy; AlemaniaFil: Sánchez Blázquez, P.. Universidad Autónoma de Madrid; España. Pontificia Universidad Católica de Chile; ChileFil: López Cobá, C.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: López Sánchez, Á. R.. Australian Astronomical Observatory; Australia. Macquarie University; AustraliaFil: Vílchez, J. M.. Instituto de Astrofísica de Andalucía; España. Consejo Superior de Investigaciones Científicas; Españ

Aperture effects on the oxygen abundance determinations from Califa data

This paper aims to provide aperture corrections for emission lines in a sample of spiral galaxies from the Calar Alto Legacy Integral Field Area Survey (CALIFA) database. In particular, we explore the behavior of the log([O iii] λ5007/Hβ)/([N ii] λ6583/Hα) (O3N2) and log[N ii] λ6583/Hα (N2) flux ratios since they are closely connected to different empirical calibrations of the oxygen abundances in star-forming galaxies. We compute the median growth curves of Hα, Hα/Hβ, O3N2, and N2 up to 2.5R 50 and 1.5 disk . These distances cover most of the optical spatial extent of the CALIFA galaxies. The growth curves simulate the effect of observing galaxies through apertures of varying radii. We split these growth curves by morphological types and stellar masses to check if there is any dependence on these properties. The median growth curve of the Hα flux shows a monotonous increase with radius with no strong dependence on galaxy inclination, morphological type, and stellar mass. The median growth curve of the Hα/Hβ ratio monotonically decreases from the center toward larger radii, showing for small apertures a maximum value of ≈10% larger than the integrated one. It does not show any dependence on inclination, morphological type, and stellar mass. The median growth curve of N2 shows a similar behavior, decreasing from the center toward larger radii. No strong dependence is seen on the inclination, morphological type, and stellar mass. Finally, the median growth curve of O3N2 increases monotonically with radius, and it does not show dependence on the inclination. However, at small radii it shows systematically higher values for galaxies of earlier morphological types and for high stellar mass galaxies. Applying our aperture corrections to a sample of galaxies from the SDSS survey at 0.02 ≤ z ≤ 0.3 shows that the average difference between fiber-based and aperture-corrected oxygen abundances, for different galaxy stellar mass and redshift ranges, reaches typically to ≈11%, depending on the abundance calibration used. This average difference is found to be systematically biased, though still within the typical uncertainties of oxygen abundances derived from empirical calibrations. Caution must be exercised when using observations of galaxies for small radii (e.g., below 0.5 ) given the high dispersion shown around the median growth curves. Thus, the application of these median aperture corrections to derive abundances for individual galaxies is not recommended when their fluxes come from radii much smaller than either R 50 or Reff.Fil: Iglesias Páramo, J.. Instituto de Astrofísica de Andalucía; EspañaFil: Vílchez, J. M.. Instituto de Astrofísica de Andalucía; EspañaFil: Rosales Ortega, F. F.. Instituto Nacional de Astrofísica, Óptica y Electrónica; MéxicoFil: Sánchez, S. F.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Duarte Puertas, S.. Instituto de Astrofísica de Andalucía; EspañaFil: Petropoulou, V. Istituto Nazionale di Astrofisica; ItaliaFil: Gil de Paz, A.. Universidad Complutense de Madrid; EspañaFil: Galbany, L.. Millennium Institute Of Astrophysics; ChileFil: Mollá, M.. Universidad Complutense de Madrid; EspañaFil: Catalán Torrecilla, C.. Universidad Complutense de Madrid; EspañaFil: Castillo-Morales, A.. Universidad Complutense de Madrid; EspañaFil: Mast, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Husemann, Bernd. European Southern Observatory; AlemaniaFil: García Benito, Rubén. Instituto de Astrofísica de Andalucía; EspañaFil: Mendoza, M.. Instituto de Astrofísica de Andalucía; EspañaFil: Kehrig, C.. Instituto de Astrofísica de Andalucía; EspañaFil: Pérez Montero, E.. Instituto de Astrofísica de Andalucía; EspañaFil: The CALIFA collaboration. Centro Astronómico Hispano Alemán de Calar Alto; Españ

Neuroblastoma in Spain : Linking the national clinical database and epidemiological registries - A study by the Joint Action on Rare Cancers

Altres ajuts: Ministerio de Sanidad; Universitat de València; Sociedad Española de Oncología Pediátrica; Fundación de Oncología Infantil Enriqueta Villavecchia.Purpose: Linkage between clinical databases and population-based cancer registries may serve to evaluate European Reference Networks' (ERNs) activity, by monitoring the proportion of patients benefiting from these and their impact on survival at a population level. To test this, a study targeting neuroblastoma (Nb) was conducted in Spain by the European Joint Action on Rare Cancers. Material and methods: Subjects: Nb cases, incident 1999-2017, aged < 15 years. Linkage included: Spanish Neuroblastoma Clinical Database (NbCDB) (1217 cases); Spanish Registry of Childhood Tumours (RETI) (1514 cases); and 10 regional population-based registries (RPBCRs) which cover 33% of the childhood population (332 cases). Linkage was semiautomatic. We estimated completeness, incidence, contribution, deficit, and 5-year survival in the databases and specific subsets. Results: National completeness estimates for RETI and NbCDB were 91% and 72% respectively, using the Spanish RPBCRs on International Incidence of Childhood Cancer (https://iicc.iarc.fr/) as reference. RPBCRs' specific contribution was 1.6%. Linkage required manual crossover in 54% of the semiautomatic matches. Five-year survival was 74% (0-14 years) and 90% (0-18 months). Conclusions: All three databases were incomplete as regards Spain as a whole and should therefore be combined to achieve full childhood cancer registration. A unique personal patient identifier could facilitate such linkage. Most children have access to Nb clinical trials. Consolidated interconnections between the national registry and clinical registries (including ERNs and paediatric oncology clinical groups) should be established to evaluate outcomes