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The CALIFA survey across the Hubble sequence: Spatially resolved stellar population properties in galaxies
Biblos-e Archivo. Repositorio Institucional de la UAM
- González Delgado, R. M.
- García-Benito, R.
- Pérez, E.
- Cid Fernandes, R.
- De Amorim, A. L.
- Cortijo-Ferrero, C.
- López Fernández, Rafael
- Vale-Asari, N.
- Sánchez, S. F.
- Mollá, M.
- Ruiz-Lara, T.
- Sánchez-Blázquez, Patricia
- Walcher, C. J.
- Alves, J.
- Aguerri, J. Alfonso L
- Bekeraité, S.
- Bland-Hawthorn, J.
- Galbany, L.
- Gallazzi, A.
- Husemann, B.
- Iglesias-Páramo, J.
- Kalinova, V.
- López-Sánchez, A. R.
- Marino, R. A.
- Márquez, I.
- Masegosa, J.
- Mast, D.
- Méndez-Abreu, Jairo
- Mendoza, A.
- Del Olmo, A.
- Pérez, I.
- Quirrenbach, A.
- Zibetti, S.
- Califa Collaboration
- Lacerda, E. A. D.
Astronomy and Astrophysics 581 (2015): A103 reproduced with permission from Astronomy & Astrophysics, © ESO, Various different physical processes contribute to the star formation and stellar mass assembly histories of galaxies. One important approach to understanding the significance of these different processes on galaxy evolution is the study of the stellar population content of today's galaxies in a spatially resolved manner. The aim of this paper is to characterize in detail the radial structure of stellar population properties of galaxies in the nearby universe, based on a uniquely large galaxy sample, considering the quality and coverage of the data. The sample under study was drawn from the CALIFA survey and contains 300 galaxies observed with integral field spectroscopy. These cover a wide range of Hubble types, from spheroids to spiral galaxies, while stellar masses range from M ͙ ∼ 109 to 7 × 1011 M⊙. We apply the fossil record method based on spectral synthesis techniques to recover the following physical properties for each spatial resolution element in our target galaxies: the stellar mass surface density (μ ͙), stellar extinction (AV), light-weighted and mass-weighted ages (˂log age˃L, ˂log age˃M), and mass-weighted metallicity (˂log Z˃M). To study mean trends with overall galaxy properties, the individual radial profiles are stacked in seven bins of galaxy morphology (E, S0, Sa, Sb, Sbc, Sc, and Sd). We confirm that more massive galaxies are more compact, older, more metal rich, and less reddened by dust. Additionally, we find that these trends are preserved spatially with the radial distance to the nucleus. Deviations from these relations appear correlated with Hubble type: earlier types are more compact, older, and more metal rich for a given M, which is evidence that quenching is related to morphology, but not driven by mass. Negative gradients of ˂log age˃L are consistent with an inside-out growth of galaxies, with the largest ˂log age˃ L gradients in Sb-Sbc galaxies. Further, the mean stellar ages of disks and bulges are correlated and with disks covering a wider range of ages, and late-type spirals hosting younger disks. However, age gradients are only mildly negative or flat beyond R ∼ 2 HLR (half light radius), indicating that star formation is more uniformly distributed or that stellar migration is important at these distances. The gradients in stellar mass surface density depend mostly on stellar mass, in the sense that more massive galaxies are more centrally concentrated. Whatever sets the concentration indices of galaxies obviously depends less on quenching/morphology than on the depth of the potential well. There is a secondary correlation in the sense that at the same M early-type galaxies have steeper gradients. The μ gradients outside 1 HLR show no dependence on Hubble type. We find mildly negative ˂log Z˃M gradients, which are shallower than predicted from models of galaxy evolution in isolation. In general, metallicity gradients depend on stellar mass, and less on morphology, hinting that metallicity is affected by both - the depth of the potential well and morphology/quenching. Thus, the largest ˂log Z˃M gradients occur in Milky Way-like Sb-Sbc galaxies, and are similar to those measured above the Galactic disk. Sc spirals show flatter ˂log Z˃M gradients, possibly indicating a larger contribution from secular evolution in disks. The galaxies from the sample have decreasing-outward stellar extinction; all spirals show similar radial profiles, independent from the stellar mass, but redder than E and S0. Overall, we conclude that quenching processes act in manners that are independent of mass, while metallicity and galaxy structure are influenced by mass-dependent processes, Support from the Spanish Ministerio de Economía y Competitividad, through projects AYA2010-15081 (PI R.G.D.), and Junta de Andalucía FQ1580 (PI R.G.D.), AYA2010-22111-C03-03, and AYA2010-10904E (S.F.S.). We also thank the Viabilidad, Diseño, Acceso y Mejora funding program, ICTS-2009-10, for funding the data acquisition of this project. R.C.F. thanks the hospitality of the IAA and the support of CAPES and CNPq. R.G.D. acknowledges the support of CNPq (Brazil) through Programa Ciencia sem Fronteiras (401452/2012-3). A.G. acknowledges support from EU FP7/2007-2013 under grant agreement n.267251 (AstroFIt) and from the EU Marie Curie Integration Grant “SteMaGE” Nr. PCIG12-GA-2012-326466. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. E.P. acknowledges support from the Guillermo Haro program at INAOE. 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. J.I.P. acknowledges financial support from the Spanish MINECO under grant AYA2010-21887- C04-01 and from Junta de Andalucía Excellence Project PEX2011-FQM7058. I.M., J.M. and A.d.O. acknowledge support from the project AYA2013-42227-P. RAM is funded by the Spanish program of International Campus of Excellence Moncloa (CEI). J.M.A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild)
IMF-Metallicity: A tigh local relation revealed by the CALIFA survey
Biblos-e Archivo. Repositorio Institucional de la UAM
- Martín-Navarro, I.
- Vazdekis, A.
- La Barbera, F.
- Falcón-Barroso, J.
- Lyubenova, M.
- Ferreras, I.
- Sánchez, S. F.
- Trager, S. C.
- García-Benito, R.
- Mast, D.
- Mendoza, M. A.
- Sánchez-Blázquez, Patricia
- González Delgado, R.
- Walcher, C. J.
- The CALIFA Team
- Van de Ven, Glenn
Astrophysical Journal Letters 806.2 (2015): L31 reproduced by permission of the AAS, Variations in the stellar initial mass function (IMF) have been invoked to explain the spectroscopic and dynamical properties of early-type galaxies (ETGs). However, no observations have yet been able to disentangle the physical driver. We analyze here a sample of 24 ETGs drawn from the CALIFA survey, deriving in a homogeneous way their stellar population and kinematic properties. We find that the local IMF is tightly related to the local metallicity, becoming more bottom-heavy toward metal-rich populations. Our result, combined with the galaxy mass-metallicity relation, naturally explains previous claims of a galaxy mass-IMF relation, derived from non-IFU spectra. If we assume that - within the star formation environment of ETGs - metallicity is the main driver of IMF variations, a significant revision of the interpretation of galaxy evolution observables is necessary, We acknowledge support from grants AYA2013-48226-C3-1 P and AYA2010-15081 from the Spanish MINECO. C.J.W. acknowledges support through the Marie Curie Career
Integration Grant 303912. P.S.-B. acknowledges support from the Ramón y Cajal program, ATA2010-21322-C03-02 (MINECO). J.F.B. and Gvd.V. acknowledge the DAGAL
network from the People Programme (Marie Curie Actions) of the European Unions Seventh Framework Programme FP7/2007–2013 under REA grant agreement number PITN-GA-2011-289313
Integration Grant 303912. P.S.-B. acknowledges support from the Ramón y Cajal program, ATA2010-21322-C03-02 (MINECO). J.F.B. and Gvd.V. acknowledge the DAGAL
network from the People Programme (Marie Curie Actions) of the European Unions Seventh Framework Programme FP7/2007–2013 under REA grant agreement number PITN-GA-2011-289313
Proyecto: EC, EC/FP7, FP7/289313, 303912
Outer-disk reddening and gas-phase metallicities: The CALIFA connection
Biblos-e Archivo. Repositorio Institucional de la UAM
- Sánchez-Blázquez, Patricia
- Marino, R. A.
- Gil De Paz, A.
- Sánchez, S. F.
- Sánchez-Blázquez, Patricia
- Cardiel, N.
- Castillo- Morales, A.
- Pascual, S.
- Vílchez, J.
- Kehrig, C.
- Mollá, M.
- Méndez-Abreu, Jairo
- Catalán-Torrecilla, C.
- Florido, E.
- Perez, I.
- Ruiz-Lara, T.
- Ellis, S.
- López-Sánchez, A. R.
- González Delgado, R.M
- De Lorenzo-Cáceres, A.
- García-Benito, R.
- Galbany, L.
- Cortijo, C.
- Kalinova, V.
- Mast, D.
- Iglesias-Páramo, J.
- Papaderos, P.
- Walcher, C.J.
- Bland-Hawthorn, J.
- Zibetti, S.
- CALIFA Team
Astronomy and Astrophysics 585 (2016): A47 reproduced with permission from Astronomy & Astrophysics, We study, for the first time in a statistically significant and well-defined sample, the relation between the outer-disk ionized-gas metallicity gradients and the presence of breaks in the surface brightness profiles of disk galaxies. Sloan Digital Sky Survey (SDSS) g′- and r′-band surface brightness, (g′ - r′) color, and ionized-gas oxygen abundance profiles for 324 galaxies within the Calar Alto Legacy Integral Field Area (CALIFA) survey are used for this purpose. We perform a detailed light-profile classification, finding that 84% of our disks show down- or up-bending profiles (Type II and Type III, respectively), while the remaining 16% are well fitted by one single exponential (Type I). The analysis of the color gradients at both sides of this break shows a U-shaped profile for most Type II galaxies with an average minimum (g′ - r′) color of ∼ 0.5mag and an ionized-gas metallicity flattening associated with it only in the case of low-mass galaxies. Comparatively, more massive systems show a rather uniform negative metallicity gradient. The correlation between metallicity flattening and stellar mass for these systems results in p-values as low as 0.01. Independent of the mechanism having shaped the outer light profiles of these galaxies, stellar migration or a previous episode of star formation in a shrinking star-forming disk, it is clear that the imprint in their ionized-gas metallicity was different for low- and high-mass Type II galaxies. In the case of Type III disks, a positive correlation between the change in color and abundance gradient is found (the null hypothesis is ruled out with a p-value of 0.02), with the outer disks of Type III galaxies with masses ≤1010 M′ showing a weak color reddening or even a bluing. This is interpreted as primarily due to a mass downsizing effect on the population of Type III galaxies that recently experienced an enhanced inside-out growth, We acknowledge support from the Plan Nacional de Investigación y Desarrollo funding programs, AyA2010-15081, AyA2012-30717 and AyA2013-46724P, of Spanish Ministerio de Economía y Competitividad (MINECO). A.G.d.P. acknowledges the support from the FP7 Marie Curie Actions of the European Commission, via the Initial Training Network DAGAL under REA grant agreement PITNGA- 2011-289313. C.C.-T. thanks the support of the Spanish Ministerio de Educación, Cultura y Deporte by means of the FPU fellowship program. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. Support for L.G. is provided by the Ministry of Economy, Development, and Tourism’s Millennium Science Initiative through grant IC 120009, awarded to The Millennium Institute of Astrophysics, MAS. L.G. acknowledges support by CONIC YT through FONDECYT grant 3140566. S.F.S. thanks the CONACYT-125180 and DGAPA-IA100815 projects for providing him support in this study. J.M.A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild). P.P. is supported by FCT through the Investigador FCT Contract No. IF/01220/2013 and POPH/FSE (EC) by FEDER funding through the program COMPETE. He also acknowledges support by FCT under project FCOMP-01-0124-FEDER-029170 (Reference FCT PTDC/FISAST/ 3214/2012), funded by FCT-MEC (PIDDAC) and FEDER (COMPETE)
First survey of Wolf-Rayet star populations over the full extension of nearby galaxies observed with CALIFA
Biblos-e Archivo. Repositorio Institucional de la UAM
- Miralles-Caballero, D.
- Díaz Beltrán, Ángeles Isabel
- López-Sánchez, A. R.
- Rosales Ortega, F. Fabián
- Monreal-Ibero, Ana
- Pérez-Montero, E.
- Kehrig, C.
- García-Benito, R.
- Sánchez, S. F.
- Walcher, C. J.
- Galbany, L.
- Iglesias-Páramo, J.
- Vílchez, J. M.
- González, R. M.
- van de Ven, G.
- Barrera-Ballesteros, J.
- Lyubenova, M.
- Mast, D.
- Falcon-Barroso, J.
- Meidt, S.
- Mendoza, M. A.
- CALIFA Collaboration
Astronomy and Astrophysics 592 (2016): A105 reproduced with permission from Astronomy & Astrophysics, The search of extragalactic regions with conspicuous presence of Wolf-Rayet (WR) stars outside the Local Group is challenging task owing to the difficulty 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 procedure has been applied to a sample of nearby galaxies spanning a wide range of physical, morphological, and environmental properties. This technique allowed us to build the first catalogue of regions rich in WR stars with spatially resolved information, and enabled us to study the properties of these complexes in a two-dimensional (2D) context. The detection technique is based on the identification of the blue WR bump (around He iiλ4686 Å, mainly associated with nitrogen-rich WR stars; WN) and the red WR bump (around C ivλ5808 Å, mainly associated with carbon-rich WR stars; WC) using a pixel-by-pixel analysis that maximizes the number of independent regions within a given galaxy. We identified 44 WR-rich regions with blue bumps distributed in 25 out of a total of 558 galaxies. The red WR bump was identified only in 5 of those regions. Most of the WR regions are located within one effective radius from the galaxy centre, and around one-third are located within ~1 kpc or less from the centre. 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, such as potential candidates to 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 binary star channel (which could extend theWR phase up to 10 Myr), fast rotation, or other physical processes that cause the loss of observed Lyman continuum photons, very likely affect the derived WR properties, and hence should be considered when modelling the evolution of massive stars, D.M.C., A.I.D., and F.F.R.O. would like to acknowledge financial support provided by the project AYA2010-21887-C04-03 (former Ministerio de Ciencia e Innovación, Spain) as well as the exchange programme “Study of Emission-Line Galaxies with Integral-Field Spectroscopy” (SELGIFS, FP7- PEOPLE-2013-IRSES-612701), funded by the EU through the IRSES scheme. A.M.I. acknowledges support from Agence Nationale de la Recherche through the STILISM project (ANR-12-BS05-0016-02). R.G.D. acknowledges support through the project AYA2014-57490-P. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. 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
Proyecto: EC, EC/FP7, FP7/303912, 612701
Spatially resolved star formation main sequence of galaxies in the CALIFA survey
Biblos-e Archivo. Repositorio Institucional de la UAM
- Cano-Díaz, M.
- Ascasibar Sequeiros, Yago
- Sánchez-Blázquez, Patricia
Astrophysical Journal Letters 821.2 (2016): L26 reproduced by permission of the AAS, 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 (Mo yr-1 Kpc-2) and the stellar mass surface density in units of log (Mo 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, Financial support: M.C.D. and S.F.S.: DGAPA-UNAM funding; CONACyT-180125 and PAPIIT IA- 100815 projects. Z.S.: EU Marie Curie Career Integration Grant ”SteMaGE” PCIG12-GA-2012-326466. Y.A.: RyC- 2011-09461 and AYA2013-47742-C4-3-P projects from the Spanish MINECO and the SELGIFS programme, funded by the EU (FP7-PEOPLE-2013-IRSES-612701). C.J.W.: Marie Curie Career Integration Grant 303912. R.M.G.D.: AyA2014- 57490-P and J.A. P12-FQM2828 grants. J.F.B.: AYA2013- 48226-C3-1-P from the Spanish MINECO grant. L.G.: Millennium Science Initiative through grant IC120009, and by CONICYT through FONDECYT grant 3140566
Shape of the oxygen abundance profiles in CALIFA face-on spiral galaxies
Biblos-e Archivo. Repositorio Institucional de la UAM
- Sánchez-Menguiano, L.
- Sánchez, S. F.
- Pérez, I.
- Garcia-Benito, R.
- Husemann, B.
- Mast, D.
- Mendoza, A.
- Ruiz-Lara, T.
- Ascasibar Sequeiros, Yago
- Bland-Hawthorn, J.
- Cavichia, O.
- Díaz Beltrán, Ángeles Isabel
- Florido, E.
- Galbany, L.
- Gónzalez Delgado, R.M.
- Kehrig, C.
- Marino, R. A.
- Márquez, I.
- Masegosa, J.
- Méndez-Abreu, Jairo
- Mollá, M.
- Del Olmo, A.
- Pérez, E.
- Sánchez-Blázquez, Patricia
- Stanishev, V.
- Walcher, C.J.
- López-Sánchez, A. R.
- The Califa collaboration
Astronomy & Astrophysics 587 (2016): A70 reproduced with permission from Astronomy & Astrophysics, We measured the gas abundance profiles in a sample of 122 face-on spiral galaxies observed by the CALIFA survey and included all spaxels whose line emission was consistent with star formation. This type of analysis allowed us to improve the statistics with respect to previous studies, and to properly estimate the oxygen distribution across the entire disc to a distance of up to 3-4 disc effective radii (re). We confirm the results obtained from classical H ii region analysis. In addition to the general negative gradient, an outer flattening can be observed in the oxygen abundance radial profile. An inner drop is also found in some cases. There is a common abundance gradient between 0.5 and 2.0 re of αO/H =-0.075 dex/re with a scatter of σ = 0.016 dex/re when normalising the distances to the disc effective radius. By performing a set of Kolmogorov-Smirnov tests, we determined that this slope is independent of other galaxy properties, such as morphology, absolute magnitude, and the presence or absence of bars. In particular, barred galaxies do not seem to display shallower gradients, as predicted by numerical simulations. Interestingly, we find that most of thegalaxies in the sample with reliable oxygen abundance values beyond ~2 effective radii (57 galaxies) present a flattening of the abundance gradient in these outer regions. This flattening is not associated with any morphological feature, which suggests that it is a common property of disc galaxies. Finally, we detect a drop or truncation of the abundance in the inner regions of 27 galaxies in the sample; this is only visible for the most massive galaxies, We acknowledge financial support from the Spanish Ministerio de Economía y Competitividad (MINECO) via grant AYA2012-31935, and from the “Junta de Andalucía” local government through the FQM-108 project. We also acknowledge support to the ConaCyt funding program 180125. Y.A. acknowledges fi- nantial support from the Ramón y Cajal programme (RyC-2011-09461). Y.A. and A.I.D. acknowledge support from the project AYA2013-47742-C4-3-P from the Spanish MINECO, as well as the “Study of Emission-Line Galaxies with Integral-Field Spectroscopy” (SELGIFS) programme, funded by the EU (FP7- PEOPLE-2013-IRSES-612701). 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. LG acknowledges support by CONICYT through FONDECYT grant 3140566. R.M.G.D. acknowledges support from the Spanish grant AYA2014-57490-P, and from the “Junta de Andalucía” P12-FQM2828 project. RAM thanks the Spanish program of International Campus of Excellence Moncloa (CEI). IM and A.d.O. acknowledge support from the Spanish MINECO grant AYA2013-42227P. JMA acknowledges support from the European Research Council Starting Grant (SEDmorph, P.I. V. Wild). Support for MM has been provided by DGICYT grant AYA2013-47742-C4-4-P. PSB acknowledges support from the Ramón y Cajal programme, grant ATA2010-21322-C03-02 from the Spanish MINECO. CJW acknowledges support through the Marie Curie Career Grant Integration 303912
Warm ionized gas in CALIFA early-type galaxies: 2D emission-line patterns and kinematics for 32 galaxies
Digital.CSIC. Repositorio Institucional del CSIC
- Gomes, J. M.
- Papaderos, P.
- Kehrig, C.
- Vílchez Medina, José Manuel
- Lehnert, M.D.
- Sánchez, Sebastián F.
- Ziegler, B.
- Breda, I.
- Dos Reis, S. N.
- Iglesias-Páramo, J.
- Bland-Hawthorn, J.
- Galbany, Lluís
- Bomans, D. J.
- Rosales-Ortega, Fabián
- Cid Fernandes, Roberto
- Walcher, C. J.
- Falcón-Barroso, Jesús
- García-Benito, Rubén
- Márquez, Isabel
- Olmo, Ascensión del
- Masegosa, Josefa
- Mollá, M.
- Marino, R.A.
- González Delgado, Rosa M.
- López-Sánchez, A.R.
- The Califa, C.
Context. The morphological, spectroscopic, and kinematical properties of the warm interstellar medium (wim) in early-type galaxies (ETGs) hold key observational constraints to nuclear activity and the buildup history of these massive, quiescent systems. High-quality integral field spectroscopy (IFS) data with a wide spectral and spatial coverage, such as those from the CALIFA survey, oαer an unprecedented opportunity for advancing our understanding of the wim in ETGs. Aims. This article centers on a 2D investigation of the wim component in 32 nearby (<∼ 150 Mpc) ETGs from CALIFA, complementing a previous 1D analysis of the same sample. Methods. The analysis presented here includes Hα intensity and equivalent width (EW) maps and radial profiles, diagnostic emission-line ratios, and ionized-gas and stellar kinematics. It is supplemented by ratio maps, which are a more ecient means to quantify the role of photoionization by the post-AGB stellar component than alternative mechanisms (e.g., AGN, low-level star formation). Results. Confirming and strengthening our previous conclusions, we find that ETGs span a broad continuous sequence in the properties of their wim, exemplified by two characteristic classes. The first (type i) comprises systems with a nearly constant EW(Hα) in their extranuclear component, which quantitatively agrees with (but is no proof of) the hypothesis that photoionization by the post-AGB stellar component is the main driver of extended wim emission. The second class (type ii) stands for virtually wim-evacuated ETGs with a very low (0.5 Ã), outwardly increasing EW(Hα). These two classes appear indistinguishable from one another by their LINER-specific emission-line ratios in their extranuclear component. Here we extend the tentative classification we proposed previously by the type i+, which is assigned to a subset of type i ETGs exhibiting ongoing low-level star-forming activity in their periphery. This finding along with faint traces of localized star formation in the extranuclear component of several of our sample galaxies points to a non-negligible contribution by OB stars to the global ionizing photon budget in ETGs. Additionally, our data again highlight the diversity of ETGs in their gaseous and stellar kinematics. While in one half of our sample, gas and stars show similar (yet not necessarily identical) velocity patterns that are both dominated by rotation along the major galaxy axis, our analysis also documents several cases of kinematical decoupling between gas and stars, or rotation along the minor galaxy axis. We point out that the generally very low (<∼ 1) EW(Hα) of ETGs requires a careful quantitative assessment of potential observational and analysis biases in studies of their wim. With standard emission-line fitting tools, Balmer emission lines become progressively dificult to detect below an EW(Hα) ∼ 3 Ã, therefore our current understanding of the presence and 2D emission patterns and kinematics of the diαuse wim ETGs may be severely incomplete. We demonstrate that at the typical emission-line detection threshold of ∼2 Ã in previous studies, most of the extranuclear wim emission in an ETG may evade detection, which could in turn cause ETGs to be classified as entirely gas-devoid systems. Conclusions. This study adds further observational evidence for a considerable heterogeneity among ETGs with regard to the physical properties and 2D kinematics of their extended wim component, and it clearly shows that a comprehensive understanding of these systems requires IFS studies over their entire optical extent., This paper is based on data from the Calar Alto Legacy Integral Field Area Survey, CALIFA (http://califa.caha.es), funded by the Spanish Ministery of Science under grant ICTS-2009-10, and the Centro Astronomico Hispano-Aleman. JMG acknowledges support by Fundacao para a Ciencia e a Tecnologia (FCT) through the Fellowship SFRH/BPD/66958/2009 and POPH/FSE (EC) by FEDER funding through the program Programa Operacional de Factores de Competitividade (COMPETE). PP is supported by FCT through the Investigador FCT Contract No. IF/01220/2013 and POPH/FSE (EC) by FEDER funding through the program COMPETE. JMG, PP, IB and SNdR also acknowledge support by FCT under project FCOMP-01-0124-FEDER-029170 (Reference FCT PTDC/FIS-AST/3214/2012), funded by FCT-MEC (PIDDAC) and FEDER (COMPETE). They also acknowledge support by the exchange programme >Study of Emission-Line Galaxies with Integral-Field Spectroscopy> (SELGIFS, FP7-PEOPLE-2013-IRSES-612701), funded by the EU through the IRSES scheme. S.F.S. acknowledges support from CONACyT-180125 and PAPIIT-IA100815 grants. 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. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. R.G.B. is supported by the Spanish Ministerio de Ciencia e Innovacion under grant AYA2010-15081. R.A. Marino is funded by the Spanish program of International Campus of Excellence Moncloa (CEI). I.M. acknowledges financial support by the Junta de Andalucia through project TIC114, and the Spanish Ministry of Economy and Competitiveness (MINECO) through projects AYA2010-15169 and AYA2013-42227-P. A.d.O. acknowledges financial support from the Spanish grants AYA2010-15169 and AYA2013-42227-P. J.F.-B. acknowledges support from grant AYA2013-48226-C3-1-P from the Spanish Ministry of Economy and Competitiveness (MINECO). The star light project is supported by the Brazilian agencies CNPq, CAPES, and FAPESP. We benefited from stimulating discussions with several members of the CALIFA collaboration. This research made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration., Peer Reviewed
Spectroscopic aperture biases in inside-out evolving early-type galaxies from CALIFA
Digital.CSIC. Repositorio Institucional del CSIC
- Gomes, J. M.
- Papaderos, P.
- Vílchez Medina, José Manuel
- Kehrig, C.
- Iglesias-Páramo, J.
- Breda, I.
- Lehnert, M.D.
- Sánchez, Sebastián F.
- Ziegler, B.
- Dos Reis, S. N.
- Bland-Hawthorn, J.
- Galbany, Lluís
- Bomans, D. J.
- Rosales-Ortega, Fabián
- Walcher, C. J.
- García-Benito, Rubén
- Márquez, Isabel
- Olmo, Ascensión del
- Mollá, M.
- Marino, R.A.
- Catalán-Torrecilla, C.
- González Delgado, Rosa M.
- López-Sánchez, R.
- CALIFA Collaboration
Integral field spectroscopy (IFS) studies based on CALIFA survey data have recently revealed ongoing low-level star formation (SF) in the periphery of a small fraction (∼10%) of local early-type galaxies (ETGs), witnessing a still ongoing inside-out galaxy growth process. A distinctive property of the nebular component in these ETGs, classified i+, is a structure with two radial zones, the inner of which displays LINER emission with a Hα equivalent width EW(Hα) ≃ 1 Å, the outer (3 Å <EW(Hα) ≲ 20 Å) HII-region characteristics. Using CALIFA IFS data, we empirically demonstrate that the confinement of nebular emission to the galaxy periphery leads to a strong aperture (or, correspondingly, redshift) bias in spectroscopic single-fiber studies of type i+ ETGs: at low redshift (z ≲ 0.45), SDSS spectroscopy is restricted to the inner (SF-devoid LINER) zone, which causes the galaxies to be erroneously classified as >retired>, that is, systems entirely lacking SF, and whose faint nebular emissionis solely powered by the post-AGB stellar component. The SDSS aperture progressively encompasses the outer SF zone only at higher z, at which the galaxies are unambiguously classified as >composite SF/LINER>. We also empirically demonstrate that the principal effect of a decreasing spectroscopic aperture on the classification of i+ ETGs through standard [NII]/Hα vs. [OIII]/Hβ emission-line (BPT) ratios consists of a monotonic shift upward and to the right precisely along the upper right wing of the >seagull> distribution on the BPT plane, that is, along the pathway connecting composite SF/HII galaxies with AGN/LINERs. Motivated by these observational insights, we also investigate theoretically observational biases in aperture-limited studies of inside-out growing galaxies as a function of z. To this end, we devise a simple 1D model that involves an outward-propagating exponentially decreasing SF process since z ∼ 10 and reproduces the radial extent and two-zone EW(Hα) distribution of local i+ ETGs. By simulating the 3″ spectroscopic SDSS aperture in this model, we find that SDSS studies at z ≲ 1 are progressively restricted to the inner (SF-devoid LINER) zone and miss an increasingly larger portion of the Hα-emitting periphery. This leads to the incorrect spectroscopic classification of these inside-out assembling galaxies as retired ETG/LINERs and also to a severe underestimation of their total star formation rate (SFR) in a manner inversely related to z. More specifically, the SFR inferred from the Hα luminosity registered within the SDSS fiber is reduced by 50% at z ∼ 0.86, reaching only 0.1% of its integral value at z = 0.1. We argue that the aperture-driven biases described above pertain to any morphological analog of i+ ETGs (e.g., SF-quiescent bulges within star-forming disks), regardless of whether it is viewed from the perspective of inside-out growth or inside-out SF quenching, and might be of considerable relevance to galaxy taxonomy and studies of the cosmic SFR density as a function of z., This paper is based on data from the Calar Alto Legacy Integral Field Area Survey, CALIFA (http://califa.caha.es), funded by the Spanish Ministery of Science under grant ICTS-2009-10, and the Centro Astronomico Hispano-Aleman. JMG acknowledges support by Fundacao para a Ciencia e a Tecnologia (FCT) through the Fellowship SFRH/BPD/66958/2009 and POPH/FSE (EC) by FEDER funding through the program Programa Operacional de Factores de Competitividade (COMPETE). P.P. is supported by FCT through the Investigador FCT Contract No. IF/01220/2013 and POPH/FSE (EC) by FEDER funding through the program COMPETE. J.M.G., P.P., I.B. and S.N.d.R. acknowledge support by FCT under project FCOMP-01-0124-FEDER-029170 (Reference FCT PTDC/FIS-AST/3214/2012), funded by FCT-MEC (PIDDAC) and FEDER (COMPETE). They also acknowledge support by the exchange programme >Study of Emission-Line Galaxies with Integral-Field Spectroscopy> (SELGIFS, FP7-PEOPLE-2013-IRSES-612701), funded by the EU through the IRSES scheme. SFS acknowledges support from CONACyT-180125 and PAPIIT-IA100815 grants. Support for LG 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. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. I.M. acknowledges financial support by the Junta de Andalucia through project TIC114, and the Spanish Ministry of Economy and Competitiveness (MINECO) through projects AYA2010-15169 and AYA2013-42227-P. R.A. Marino is funded by the Spanish program of International Campus of Excellence Moncloa (CEI). This research made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration., Peer Reviewed
Spiral-like star-forming patterns in CALIFA early-type galaxies
Digital.CSIC. Repositorio Institucional del CSIC
- Gomes, J. M.
- Papaderos, P.
- Vílchez Medina, José Manuel
- Kehrig, C.
- Iglesias-Páramo, J.
- Breda, I.
- Lehnert, M.D.
- Sánchez, Sebastián F.
- Ziegler, B.
- Dos Reis, S. N.
- Bland-Hawthorn, J.
- Galbany, Lluís
- Bomans, D. J.
- Rosales-Ortega, Fabián
- Walcher, C. J.
- García-Benito, Rubén
- Márquez, Isabel
- Olmo, Ascensión del
- Mollá, M.
- Marino, R.A.
- Catalán-Torrecilla, C.
- González Delgado, Rosa M.
- López-Sánchez, A.R.
Based on a combined analysis of SDSS imaging and CALIFA integral field spectroscopy data, we report on the detection of faint (24 <μ mag/□″< 26) star-forming spiral-arm-like features in the periphery of three nearby early-type galaxies (ETGs). These features are of considerable interest because they document the still ongoing inside-out growth of some local ETGs and may add valuable observational insight into the origin and evolution of spiral structure in triaxial stellar systems. A characteristic property of the nebular component in the studied ETGs, classified i+, is a two-radial-zone structure, with the inner zone that displays faint (EW(Hα) ≃ 1 Å) low-ionization nuclear emission-line region (LINER) properties, and the outer one (3 Å <EW(Hα)≲ 20 Å) Hii-region characteristics. This spatial segregation of nebular emission in two physically distinct concentric zones calls for an examination of aperture effects in studies of type i+ ETGs with single-fiber spectroscopic data., This paper is based on data from the Calar Alto Legacy Integral Field Area Survey, CALIFA (http://califa.caha.es), funded by the Spanish Ministery of Science under grant ICTS-2009-10, and the Centro Astronomico Hispano-Aleman. J.M.G. acknowledges support by Fundacao para a Ciencia e a Tecnologia (FCT) through the Fellowship SFRH/BPD/66958/2009 and POPH/FSE (EC) by FEDER funding through the program Programa Operacional de Factores de Competitividade (COMPETE). P.P. is supported by FCT through the Investigador FCT Contract No. IF/01220/2013 and POPH/FSE (EC) by FEDER funding through the program COMPETE. J.M.G. and P.P. acknowledge support by FCT under project FCOMP-01-0124-FEDER-029170 (Ref. PTDC/FIS-AST/3214/2012), funded by FCT-MEC (PIDDAC) and FEDER (COMPETE) and the exchange programme >Study of Emission-Line Galaxies with Integral-Field Spectroscopy> (SELGIFS, FP7-PEOPLE-2013-IRSES-612701), funded by the EU through the IRSES scheme. S.F.S. acknowledges support from CONACyT-180125 and PAPIIT-IA100815 grants. 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. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. I.M. acknowledges financial support by the Junta de Andalucia through project TIC114, and the Spanish Ministry of Economy and Competitiveness (MINECO) through projects AYA2010-15169 and AYA2013-42227-P. R.A. Marino is funded by the Spanish program of International Campus of Excellence Moncloa (CEI). This research made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration., Peer Reviewed
The CALIFA survey across the Hubble sequence: Spatially resolved stellar population properties in galaxies
Digital.CSIC. Repositorio Institucional del CSIC
- González Delgado, Rosa M.
- García-Benito, Rubén
- Pérez Jiménez, Enrique
- Cid Fernandes, Roberto
- Amorim, A. L. de
- Cortijo Ferrero, Clara
- Lacerda, E.A.D.
- López Fernández, R.
- Vale-Asari, N.
- Sánchez, Sebastián F.
- Mollá, M.
- Ruiz-Lara, T.
- Sánchez-Blázquez, P.
- Walcher, C. J.
- Alves, João
- Aguerri, J.A.L.
- Bekeraité, S.
- Bland-Hawthorn, J.
- Galbany, Lluís
- Gallazzi, A.
- Husemann, B.
- Iglesias-Páramo, J.
- Kalinova, V.
- López-Sánchez, A.R.
- Marino, R.A.
- Márquez, Isabel
- Masegosa, Josefa
- Mast, D.
- Méndez-Abreu, J.
- Mendoza, A.
- Olmo, Ascensión del
- Pérez, I.
- Quirrenbach, Andreas
- Zibetti, S.
- CALIFA Collaboration
© ESO, 2015. Various different physical processes contribute to the star formation and stellar mass assembly histories of galaxies. One important approach to understanding the significance of these different processes on galaxy evolution is the study of the stellar population content of today's galaxies in a spatially resolved manner. The aim of this paper is to characterize in detail the radial structure of stellar population properties of galaxies in the nearby universe, based on a uniquely large galaxy sample, considering the quality and coverage of the data. The sample under study was drawn from the CALIFA survey and contains 300 galaxies observed with integral field spectroscopy. These cover a wide range of Hubble types, from spheroids to spiral galaxies, while stellar masses range from M<inf>Black star</inf> ∼ 10<sup>9</sup> to 7 × 10<sup>11</sup> M<inf>⊙</inf>. We apply the fossil record method based on spectral synthesis techniques to recover the following physical properties for each spatial resolution element in our target galaxies: the stellar mass surface density (μ<inf>Black star</inf>), stellar extinction (A<inf>V</inf>), light-weighted and mass-weighted ages ('log age'<inf>L</inf>, 'log age'<inf>M</inf>), and mass-weighted metallicity ('log Z<inf>Black star</inf>'<inf>M</inf>). To study mean trends with overall galaxy properties, the individual radial profiles are stacked in seven bins of galaxy morphology (E, S0, Sa, Sb, Sbc, Sc, and Sd). We confirm that more massive galaxies are more compact, older, more metal rich, and less reddened by dust. Additionally, we find that these trends are preserved spatially with the radial distance to the nucleus. Deviations from these relations appear correlated with Hubble type: earlier types are more compact, older, and more metal rich for a given M<inf>Black star</inf>, which is evidence that quenching is related to morphology, but not driven by mass. Negative gradients of 'log age'<inf>L</inf> are consistent with an inside-out growth of galaxies, with the largest 'log age'<inf>L</inf> gradients in Sb-Sbc galaxies. Further, the mean stellar ages of disks and bulges are correlated and with disks covering a wider range of ages, and late-type spirals hosting younger disks. However, age gradients are only mildly negative or flat beyond R ∼ 2 HLR (half light radius), indicating that star formation is more uniformly distributed or that stellar migration is important at these distances. The gradients in stellar mass surface density depend mostly on stellar mass, in the sense that more massive galaxies are more centrally concentrated. Whatever sets the concentration indices of galaxies obviously depends less on quenching/morphology than on the depth of the potential well. There is a secondary correlation in the sense that at the same M<inf>Black star</inf> early-type galaxies have steeper gradients. The μ<inf>Black star</inf> gradients outside 1 HLR show no dependence on Hubble type. We find mildly negative 'log Z<inf>Black star</inf>'<inf>M</inf> gradients, which are shallower than predicted from models of galaxy evolution in isolation. In general, metallicity gradients depend on stellar mass, and less on morphology, hinting that metallicity is affected by both - the depth of the potential well and morphology/quenching., Support from the Spanish Ministerio de Economia y Competitividad, through projects AYA2010-15081 (PI R.G.D.), and Junta de Andalucia FQ1580 (PI R.G.D.), AYA2010-22111-C03-03, and AYA2010-10904E (S.F.S.). We also thank the Viabilidad, Diseno, Acceso y Mejora funding program, ICTS-2009-10, for funding the data acquisition of this project. R.C.F. thanks the hospitality of the IAA and the support of CAPES and CNPq. R.G.D. acknowledges the support of CNPq (Brazil) through Programa Ciencia sem Fronteiras (401452/2012-3). A.G. acknowledges support from EU FP7/2007-2013 under grant agreement n.267251 (AstroFIt) and from the EU Marie Curie Integration Grant >SteMaGE> Nr. PCIG12-GA-2012-326466. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. E.P. acknowledges support from the Guillermo Haro program at INAOE. 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. J.I.P. acknowledges financial support from the Spanish MINECO under grant AYA2010-21887-C04-01 and from Junta de Andalucia Excellence Project PEX2011-FQM7058. I.M., J.M. and A.d.O. acknowledge support from the project AYA2013-42227-P. RAM is funded by the Spanish program of International Campus of Excellence Moncloa (CEI). J.M. A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild)., Peer Reviewed
Outer-disk reddening and gas-phase metallicities: The CALIFA connection
Digital.CSIC. Repositorio Institucional del CSIC
- Marino, R.A.
- Sánchez, Sebastián F.
- Cardiel, Nicolás
- Vílchez Medina, José Manuel
- Kehrig, C.
- González Delgado, Rosa M.
- García-Benito, Rubén
- Mast, Damián
- Iglesias-Páramo, J.
- Bland-Hawthorn, J.
Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie Heidelberg and the Instituto de Astrofísica de Andalucía (CSIC )., CALIFA Team: et al., We study, for the first time in a statistically significant and well-defined sample, the relation between the outer-disk ionized-gas metallicity gradients and the presence of breaks in the surface brightness profiles of disk galaxies. Sloan Digital Sky Survey (SDSS) g′- and r′-band surface brightness, (g′ - r′) color, and ionized-gas oxygen abundance profiles for 324 galaxies within the Calar Alto Legacy Integral Field Area (CALIFA) survey are used for this purpose. We perform a detailed light-profile classification, finding that 84% of our disks show down- or up-bending profiles (Type II and Type III, respectively), while the remaining 16% are well fitted by one single exponential (Type I). The analysis of the color gradients at both sides of this break shows a U-shaped profile for most Type II galaxies with an average minimum (g′ - r′) color of ∼ 0.5mag and an ionized-gas metallicity flattening associated with it only in the case of low-mass galaxies. Comparatively, more massive systems show a rather uniform negative metallicity gradient. The correlation between metallicity flattening and stellar mass for these systems results in p-values as low as 0.01. Independent of the mechanism having shaped the outer light profiles of these galaxies, stellar migration or a previous episode of star formation in a shrinking star-forming disk, it is clear that the imprint in their ionized-gas metallicity was different for low- and high-mass Type II galaxies. In the case of Type III disks, a positive correlation between the change in color and abundance gradient is found (the null hypothesis is ruled out with a p-value of 0.02), with the outer disks of Type III galaxies with masses ≤10 M′ showing a weak color reddening or even a bluing. This is interpreted as primarily due to a mass downsizing effect on the population of Type III galaxies that recently experienced an enhanced inside-out growth., R. A. Marino is funded by the Spanish program of International Campus of Excellence Moncloa (CEI).We acknowledge support from the Plan Nacional de Investigación y Desarrollo funding programs, AyA2010-15081, AyA2012-30717 and AyA2013-46724P, of Spanish Ministerio de Economía y Competitividad (MINECO). A.G.d.P. acknowledges
the support from the FP7 Marie Curie Actions of the European Commission, via the Initial Training Network DAGAL under REA grant agreement PITNGA-2011-289313.
C.C.-T. thanks the support of the Spanish Ministerio de Educación, Cultura y Deporte by means of the FPU fellowship program. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. Support for L.G. is provided by the Ministry of Economy, Development, and Tourism’s Millennium Science Initiative through grant IC 120009, awarded to The Millennium Institute of Astrophysics, MAS. L.G. acknowledges support by CONICYT through FONDECYT grant 3140566. S.F.S. thanks the CONACYT-125180 and DGAPA-IA100815 projects for providing him support in this study. J.M.A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild). P.P. is supported by FCT through the Investigador FCT Contract No. IF/01220/2013 and POPH/FSE (EC) by FEDER funding through the program COMPETE. He also acknowledges support by FCT under project FCOMP-01-0124-FEDER-029170 (Reference FCT PTDC/FISAST/3214/2012), funded by FCT-MEC (PIDDAC) and FEDER (COMPETE)., Peer Reviewed
the support from the FP7 Marie Curie Actions of the European Commission, via the Initial Training Network DAGAL under REA grant agreement PITNGA-2011-289313.
C.C.-T. thanks the support of the Spanish Ministerio de Educación, Cultura y Deporte by means of the FPU fellowship program. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. Support for L.G. is provided by the Ministry of Economy, Development, and Tourism’s Millennium Science Initiative through grant IC 120009, awarded to The Millennium Institute of Astrophysics, MAS. L.G. acknowledges support by CONICYT through FONDECYT grant 3140566. S.F.S. thanks the CONACYT-125180 and DGAPA-IA100815 projects for providing him support in this study. J.M.A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild). P.P. is supported by FCT through the Investigador FCT Contract No. IF/01220/2013 and POPH/FSE (EC) by FEDER funding through the program COMPETE. He also acknowledges support by FCT under project FCOMP-01-0124-FEDER-029170 (Reference FCT PTDC/FISAST/3214/2012), funded by FCT-MEC (PIDDAC) and FEDER (COMPETE)., Peer Reviewed
First survey of Wolf-Rayet star populations over the full extension of nearby galaxies observed with CALIFA
Digital.CSIC. Repositorio Institucional del CSIC
- Miralles-Caballero, D.
- Pérez Montero, Enrique
- Kehrig, C.
- García-Benito, Rubén
- Sánchez, S.F.
- Iglesias-Páramo, J.
- Vílchez Medina, José Manuel
- González Delgado, Rosa M.
- Mast, Damián
- Mendoza, M. A.
The search of extragalactic regions with conspicuous presence of Wolf-Rayet (WR) stars outside the Local Group is challenging task owing to the difficulty 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 procedure has been applied to a sample of nearby galaxies spanning a wide range of physical, morphological, and environmental properties. This technique allowed us to build the first catalogue of regions rich in WR stars with spatially resolved information, and enabled us to study the properties of these complexes in a two-dimensional (2D) context. The detection technique is based on the identification of the blue WR bump (around He iiλ4686 Å, mainly associated with nitrogen-rich WR stars; WN) and the red WR bump (around C ivλ5808 Å, mainly associated with carbon-rich WR stars; WC) using a pixel-by-pixel analysis that maximizes the number of independent regions within a given galaxy. We identified 44 WR-rich regions with blue bumps distributed in 25 out of a total of 558 galaxies. The red WR bump was identified only in 5 of those regions. Most of the WR regions are located within one effective radius from the galaxy centre, and around one-third are located within ~1 kpc or less from the centre. 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, such as potential candidates to 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 binary star channel (which could extend theWR phase up to 10 Myr), fast rotation, or other physical processes that cause the loss of observed Lyman continuum photons, very likely affect the derived WR properties, and hence should be considered when modelling the evolution of massive stars. © 2016 ESO., D.M.C., A.I.D., and F.F.R.O. would like to acknowledge financial support provided by the project AYA2010-21887-C04-03 (former Ministerio de Ciencia e Innovacion, Spain) as well as the exchange programme >Study of Emission-Line Galaxies with Integral-Field Spectroscopy> (SELGIFS, FP7-PEOPLE-2013-IRSES-612701), funded by the EU through the IRSES scheme. A.M.I. acknowledges support from Agence Nationale de la Recherche through the STILISM project (ANR-12-BS05-0016-02). R.G.D. acknowledges support through the project AYA2014-57490-P. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912, Peer Reviewed
Nearby supernova host galaxies from the CALIFA survey: II. Supernova environmental metallicity
Digital.CSIC. Repositorio Institucional del CSIC
- Galbany, Lluís
- García-Benito, Rubén
- González Delgado, Rosa M.
- Kehrig, C.
- Pérez Jiménez, Enrique
- Vílchez Medina, José Manuel
The metallicity of a supernova progenitor, together with its mass, is one of the main parameters that can rule the progenitor's fate. We present the second study of nearby supernova (SN) host galaxies (0.005 <z< 0.03) using integral field spectroscopy (IFS) from the CALIFA survey. We analyze the metallicity of 115 galaxies, which hosted 132 SNe within and 10 SNe outside the field of view (FoV) of the instrument. Another 18 galaxies, which hosted only SNe outside the FoV, were also studied. Using the O3N2 calibrator that was described elsewhere, we found no statistically significant differences between the gas-phase metallicities at the locations of the three main SN types - Ia, Ib/c and II; they all have 12 + log (O/H) ≃ 8.50 within 0.02 dex. The total galaxy metallicities are also very similar, and we argue that the reason is that our sample only consists of SNe discovered in massive galaxies (log (M/M) > 10 dex) by targeted searches. We neither found evidence that the metallicity at the SN location differs from the average metallicity at the galactocentric distance of the SNe. By extending our SN sample with published metallicities at the SN location, we are able to study the metallicity distributions for all SN subtypes split into SN discovered in targeted and untargeted searches. We confirm a bias toward higher host masses and metallicities in the targeted searches. By combining data from targeted and untargeted searches, we found a sequence from higher to lower local metallicity: SN Ia, Ic, and II show the highest metallicity, which is significantly higher than those of SN Ib, IIb, and Ic-BL. Our results support the scenario according to which SN Ib result from binary progenitors. Additionally, at least part of the SN Ic are the result of single massive stars that were stripped of their outer layers by metallicity-driven winds. We studied several proxies of the local metallicity that are frequently used in the literature and found that the total host metallicity allows estimating the metallicity at the SN location with an accuracy better than 0.08 dex and very small bias. In addition, weak AGNs that cannot be seen in the total spectrum may weakly bias (by 0.04 dex) the metallicity estimate that is derived from the galaxy-integrated spectrum. © ESO, 2016., This work was partly funded by FCT with the research grant PTDC/CTE-AST/112582/2009. Support for L.G. is partially provided by FCT, by CONICYT through FONDECYT grant 3140566, and from the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC12009, awarded to The Millennium Institute of Astrophysics (MAS). V.S. acknowledges financial support from Fundacao para a Ciencia e a Tecnologia (FCT) under program Ciencia 2008. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912., Peer Reviewed
Proyecto: EC/FP7/303912
Stellar kinematics across the Hubble sequence in the CALIFA survey: general properties and aperture corrections
Digital.CSIC. Repositorio Institucional del CSIC
- Falcón-Barroso, Jesús
- García-Benito, Rubén
- González Delgado, Rosa M.
- Márquez, Isabel
- Pérez Jiménez, Enrique
- the CALIFA collaboration
J. Falcón-Barroso et. al., We present the stellar kinematic maps of a large sample of galaxies from the integral-field spectroscopic survey CALIFA. The sample comprises 300 galaxies displaying a wide range of morphologies across the Hubble sequence, from ellipticals to late-type spirals. This dataset allows us to homogeneously extract stellar kinematics up to several effective radii. In this paper, we describe the level of completeness of this subset of galaxies withrespect to the full CALIFA sample, as well as the virtues and limitations of the kinematic extraction compared to other well-known integral-field surveys. In addition, we provide averaged integrated velocity dispersion radial profiles for different galaxy types, which are particularly useful to apply aperture corrections for single aperture measurements or poorly resolved stellar kinematics of high-redshift sources. The work presented in this paper sets the basis for the study of more general properties of galaxies that will be explored in subsequent papers of the survey.© ESO, 2016., J.F.-B. from grant AYA2013-48226-C3-1-P from the Spanish Ministry of Economy and Competitiveness (MINECO). J.F.-B. and G.v.d.V. from the FP7 Marie Curie Actions of the European Commission, via the Initial Training Network DAGAL under REA grant agreement number 289313. J.M.-A. and V.W. acknowledge support from the European Research Council Starting Grant (SEDMorph P.I. V. Wild). P.S.-B. acknowledge financial support from the BASAL CATA Center for Astrophysics and Associated Technologies through grant PFB-06. R.M.G.D. from grant AYA2014-57490-P. R.G.-B, R.M.G.D. and E.P. acknowledge support from the project JA-FQM-2828. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. L.G. from the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009 awarded to The Millennium Institute of Astrophysics (MAS), and CONICYT through FONDECYT grant 3140566. I.M. from grant AYA2013-42227-P., Peer Reviewed
IMF shape constraints from stellar populations and dynamics from CALIFA
Digital.CSIC. Repositorio Institucional del CSIC
- Lyubenova, M.
- García-Benito, Rubén
- González Delgado, Rosa M.
- CALIFA Collaboration
M. Lyubenova et. al., In this paper, we describe how we use stellar dynamics information to constrain the shape of the stellar initial mass function (IMF) in a sample of 27 early-type galaxies from the CALIFA survey. We obtain dynamical and stellar mass-to-light ratios, ¿<SUB>dyn</SUB> and ¿<SUB>*</SUB>, over a homogenous aperture of 0.5 R<SUB>e</SUB>. We use the constraint ¿<SUB>dyn</SUB>¿¿<SUB>*</SUB> to test two IMF shapes within the framework of the extended MILES stellar population models. We rule out a single power-law IMF shape for 75 per cent of the galaxies in our sample. Conversely, we find that a double power-law IMF shape with a varying high-mass end slope is compatible (within 1¿) with 95 per cent of the galaxies. We also show that dynamical and stellar IMF mismatch factors give consistent results for the systematic variation of the IMF in these galaxies. © 2016, Published by Oxford University Press on behalf of the Royal Astronomical Society., This Paper is based on data obtained by the CALIFA survey, funded by the Spanish Ministry of Science under grant ICTS-2009-10, and the CAHA. IMN and JFB acknowledge funding from grant AYA2013-48226-C3-1-P from the Spanish Ministry of Economy and Competitiveness (MINECO) and, together with and GvdV, from the FP7 Marie Curie Actions via the ITN DAGAL (grant 289313). CJW acknowledges support through the Marie Curie Career Integration Grant 303912. Support for LG 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), and CONICYT through FONDECYT grant 3140566. RGD acknowledges support from AyA2014-57490-P. JMA acknowledges support from the ERC Starting Grant (SEDmorph; P.I. V. Wild)., Peer Reviewed
KMOS view of the Galactic centre: I. Young stars are centrally concentrated
Digital.CSIC. Repositorio Institucional del CSIC
- Feldmeier-Krause, A.
- Neumayer, N.
- Schödel, Rainer
- Seth, A.
- Hilker, M.
- De Zeeuw, P.T.
- Kuntschner, H.
- Walcher, C.J.
- Lützgendorf, N.
- Kissler-Patig, M.
Context. The Galactic centre hosts a crowded, dense nuclear star cluster with a half-light radius of 4 pc. Most of the stars in the Galactic centre are cool late-type stars, but there are also ≠100 hot early-type stars in the central parsec of the Milky Way. These stars are only 3-8 Myr old. Aims. Our knowledge of the number and distribution of early-type stars in the Galactic centre is incomplete. Only a few spectroscopic observations have been made beyond a projected distance of 0.5 pc of the Galactic centre. The distribution and kinematics of early-type stars are essential to understand the formation and growth of the nuclear star cluster. Methods. We cover the central >4 pc (0.75 sq. arcmin) of the Galactic centre using the integral-field spectrograph KMOS (VLT). We extracted more than 1000 spectra from individual stars and identified early-type stars based on their spectra. Results. Our data set contains 114 bright early-type stars: 6 have narrow emission lines, 23 are Wolf-Rayet stars, 9 stars have featureless spectra, and 76 are O/B type stars. Our wide-field spectroscopic data confirm that the distribution of young stars is compact, with 90% of the young stars identified within 0.5 pc of the nucleus. We identify 24 new O/B stars primarily at large radii. We estimate photometric masses of the O/B stars and show that the total mass in the young population is ≠12 000 M. The O/B stars all appear to be bound to the Milky Way nuclear star cluster, while less than 30% belong to the clockwise rotating disk. We add one new star to the sample of stars affiliated with this disk. Conclusions. The central concentration of the early-type stars is a strong argument that they have formed in situ. An alternative scenario, in which the stars formed outside the Galactic centre in a cluster that migrated to the centre, is refuted. A large part of the young O/B stars is not on the disk, which either means that the early-type stars did not all form on the same disk or that the disk is dissolving rapidly.© ESO, 2015., This research was supported by the DFG cluster of excellence Origin and Structure of the Universe (www.universe-cluster.de). C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912., Peer Reviewed
Proyecto: EC/FP7/303912