Browsing by Author "Monaco, L."
Now showing 1 - 20 of 21
Results Per Page
Sort Options
- ItemCAPOS: The bulge Cluster APOgee Survey. I. Overview and initial ASPCAP results(2021) Geisler, D.; Villanova, S.; O'Connell, J. E.; Cohen, R. E.; Moni Bidin, C.; Fernández-Trincado, J. G.; Muñoz, C.; Minniti, D.; Zoccali, M.; Rojas-Arriagada, A.; Contreras Ramos, R.; Catelan, Márcio; Mauro, F.; Cortés, C.; Ferreira Lopes, C. E.; Arentsen, A.; Starkenburg, E.; Martin, N. F.; Tang, B.; Parisi, C.; Alonso-García, J.; Gran, F.; Cunha, K.; Smith, V.; Majewski, S. R.; Jönsson, H.; García-Hernández, D. A.; Horta, D.; Mészáros, S.; Monaco, L.; Monachesi, A.; Muñoz, R. R.; Brownstein, J.; Beers, T. C.; Lane, R. R.; Barbuy, B.; Sobeck, J.; Henao, L.; González-Díaz, D.; Miranda, R. E.; Reinarz, Y.; Santander, T. A.Context. Bulge globular clusters (BGCs) are exceptional tracers of the formation and chemodynamical evolution of this oldest Galactic component. However, until now, observational difficulties have prevented us from taking full advantage of these powerful Galactic archeological tools. Aims: CAPOS, the bulge Cluster APOgee Survey, addresses this key topic by observing a large number of BGCs, most of which have only been poorly studied previously. Even their most basic parameters, such as metallicity, [α/Fe], and radial velocity, are generally very uncertain. We aim to obtain accurate mean values for these parameters, as well as abundances for a number of other elements, and explore multiple populations. In this first paper, we describe the CAPOS project and present initial results for seven BGCs. Methods: CAPOS uses the APOGEE-2S spectrograph observing in the H band to penetrate obscuring dust toward the bulge. For this initial paper, we use abundances derived from ASPCAP, the APOGEE pipeline. Results: We derive mean [Fe/H] values of −0.85 ± 0.04 (Terzan 2), −1.40 ± 0.05 (Terzan 4), −1.20 ± 0.10 (HP 1), −1.40 ± 0.07 (Terzan 9), −1.07 ± 0.09 (Djorg 2), −1.06 ± 0.06 (NGC 6540), and −1.11 ± 0.04 (NGC 6642) from three to ten stars per cluster. We determine mean abundances for eleven other elements plus the mean [α/Fe] and radial velocity. CAPOS clusters significantly increase the sample of well-studied Main Bulge globular clusters (GCs) and also extend them to lower metallicity. We reinforce the finding that Main Bulge and Main Disk GCs, formed in situ, have [Si/Fe] abundances slightly higher than their accreted counterparts at the same metallicity. We investigate multiple populations and find our clusters generally follow the light-element (anti)correlation trends of previous studies of GCs of similar metallicity. We finally explore the abundances of the iron-peak elements Mn and Ni and compare their trends with field populations. Conclusions: CAPOS is proving to be an unprecedented resource for greatly improving our knowledge of the formation and evolution of BGCs and the bulge itself....
- ItemChemical abundances of giant stars in NGC 5053 and NGC 5634, two globular clusters associated with the Sagittarius dwarf spheroidal galaxy?(EDP SCIENCES S A, 2015) Sbordone, L.; Monaco, L.; Moni Bidin, C.; Bonifacio, P.; Villanova, S.; Bellazzini, M.; Ibata, R.; Chiba, M.; Geisler, D.; Caffau, E.; Duffau, S.Context. The tidal disruption of the Sagittarius dwarf spheroidal galaxy (Sgr dSph) is producing the most prominent substructure in the Milky Way (MW) halo, the Sagittarius Stream. Aside from field stars, it is suspected that the Sgr dSph has lost a number of globular clusters (GC). Many Galactic GC are thought to have originated in the Sgr dSph. While for some candidates an origin in the Sgr dSph has been confirmed owing to chemical similarities, others exist whose chemical composition has never been investigated.
- ItemDetailed abundances in stars belonging to ultra-faint dwarf spheroidal galaxies(2012) François, P.; Monaco, L.; Villanova, S.; Catelan, Márcio; Bonifacio, P.; Bellazzini, M.; Moni Bidin, C.; Marconi, G.; Geisler, D.; Sbordone, L.We report preliminary results concerning the detailed chemical composition of metal poor stars belonging to close ultra-faint dwarf galaxies (hereafter UfDSphs). The abundances have been determined thanks to spectra obtained with X-Shooter, a high efficiency spectrograph installed on one of the ESO VLT units. The sample of ultra-faint dwarf spheroidal stars have abundance ratios slightly lower to what is measured in field halo star of the same metallicity. We did not find extreme abundances in our Hercules stars as the one found by Koch for his 2 Hercules stars. The synthesis of the neutron capture elements Ba and Sr seems to originate from the same nucleosynthetic process in operation during the early stages of the galactic evolution....
- ItemLithium-rich giants in the Galactic thick disk(2011) Monaco, L.; Zoccali, Manuela
- ItemThe Gaia-ESO Survey Mg-Al anti-correlation in iDR4 globular clusters(EDP SCIENCES S A, 2017) Pancino, E.; Romano, D.; Tang, B.; Tautvaisiene, G.; Casey, A. R.; Gruyters, P.; Geisler, D.; San Roman, I.; Randich, S.; Alfaro, E. J.; Bragaglia, A.; Flaccomio, E.; Korn, A. J.; Recio Blanco, A.; Smiljanic, R.; Carraro, G.; Bayo, A.; Costado, M. T.; Damiani, F.; Jofre, P.; Lardo, C.; de laverny, P.; Monaco, L.; Morbidelli, L.; Sbordone, L.; Sousa, S. G.; Villanova, S.We use Gaia-ESO (GES) Survey iDR4 data to explore the Mg-Alanti-correlation in globular clusters that were observed as calibrators, as a demonstration of the quality of Gaia-ESO Survey data and analysis. The results compare well with the available literature, within 0.1 dex or less, after a small (compared to the internal spreads) off set between the UVES and GIRAFFE data of 0.10-0.15 dex was taken into account. In particular, for the first time we present data for NGC 5927, which is one of the most metal-rich globular clusters studied in the literature so far with [Fe/H] = -0.39 +/- 0.04 dex; this cluster was included to connect with the open cluster regime in the Gaia-ESO Survey internal calibration. The extent and shape of the Mg-Al anti-correlation provide strong constraints on the multiple population phenomenon in globular clusters. In particular, we studied the dependency of the Mg-Al anti-correlation extension with metallicity, present-day mass, and age of the clusters, using GES data in combination with a large set of homogenized literature measurements. We find a dependency with both metallicity and mass, which is evident when fitting for the two parameters simultaneously, but we do not find significant dependency with age. We confirm that the Mg-Al anti-correlation is not seen in all clusters, but disappears for the less massive or most metal-rich clusters. We also use our data set to see whether a normal anti-correlation would explain the low [Mg/ff] observed in some extragalactic globular clusters, but find that none of the clusters in our sample can reproduce it; a more extreme chemical composition, such as that of NGC 2419, would be required. We conclude that GES iDR4 data already meet the requirements set by the main survey goals and can be used to study globular clusters in detail, even if the analysis procedures were not specifically designed for them.
- ItemThe Gaia-ESO Survey: a quiescent Milky Way with no significant dark/stellar accreted disc(a similar to...)(OXFORD UNIV PRESS, 2015) Ruchti, G. R.; Read, J. I.; Feltzing, S.; Serenelli, A. M.; McMillan, P.; Lind, K.; Bensby, T.; Bergemann, M.; Asplund, M.; Vallenari, A.; Flaccomio, E.; Pancino, E.; Korn, A. J.; Recio Blanco, A.; Bayo, A.; Carraro, G.; Costado, M. T.; Damiani, F.; Heiter, U.; Hourihane, A.; Jofre, P.; Kordopatis, G.; Lardo, C.; de Laverny, P.; Monaco, L.; Morbidelli, L.; Sbordone, L.; Worley, C. C.; Zaggia, S.According to our current cosmological model, galaxies like the Milky Way are expected to experience many mergers over their lifetimes. The most massive of the merging galaxies will be dragged towards the disc plane, depositing stars and dark matter into an accreted disc structure. In this work, we utilize the chemodynamical template developed in Ruchti et al. to hunt for accreted stars. We apply the template to a sample of 4675 stars in the third internal data release from the Gaia-ESO Spectroscopic Survey. We find a significant component of accreted halo stars, but find no evidence of an accreted disc component. This suggests that the Milky Way has had a rather quiescent merger history since its disc formed some 8-10 billion years ago and therefore possesses no significant dark matter disc.
- ItemThe Gaia-ESO Survey: Empirical determination of the precision of stellar radial velocities and projected rotation velocities(EDP SCIENCES S A, 2015) Jackson, R. J.; Jeffries, R. D.; Lewis, J.; Koposov, S. E.; Sacco, G. G.; Randich, S.; Gilmore, G.; Asplund, M.; Binney, J.; Bonifacio, P.; Drew, J. E.; Feltzing, S.; Ferguson, A. M. N.; Micela, G.; Neguerela, I.; Prusti, T.; Rix, H. W.; Vallenari, A.; Alfaro, E. J.; Prieto, C. Allende; Babusiaux, C.; Bensby, T.; Blomme, R.; Bragaglia, A.; Flaccomio, E.; Francois, P.; Hambly, N.; Irwin, M.; Korn, A. J.; Lanzafame, A. C.; Pancino, E.; Recio Blanco, A.; Smiljanic, R.; Van Eck, S.; Walton, N.; Bayo, A.; Bergemann, M.; Carraro, G.; Costado, M. T.; Damiani, F.; Edvardsson, B.; Franciosini, E.; Frasca, A.; Heiter, U.; Hill, V.; Hourihane, A.; Jofre, P.; Lardo, C.; de Laverny, P.; Lind, K.; Magrini, L.; Marconi, G.; Martayan, C.; Masseron, T.; Monaco, L.; Morbidelli, L.; Prisinzano, L.; Sbordone, L.; Sousa, S. G.; Worley, C. C.; Zaggia, S.Context. The Gaia-ESO Survey (GES) is a large public spectroscopic survey at the European Southern Observatory Very Large Telescope.
- ItemThe Gaia-ESO Survey: Galactic evolution of sulphur and zinc(EDP SCIENCES S A, 2017) Duffau, S.; Caffau, E.; Sbordone, L.; Bonifacio, P.; Andrievsky, S.; Korotin, S.; Babusiaux, C.; Salvadori, S.; Monaco, L.; Francois, P.; Skuladottir, A.; Bragaglia, A.; Donati, P.; Spina, L.; Gallagher, A. J.; Ludwig, H. G.; Christlieb, N.; Hansen, C. J.; Mott, A.; Steffen, M.; Zaggia, S.; Blanco Cuaresma, S.; Calura, F.; Friel, E.; Jimenez Esteban, F. M.; Koch, A.; Magrini, L.; Pancino, E.; Tang, B.; Tautvaisiene, G.; Vallenari, A.; Hawkins, K.; Gilmore, G.; Randich, S.; Feltzing, S.; Bensby, T.; Flaccomio, E.; Smiljanic, R.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Damiani, F.; Franciosini, E.; Hourihane, A.; Jofre, P.; Lardo, C.; Lewis, J.; Morbidelli, L.; Sousa, S. G.; Worley, C. C.Context. Due to their volatile nature, when sulphur and zinc are observed in external galaxies, their determined abundances represent the gas-phase abundances in the interstellar medium. This implies that they can be used as tracers of the chemical enrichment of matter in the Universe at high redshift. Comparable observations in stars are more difficult and, until recently, plagued by small number statistics.
- ItemThe Gaia-ESO Survey: radial distribution of abundances in the Galactic disc from open clusters and young-field stars(EDP SCIENCES S A, 2017) Magrini, L.; Randich, S.; Kordopatis, G.; Prantzos, N.; Romano, D.; Ffi, A. Chie; Limongi, M.; Francois, P.; Pancino, E.; Friel, E.; Bragaglia, A.; Tautvaisiene, G.; Spina, L.; Overbeek, J.; Cantat Gaudin, T.; Donati, P.; Vallenari, A.; Sordo, R.; Jimenez Esteban, F. M.; Tang, B.; Drazdauskas, A.; Sousa, S.; Duffau, S.; Jofre, P.; Gilmore, G.; Feltzing, S.; Alfaro, E.; Bensby, T.; Flaccomio, E.; Koposov, S.; Lanzafame, A.; Smiljanic, R.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Damiani, F.; Franciosini, E.; Hourihane, A.; Lardo, C.; Lewis, J.; Monaco, L.; Morbidelli, L.; Sacco, G.; Sbordone, L.; Worley, C. C.; Zaggia, S.Context. The spatial distribution of elemental abundances in the disc of our Galaxy gives insights both on its assembly process and subsequent evolution, and on the stellar nucleogenesis of the different elements. Gradients can be traced using several types of objects as, for instance, (young and old) stars, open clusters, HII regions, planetary nebulae.
- ItemThe Gaia-ESO Survey: revisiting the Li-rich giant problem(OXFORD UNIV PRESS, 2016) Casey, A. R.; Ruchti, G.; Masseron, T.; Randich, S.; Gilmore, G.; Lind, K.; Kennedy, G. M.; Koposov, S. E.; Hourihane, A.; Franciosini, E.; Lewis, J. R.; Magrini, L.; Morbidelli, L.; Sacco, G. G.; Worley, C. C.; Feltzing, S.; Jeffries, R. D.; Vallenari, A.; Bensby, T.; Bragaglia, A.; Flaccomio, E.; Francois, P.; Korn, A. J.; Lanzafame, A.; Pancino, E.; Recio Blanco, A.; Smiljanic, R.; Carraro, G.; Costado, M. T.; Damiani, F.; Donati, P.; Frasca, A.; Jofre, P.; Lardo, C.; de Laverny, P.; Monaco, L.; Prisinzano, L.; Sbordone, L.; Sousa, S. G.; Tautvaisiene, G.; Zaggia, S.; Zwitter, T.; Delgado Mena, E.; Chorniy, Y.; Martell, S. L.; Aguirre, V. Silva; Miglio, A.; Chiappini, C.; Montalban, J.; Morel, T.; Valentini, M.The discovery of lithium-rich giants contradicts expectations from canonical stellar evolution. Here we report on the serendipitous discovery of 20 Li-rich giants observed during the Gaia-ESO Survey, which includes the first nine Li-rich giant stars known towards the CoRoT fields. Most of our Li-rich giants have near-solar metallicities and stellar parameters consistent with being before the luminosity bump. This is difficult to reconcile with deep mixing models proposed to explain lithium enrichment, because these models can only operate at later evolutionary stages: at or past the luminosity bump. In an effort to shed light on the Li-rich phenomenon, we highlight recent evidence of the tidal destruction of close-in hot Jupiters at the sub-giant phase. We note that when coupled with models of planet accretion, the observed destruction of hot Jupiters actually predicts the existence of Li-rich giant stars, and suggests that Li-rich stars should be found early on the giant branch and occur more frequently with increasing metallicity. A comprehensive review of all known Li-rich giant stars reveals that this scenario is consistent with the data. However, more evolved or metal-poor stars are less likely to host close-in giant planets, implying that their Li-rich origin requires an alternative explanation, likely related to mixing scenarios rather than external phenomena.
- ItemThe Gaia-ESO Survey: Sodium and aluminium abundances in giants and dwarfs Implications for stellar and Galactic chemical evolution(EDP SCIENCES S A, 2016) Smiljanic, R.; Romano, D.; Bragaglia, A.; Donati, P.; Magrini, L.; Friel, E.; Jacobson, H.; Randich, S.; Ventura, P.; Lind, K.; Bergemann, M.; Nordlander, T.; Morel, T.; Pancino, E.; Tautvaisiene, G.; Adibekyan, V.; Tosi, M.; Vallenari, A.; Gilmore, G.; Bensby, T.; Francois, P.; Koposov, S.; Lanzafame, A. C.; Recio Blanco, A.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Franciosini, E.; Heiter, U.; Hill, V.; Hourihane, A.; Jofre, P.; Lardo, C.; de Laverny, P.; Lewis, J.; Monaco, L.; Morbidelli, L.; Sacco, G. G.; Sbordone, L.; Sousa, S. G.; Worley, C. C.; Zaggia, S.Context. Stellar evolution models predict that internal mixing should cause some sodium overabundance at the surface of red giants more massive than similar to 1.5-2.0 M-circle dot. The surface aluminium abundance should not be affected. Nevertheless, observational results disagree about the presence and/or the degree of Na and Al overabundances. In addition, Galactic chemical evolution models adopting different stellar yields lead to very different predictions for the behavior of [Na/Fe] and [Al/Fe] versus [Fe/H]. Overall, the observed trends of these abundances with metallicity are not well reproduced.
- ItemThe Gaia-ESO Survey: the selection function of the Milky Way field stars(OXFORD UNIV PRESS, 2016) Stonkute, E.; Koposov, S. E.; Howes, L. M.; Feltzing, S.; Worley, C. C.; Gilmore, G.; Ruchti, G. R.; Kordopatis, G.; Randich, S.; Zwitter, T.; Bensby, T.; Bragaglia, A.; Smiljanic, R.; Costado, M. T.; Tautvaisiene, G.; Casey, A. R.; Korn, A. J.; Lanzafame, A. C.; Pancino, E.; Franciosini, E.; Hourihane, A.; Jofre, P.; Lardo, C.; Lewis, J.; Magrini, L.; Monaco, L.; Morbidelli, L.; Sacco, G. G.; Sbordone, L.The Gaia-ESO Survey was designed to target all major Galactic components (i.e. bulge, thin and thick discs, halo and clusters), with the goal of constraining the chemical and dynamical evolution of the Milky Way. This paper presents the methodology and considerations that drive the selection of the targeted, allocated and successfully observed Milky Way field stars. The detailed understanding of the survey construction, specifically the influence of target selection criteria on observed Milky Way field stars is required in order to analyse and interpret the survey data correctly. We present the target selection process for the Milky Way field stars observed with Very Large Telescope/Fibre Large Array Multi Element Spectrograph and provide the weights that characterize the survey target selection. The weights can be used to account for the selection effects in the Gaia-ESO Survey data for scientific studies. We provide a couple of simple examples to highlight the necessity of including such information in studies of the stellar populations in the Milky Way.
- ItemThe VVV Survey of the Milky Way: first year results(2011) Minniti, D.; Clariá, J. J.; Saito, R. K.; Hempel, M.; Lucas, P. W.; Rejkuba, M.; Toledo, I.; Gonzalez, O. A.; Alonso-García, J.; Irwin, M. J.; Gonzalez-Solares, E.; Cross, N.; Ivanov, V. D.; Soto, M.; Dékány, I.; Angeloni, R.; Catelan, Marcio; Amôres, E. B.; Gurovich, S.; Emerson, J. P.; Lewis, J.; Hodgkin, S.; Pietrukowicz, P.; Zoccali, M.; Sale, S. E.; Barbá, R.; Barbuy, B.; Beamin, J. C.; Helminiak, K.; Borissova, J.; Folkes, S. L.; Gamen, R. C.; Geisler, D.; Mauro, F.; Chené, A. -N.; Alonso, M. V.; Gunthardt, G.; Hanson, M.; Kerins, E.; Kurtev, R.; Majaess, D.; Martín, E.; Masetti, N.; Mirabel, I. F.; Monaco, L.; Moni Bidin, C.; Padilla, N.; Rojas, A.; Pietrzynski, G.; Saviane, I.; Valenti, E.; Weidmann, W.; López-Corredoira, M.; Ahumada, A. V.; Aigrain, S.; Arias, J. I.; Bica, E.; Bandyopadhyay, R. M.; Baume, G.; Bedin, L. R.; Bonatto, C.; Bronfman, L.; Carraro, G.; Contreras, C.; Davis, C. J.; de Grijs, R.; Dias, B.; Drew, J. E.; Fariña, C.; Feinstein, C.; Fernández Lajús, E.; Gieren, W.; Goldman, B.; Gosling, A.; Hambly, N. C.; Hoare, M.; Jordán, A.; Kinemuchi, K.; Maccarone, T.; Merlo, D. C.; Mennickent, R. E.; Morelli, L.; Motta, V.; Palma, T.; Popescu, B.; Parisi, M. C.; Parker, Q.; Pignata, G.; Read, M. A.; Ruiz, M. T.; Roman-Lopes, A.; Schreiber, M. R.; Schröder, A. C.; Smith, M.; Sodré, L., Jr.; Stephens, A. W.; Walton, N. A.; Zijlstra, A. A.; Tamura, M.; Tappert, C.; Thompson, M. A.; Vanzi, L.The VISTA Variables in the Via Lactea (VVV) is an ESO public near-IR variability survey that is scanning the Milky Way bulge and an adjacent section of the Galactic mid-plane. The survey will take 1929 hours of observations with the VISTA 4.1-m telescope during five years, covering a billion point sources across an area of 520 sqdeg, including 36 known globular clusters and more than 350 open clusters. The final product will be a deep IR atlas in five passbands (0.9 - 2.5 microns) and a catalogue of more than a million variable point sources....
- ItemThe VVV Survey: New Results (Part I)(2014) Minniti, D.; Saito, R. K.; Hempel, M.; Lucas, P. W.; Rejkuba, M.; Toledo, I.; Gonzalez, O. A.; Alonso-García, J.; Irwin, M. J.; Gonzalez-Solares, E.; Hodgkin, S. T.; Lewis, J. R.; Cross, N.; Ivanov, V. D.; Kerins, E.; Emerson, J. P.; Soto, M.; Amôres, E. B.; Gurovich, S.; Dékány, I.; Angeloni, R.; Beamin, J. C.; Catelan, Marcio; Padilla, N.; Zoccali, M.; Pietrukowicz, P.; Moni Bidin, C.; Mauro, F.; Geisler, D.; Folkes, S. L.; Sale, S. E.; Borissova, J.; Kurtev, R.; Ahumada, A. V.; Alonso, M. V.; Adamson, A.; Arias, J. I.; Bandyopadhyay, R. M.; Barbá, R. H.; Barbuy, B.; Baume, G. L.; Bedin, L. R.; Benjamin, R.; Bica, E.; Bonatto, C.; Bronfman, L.; Carraro, G.; Chenè, A. N.; Clariá, J. J.; Clarke, J. R. A.; Contreras, C.; Corvillón, A.; de Grijs, R.; Dias, B.; Drew, J. E.; Fariía, C.; Feinstein, C.; Fernández-Lajús, E.; Gamen, R. C.; Gieren, W.; Goldman, B.; González-Fernández, C.; Grand, R. J. J.; Gunthardt, G.; Hambly, N. C.; Hanson, M. M.; Helminiak, K.; Hoare, M. G.; Huckvale, L.; Jordán, A.; Kinemuchi, K.; Longmore, A.; López-Corredoira, M.; Maccarone, T.; Majaess, D.; Martín, E.; Masetti, N.; Mennickent, R. E.; Mirabel, I. F.; Monaco, L.; Morelli, L.; Motta, V.; Palma, T.; Parisi, M. C.; Parker, Q.; Peñaloza, F.; Pietrzyński, G.; Pignata, G.; Popescu, B.; Read, M. A.; Rojas, A.; Roman-Lopes, A.; Ruiz, M. T.; Saviane, I.; Schreiber, M. R.; Schröder, A. C.; Sharma, S.; Smith, M. D.; Sodré, L.; Stead, J.; Stephens, A. W.; Tamura, M.; Tappert, C.; Thompson, M. A.; Valenti, E.; Vanzi, L.; Walton, N. A.; Weidmann, W.; Zijlstra, A.
- ItemThe VVV Survey: New Results (Part II)(2014) Minniti, D.; Saito, R. K.; Hempel, M.; Lucas, P. W.; Rejkuba, M.; Toledo, I.; Gonzalez, O. A.; Alonso-García, J.; Irwin, M. J.; Gonzalez-Solares, E.; Hodgkin, S. T.; Lewis, J. R.; Cross, N.; Ivanov, V. D.; Kerins, E.; Emerson, J. P.; Soto, M.; Amôres, E. B.; Gurovich, S.; Dékány, I.; Angeloni, R.; Beamin, J. C.; Catelan, Marcio; Padilla, N.; Zoccali, M.; Pietrukowicz, P.; Moni Bidin, C.; Mauro, F.; Geisler, D.; Folkes, S. L.; Sale, S. E.; Borissova, J.; Kurtev, R.; Ahumada, A. V.; Alonso, M. V.; Adamson, A.; Arias, J. I.; Bandyopadhyay, R. M.; Barbá, R. H.; Barbuy, B.; Baume, G. L.; Bedin, L. R.; Benjamin, R.; Bica, E.; Bonatto, C.; Bronfman, L.; Carraro, G.; Chenè, A. N.; Clariá, J. J.; Clarke, J. R. A.; Contreras, C.; Corvillón, A.; de Grijs, R.; Dias, B.; Drew, J. E.; Fariña, C.; Feinstein, C.; Fernández-Lajús, E.; Gamen, R. C.; Gieren, W.; Goldman, B.; González-Fernández, C.; Grand, R. J. J.; Gunthardt, G.; Hambly, N. C.; Hanson, M. M.; Helminiak, K.; Hoare, M. G.; Huckvale, L.; Jordán, A.; Kinemuchi, K.; Longmore, A.; López-Corredoira, M.; Maccarone, T.; Majaess, D.; Martín, E.; Masetti, N.; Mennickent, R. E.; Mirabel, I. F.; Monaco, L.; Morelli, L.; Motta, V.; Palma, T.; Parisi, M. C.; Parker, Q.; Peñaloza, F.; Pietrzyński, G.; Pignata, G.; Popescu, B.; Read, M. A.; Rojas, A.; Roman-Lopes, A.; Ruiz, M. T.; Saviane, I.; Schreiber, M. R.; Schröder, A. C.; Sharma, S.; Smith, M. D.; Sodré, L.; Stead, J.; Stephens, A. W.; Tamura, M.; Tappert, C.; Thompson, M. A.; Valenti, E.; Vanzi, L.; Walton, N. A.; Weidmann, W.; Zijlstra, A.
- ItemTOPoS II. On the bimodality of carbon abundance in CEMP stars Implications on the early chemical evolution of galaxies(EDP SCIENCES S A, 2015) Bonifacio, P.; Caffau, E.; Spite, M.; Limongi, M.; Chieffi, A.; Klessen, R. S.; Francois, P.; Molaro, P.; Ludwig, H. G.; Zaggia, S.; Spite, F.; Plez, B.; Cayrel, R.; Christlieb, N.; Clark, P. C.; Glover, S. C. O.; Hammer, F.; Koch, A.; Monaco, L.; Sbordone, L.; Steffen, M.Context. In the course of the Turn Off Primordial Stars (TOPoS) survey, aimed at discovering the lowest metallicity stars, we have found several carbon-enhanced metal-poor (CEMP) stars. These stars are very common among the stars of extremely low metallicity and provide important clues to the star formation processes. We here present our analysis of six CEMP stars.
- ItemVISTA Milky Way Public Survey(2009) Minniti, D.; Lucas, P.; Ahumada, A. V.; Zoccali, M.; Catelan, Marcio; Morelli, L.; Tappert, C.; Pignata, G.; Toledo, I.; Ruiz, M. T.; Carraro, G.; Casassus, S.; Bronfman, L.; Barbá, R. H.; Gamen, R.; Gieren, W.; Geisler, D.; Pietrzynski, G.; Mennickent, R. E.; Kurtev, R.; Borissova, J.; Mirabel, F.; Ivanov, V. D.; Saviane, I.; Vanzi, L.; Monaco, L.; Rejkuba, M.; Messineo, M.; Bedin, L.; Stephens, A.; Barbuy, B.; Bica, E.; Clariá, J. J.; CASU (VDFS) Team; WFAU (VDFS) Team; Emerson, J.; Drew, J.; López-Correidora, M.; Martin, E.; Goldman, B.; Gianinni, T.; Eisloeffel, J.; Groot, P.; Fabregat, J.; Hambly, N.; Longmore, A.; Walton, N.; de Grijs, R.; Hoare, M.; Schroeder, A.; Naylor, T.; Barlow, M.; Zijlstra, A.; White, G.; Gosling, A.; McGowan, K.; Adamson, A.; Bandyopadhyay, R.; Thompson, M.; Cropper, M.; Lucey, J.; Kerins, E.; Hodgkin, S.; Pinfield, D.We propose a public IR variability survey, named ``Vista Variables in the Vía Láctea'' (VVV), of the Milky Way bulge and an adjacent section of the mid-plane where star formation activity is high. This would take 1920 hours, covering ∼ 10^9 point sources within an area of 520 sq deg, including 33 known globular clusters and ∼ 350 open clusters. The final products will be a deep IR atlas in 5 passbands and a catalogue of ∼ 10^6 variable point sources. These will produce a 3-D map of the surveyed region (unlike single-epoch surveys that only give 2-D maps) using well-understood primary distance indicators such as RR Lyrae stars. It will yield important information on the ages of the populations. The observations will be combined with data from MACHO, OGLE, EROS, VST, SPITZER, HST, CHANDRA, INTEGRAL, and ALMA for a complete understanding of the variable sources in the inner Milky Way. Several important implications for the history of the Milky Way, for globular cluster evolution, for the population census of the bulge and center, and for pulsation theory would follow from this survey....
- ItemVISTA Variables in the Via Lactea (VVV): Current Status and First Results(2010) Saito, R.; Hempel, M.; Alonso-García, J.; Toledo, I.; Borissova, J.; González, O.; Beamin, J. C.; Minniti, D.; Lucas, P.; Emerson, J.; Ahumada, A.; Aigrain, S.; Alonso, M. V.; Amôres, E.; Angeloni, R.; Arias, J.; Bandyopadhyay, R.; Barbá, R.; Barbuy, B.; Baume, G.; Bedin, L.; Bica, E.; Bronfman, L.; Carraro, G.; Catelan, Marcio; Clariá, J.; Contreras, C.; Cross, N.; Davis, C.; de Grijs, R.; Dékány, I.; Janet Drew, J. D.; Fariña, C.; Feinstein, C.; Fernández Lajús, E.; Folkes, S.; Gamen, R.; Geisler, D.; Gieren, W.; Goldman, B.; Gosling, A.; Gunthardt, G.; Gurovich, S.; Hambly, N.; Hanson, M.; Hoare, M.; Irwin, M.; Ivanov, V.; Jordán, A.; Kerins, E.; Kinemuchi, K.; Kurtev, R.; Longmore, A.; López-Corredoira, M.; Maccarone, T.; Martín, E.; Masetti, N.; Mennickent, R.; Merlo, D.; Messineo, M.; Mirabel, F.; Monaco, L.; Moni Bidin, C.; Morelli, L.; Padilla, N.; Palma, T.; Parisi, M. C.; Parker, Q.; Pavani, D.; Pietrukowicz, P.; Pietrzynski, G.; Pignata, G.; Rejkuba, M.; Rojas, A.; Roman Lopes, A.; Ruiz, M. T.; Sale, S.; Saviane, I.; Schreiber, M.; Schröder, A.; Sharma, S.; Smith, M.; Sodré, L., Jr.; Soto, M.; Stephens, A.; Tamura, M.; Tappert, C.; Thompson, M.; Valenti, E.; Vanzi, L.; Weidmann, W.; Zoccali, M.VISTA Variables in the Vía Láctea (VVV) is a public ESO near-IR variability survey aimed at scanning the Milky Way Bulge and an adjacent section of the mid-plane. VVV observations started in October 2009 during ESO science verification. Regular observations for the first year of the survey have been conducted since February 2010 and will cover a total area of 520 square degrees in five passbands and five epochs. Here we address the first results obtained from the VVV Survey as well as the current status of the observations....
- ItemVISTA Variables in the Vía Láctea (VVV): Halfway Status and Results(2014) Hempel, M.; Minniti, D.; Dékány, I.; Saito, R. K.; Lucas, P. W.; Emerson, J. P.; Ahumada, A. V.; Aigrain, S.; Alonso, M. V.; Alonso-García, J.; Amôres, E. B.; Angeloni, R.; Arias, J.; Bandyopadhyay, R.; Barbá, R. H.; Barbuy, B.; Baume, G.; Beamin, J. C.; Bedin, L.; Bica, E.; Borissova, J.; Bronfman, L.; Carraro, G.; Catelan, Marcio; Clariá, J. J.; Contreras, C.; Cross, N.; Davis, C.; de Grijs, R.; Drew, J. E.; Fariña, C.; Feinstein, C.; Fernández-Lajús, E. F.; Folkes, S.; Gamen, R. C.; Geisler, D.; Gieren, W.; Goldman, B.; González, O.; Gosling, A.; Gunthardt, G.; Gurovich, S.; Hambly, N. C.; Hanson, M.; Hoare, M.; Irwin, M. J.; Ivanov, V. D.; Jordán, A.; Kerins, E.; Kinemuchi, K.; Kurtev, R.; Longmore, A.; López-Corredoira, M.; Maccarone, T.; Martín, E.; Masetti, N.; Mennickent, R. E.; Merlo, D.; Messineo, M.; Mirabel, I. F.; Monaco, L.; Moni-Bidin, C.; Morelli, L.; Padilla, N.; Palma, T.; Parisi, M. C.; Parker, Q.; Pavani, D.; Pietrukowicz, P.; Pietrzynski, G.; Pignata, G.; Rejkuba, M.; Rojas, A.; Roman-Lopes, A.; Ruiz, M. T.; Sale, S. E.; Saviane, I.; Schreiber, M. R.; Schröder, A. C.; Sharma, S.; Smith, M.; Sodré, L., Jr.; Soto, M.; Stephens, A. W.; Tamura, M.; Tappert, C.; Thompson, M. A.; Toledo, I.; Valenti, E.; Vanzi, L.; Weidmann, W.; Zoccali, M.The VISTA Variables in the Vía Láctea (VVV) survey is one of six near-infrared ESO public surveys, and is now in its fourth year of observing. Although far from being complete, the VVV survey has already delivered many results, some directly connected to the intended science goals (detection of variable stars, microlensing events, new star clusters), others concerning more exotic objects, e.g., novae. Now, at the end of the fourth observing period, and comprising roughly 50% of the proposed observations, the status of the survey, as well some of results based on the VVV data, are presented....
- ItemVISTA Variables in the Via Lactea (VVV): The public ESO near-IR variability survey of the Milky Way(ELSEVIER, 2010) Minniti, D.; Lucas, P. W.; Emerson, J. P.; Saito, R. K.; Hempel, M.; Pietrukowicz, P.; Ahumada, A. V.; Alonso, M. V.; Alonso Garcia, J.; Arias, J. I.; Bandyopadhyay, R. M.; Barba, R. H.; Barbuy, B.; Bedin, L. R.; Bica, E.; Borissova, J.; Bronfman, L.; Carraro, G.; Catelan, M.; Claria, J. J.; Cross, N.; de Grijs, R.; Dekany, I.; Drew, J. E.; Farina, C.; Feinstein, C.; Fernandez Lajus, E.; Gamen, R. C.; Geisler, D.; Gieren, W.; Goldman, B.; Gonzalez, O. A.; Gunthardt, G.; Gurovich, S.; Hambly, N. C.; Irwin, M. J.; Ivanov, V. D.; Jordan, A.; Kerins, E.; Kinemuchi, K.; Kurtev, R.; Lopez Corredoira, M.; Maccarone, T.; Masetti, N.; Merlo, D.; Messineo, M.; Mirabel, I. F.; Monaco, L.; Morelli, L.; Padilla, N.; Palma, T.; Parisi, M. C.; Pignata, G.; Rejkuba, M.; Roman Lopes, A.; Sale, S. E.; Schreiber, M. R.; Schroeder, A. C.; Smith, M.; Sodre, L., Jr.; Soto, M.; Tamura, M.; Tappert, C.; Thompson, M. A.; Toledo, I.; Zoccali, M.; Pietrzynski, G.We describe the public ESO near-IR variability survey (VVV) scanning the Milky Way bulge and an adjacent section of the mid-plane where star formation activity is high. The survey will take 1929 h of observations with the 4-m VISTA telescope during 5 years (2010-2014), covering similar to 10(9) point sources across an area of 520 deg(2), including 33 known globular clusters and similar to 350 open clusters. The final product will be a deep near-IR atlas in five passbands (0.9-2.5 mu m) and a catalogue of more than 106 variable point sources. Unlike single-epoch surveys that, in most cases, only produce 2-D maps, the VVV variable star survey will enable the construction of a 3-D map of the surveyed region using well-understood distance indicators such as RR Lyrae stars, and Cepheids. It will yield important information on the ages of the populations. The observations will be combined with data from MACHO, OGLE, EROS, VST, Spitzer, HST, Chandra, INTEGRAL, WISE, Fermi LAT, XMM-Newton, GAIA and ALMA for a complete understanding of the variable sources in the inner Milky Way. This public survey will provide data available to the whole community and therefore will enable further studies of the history of the Milky Way, its globular cluster evolution, and the population census of the Galactic Bulge and center, as well as the investigations of the star forming regions in the disk. The combined variable star catalogues will have important implications for theoretical investigations of pulsation properties of stars. (C) 2009 Elsevier B.V. All rights reserved.