17 results on '"Wyse R.F.G."'
Search Results
2. M 31, M 33 AND THE MILKY WAY: SIMILARITIES AND DIFFERENCES
- Author
-
Wyse, R.F.G., primary
- Published
- 2020
- Full Text
- View/download PDF
3. Chemical Abundances and Milky Way Formation
- Author
-
Gilmore, G., Wyse, R.F.G., Leibundgut, Bruno, editor, Randich, Sofia, editor, and Pasquini, Luca, editor
- Published
- 2006
- Full Text
- View/download PDF
4. Chemical Evolution in the Carina Dwarf 1Spheroidal
- Author
-
Koch, A., Grebel, E.K., Harbeck, D., Wilkinson, M.I., Kleyna, J.T., Gilmore, G.F., Wyse, R.F.G., Evans, N.W., Leibundgut, Bruno, editor, Randich, Sofia, editor, and Pasquini, Luca, editor
- Published
- 2006
- Full Text
- View/download PDF
5. Observed Properties of Dark Matter: dynamical studies of dSph galaxies
- Author
-
Gilmore, G., Wilkinson, M., Kleyna, J., Koch, A., Evans, Wyn, Wyse, R.F.G., and Grebel, E.K.
- Published
- 2007
- Full Text
- View/download PDF
6. Where Do We Stand?
- Author
-
Wyse, R.F.G., primary
- Published
- 2000
- Full Text
- View/download PDF
7. Chemical Evolution in the Carina Dwarf 1Spheroidal
- Author
-
Koch, A., primary, Grebel, E.K., additional, Harbeck, D., additional, Wilkinson, M.I., additional, Kleyna, J.T., additional, Gilmore, G.F., additional, Wyse, R.F.G., additional, and Evans, N.W., additional
- Full Text
- View/download PDF
8. Chemical Abundances and Milky Way Formation
- Author
-
Gilmore, G., primary and Wyse, R.F.G., additional
- Full Text
- View/download PDF
9. Automated stellar spectra parameterisation for Gaia-RVS
- Author
-
Kordopatis, G., primary, Recio-Blanco, A., additional, de Laverny, P., additional, Bijaoui, A., additional, Hill, V., additional, Gilmore, G., additional, Wyse, R.F.G., additional, and Ordenovic, C., additional
- Published
- 2012
- Full Text
- View/download PDF
10. Metallicity and kinematical clues to the formation of the Local Group
- Author
-
Wyse, R.F.G., primary
- Published
- 2010
- Full Text
- View/download PDF
11. A spectroscopic survey of the Thick Disc outside the Solar neighbourhood: A comparison with the Besançon model
- Author
-
Kordopatis, G., primary, Recio-Blanco, A., additional, de Laverny, P., additional, Gilmore, G., additional, Hill, V., additional, Wyse, R.F.G., additional, Helmi, A., additional, Bijaoui, A., additional, Ordenovic, C., additional, Zoccali, M., additional, and Bienaymé, O., additional
- Published
- 2010
- Full Text
- View/download PDF
12. M 31, M 33 and the Milky Way: Similarities and Differences
- Author
-
Wyse, R.F.G. and Wyse, R.F.G.
- Abstract
The large galaxies in the Local Group, as all disk galaxies, have diverse stellar populations. A better understanding of these differences, and a physical understanding of the causes, requires more detailed study of the older populations. This presents a significant challenge to GAIA but the scientific returns are also significant.
- Published
- 2002
- Full Text
- View/download PDF
13. The formation of the Hubble sequence of disc galaxies: the effects of early viscous evolution.
- Author
-
Zhang, B. and Wyse, R.F.G.
- Subjects
- *
GALAXY formation , *GALACTIC bulges - Abstract
We investigate a model of disc galaxies whereby viscous evolution of the gaseous disc drives material inwards to form a protobulge. We start from the standard picture of disc formation through the settling of gas into a dark halo potential well, with the disc initially coming into centrifugal equilibrium with detailed conservation of angular momentum. We derive generic analytic solutions for the disc–halo system after adiabatic compression of the dark halo, with free choice of the input virialized dark halo density profile and of the specific angular momentum distribution. We derive limits on the final density profile of the halo in the central regions. Subsequent viscous evolution of the disc is modelled by a variation of the specific angular momentum distribution of the disc, providing analytic solutions to the final disc structure. The assumption that the viscous evolution time-scale and the star formation time-scale are similar leads to predictions of the properties of the stellar components. Focusing on small ‘exponential’ bulges, i.e., ones that may be formed through a disc instability, we investigate the relationship between the assumed initial conditions, such as halo ‘formation’, or assembly, redshift z[sub f], spin parameter λ, baryonic fraction F, and final disc properties such as global star formation time-scale, gas fraction, and bulge-to-disc ratio. We find that the present properties of discs, such as the scalelength, are compatible with a higher initial formation redshift if the redistribution by viscous evolution is included than if it is ignored. We also quantify the dependence of final disc properties on the ratio Fλ, thus including the possibility that the baryonic fraction varies from galaxy to galaxy, as perhaps may be inferred from the observations. [ABSTRACT FROM AUTHOR]
- Published
- 2000
- Full Text
- View/download PDF
14. The relationship between the optical Hα filaments and the X-ray emission in the core of the Perseus cluster.
- Author
-
Fabian, A.C., Sanders, J.S., Crawford, C.S., Conselice, C.J., Gallagher III, J.S., and Wyse, R.F.G.
- Subjects
GALAXY clusters ,X-ray spectroscopy - Abstract
ABSTRACT NGC 1275 in the centre of the Perseus cluster of galaxies, Abell 426, is surrounded by a spectacular filamentary Hα nebula. Deep Chandra X-ray imaging has revealed that the brighter outer filaments are also detected in soft X-rays. This can be due to conduction and mixing of the cold gas in the filaments with the hot, dense intracluster medium. We show the correspondence of the filaments in both wavebands and draw attention to the relationship of two prominent curved north-west filaments to an outer, buoyant radio bubble seen as a hole in the X-ray image. There is a strong resemblance in the shape of the hole and the disposition of the filaments to the behaviour of a large air bubble rising in water. If this is a correct analogy, then the flow is laminar and the intracluster gas around this radio source is not turbulent. We obtain a limit on the viscosity of this gas. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
15. The Sixth Data Release of the Radial Velocity Experiment (R ave). II. Stellar Atmospheric Parameters, Chemical Abundances, and Distances
- Author
-
Savita Mathur, Quentin A. Parker, Diego Bossini, I. Carrillo, Amina Helmi, Cristina Chiappini, Luca Casagrande, Marica Valentini, Paul J. McMillan, Teresa Antoja, Brad K. Gibson, Sanjib Sharma, Kenneth C. Freeman, Benoit Famaey, Andrea Miglio, Harry Enke, Joss Bland-Hawthorn, Rosemary F. G. Wyse, G. R. Ruchti, Georges Kordopatis, George M. Seabroke, Benoit Mosser, Gal Matijevic, Julio F. Navarro, M. Stupar, Fred Watson, Alessandro Siviero, Mary E K Williams, J. P. Fulbright, Gerard Gilmore, Kseniia Sysoliatina, Giacomo Monari, Tomaž Zwitter, Paul Cass, Danijela Birko, Friedrich Anders, Yvonne Elsworth, Eva K. Grebel, Warren A. Reid, Ulisse Munari, Kristin Fiegert, Olivier Bienaymé, Andreas Ritter, Alejandra Recio-Blanco, James Binney, Thaíse S. Rodrigues, Guillaume Guiglion, Arnaud Siebert, Ralf-Dieter Scholz, Patrick de Laverny, Paula Jofre, Andreas Just, D. Burton, Ortwin Gerhard, Jennifer Wojno, Ivan Minchev, William J. Chaplin, Albert Bijaoui, Andrea Kunder, Borja Anguiano, Rafael A. García, Matthias Steinmetz, Leibniz Institute for Astrophysics Potsdam, Australian Astronomical Observatory, Australian National University, Australian Research Council, Agence Nationale de la Recherche (France), German Research Foundation, European Research Council, Istituto Nazionale di Astrofisica, Johns Hopkins University, National Science Foundation (US), W. M. Keck Foundation, Macquarie University, Netherlands Research School for Astronomy, Natural Sciences and Engineering Research Council of Canada, Slovenian Research Agency, Swiss National Science Foundation, Science and Technology Facilities Council (UK), Opticon, Observatoire Astronomique de Strasbourg, University of Basel, University of Groningen, University of Heidelberg, University of Sydney, Centre National D'Etudes Spatiales (France), Ministerio de Economía y Competitividad (España), Kavli Institute for Theoretical Physics, Simons Foundation, Steinmetz M., Guiglion G., McMillan P.J., Matijevic G., Enke H., Kordopatis G., Zwitter T., Valentini M., Chiappini C., Casagrande L., Wojno J., Anguiano B., Bienayme O., Bijaoui A., Binney J., Burton D., Cass P., De Laverny P., Fiegert K., Freeman K., Fulbright J.P., Gibson B.K., Gilmore G., Grebel E.K., Helmi A., Kunder A., Munari U., Navarro J.F., Parker Q., Ruchti G.R., Recio-Blanco A., Reid W., Seabroke G.M., Siviero A., Siebert A., Stupar M., Watson F., Williams M.E.K., Wyse R.F.G., Anders F., Antoja T., Birko D., Bland-Hawthorn J., Bossini D., Garcia R.A., Carrillo I., Chaplin W.J., Elsworth Y., Famaey B., Gerhard O., Jofre P., Just A., Mathur S., Miglio A., Minchev I., Monari G., Mosser B., Ritter A., Rodrigues T.S., Scholz R.-D., Sharma S., Sysoliatina K., Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Astronomy
- Subjects
010504 meteorology & atmospheric sciences ,ACCURACY ,FOS: Physical sciences ,Library science ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,surveys ,Observatory ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,KINEMATICS ,Abundances ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Physics ,F-DWARF ,European research ,Surveys - Stars ,Astronomy and Astrophysics ,DISC ,Astrophysics - Astrophysics of Galaxies ,Distances ,Astrophysics - Solar and Stellar Astrophysics ,stars: abundances - distances ,13. Climate action ,Space and Planetary Science ,Research council ,Astrophysics of Galaxies (astro-ph.GA) ,PATTERN SPEED ,MILKY ,Christian ministry ,[SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA] ,Astrophysics::Earth and Planetary Astrophysics ,EXPERIMENT RAVE ,SKY SURVEY ,Data release ,STARS ,ISOCHRONES - Abstract
We present part 2 of the sixth and final Data Release (DR6) of the Radial Velocity Experiment (Rave), a magnitude-limited spectroscopic survey of Galactic stars randomly selected in Earth's southern hemisphere. The Rave medium-resolution spectra (R ∼ 7500) cover the Ca triplet region (8410-8795 Å) and span the complete time frame from the start of Rave observations on 2003 April 12 to their completion on 2013 April 4. In the second of two publications, we present the data products derived from 518,387 observations of 451,783 unique stars using a suite of advanced reduction pipelines focusing on stellar atmospheric parameters, in particular purely spectroscopically derived stellar atmospheric parameters, and the overall metallicity), enhanced stellar atmospheric parameters inferred via a Bayesian pipeline using Gaia DR2 astrometric priors, and asteroseismically calibrated stellar atmospheric parameters for giant stars based on asteroseismic observations for 699 K2 stars. In addition, we provide abundances of the elements Fe, Al, and Ni, as well as an overall [α/Fe] ratio obtained using a new pipeline based on the GAUGUIN optimization method that is able to deal with variable signal-to-noise ratios. The Rave DR6 catalogs are cross-matched with relevant astrometric and photometric catalogs, and are complemented by orbital parameters and effective temperatures based on the infrared flux method. The data can be accessed via the Rave website (http://rave-survey.org) or the Vizier database., Funding for Rave has been provided by: the Leibniz-Institut f¨ur Astrophysik Potsdam (AIP); the Australian Astronomical Observatory; the Australian National University; the Australian Research Council; the French National Research Agency (Programme National Cosmology et Galaxies (PNCG) of CNRS/INSU with INP and IN2P3, co-funded by CEA and CNES); the German Research Foundation (SPP 1177 and SFB 881); the European Research Council (ERC-StG 240271 Galactica); the Istituto Nazionale di Astrofisica at Padova; The Johns Hopkins University; the National Science Foundation of the USA (AST-0908326); the W. M. Keck foundation; the Macquarie University; the Netherlands Research School for Astronomy; the Natural Sciences and Engineering Research Council of Canada; the Slovenian Research Agency (research core funding no. P1-0188); the Swiss National Science Foundation; the Science & Technology Facilities Council of the UK; Opticon; Strasbourg Observatory; and the Universities of Basel, Groningen, Heidelberg, and Sydney. PJM is supported by grant 2017-03721 from the Swedish Research Council. LC is the recipient of the ARC Future Fellowship FT160100402. RAG acknowledges the support from the PLATO CNES grant. SM would like to acknowledge support from the Spanish Ministry with the Ramon y Cajal fellowship number RYC-2015-17697. MS thanks the Research School of Astronomy & Astrophysics in Canberra for support through a Distinguished Visitor Fellowship. RFGW thanks the Kavli Institute for Theoretical Physics and the Simons Foundation for support as a Simons Distinguished Visiting Scholar. This research was supported in part by the National Science Foundation under Grant No. NSF PHY-1748958 to KITP.
- Published
- 2020
16. The Gaia-ESO Survey: New constraints on the Galactic disc velocity dispersion and its chemical dependencies
- Author
-
Jack Lewis, A. Hourihane, Sofia Randich, Karin Lind, Paula Jofre, Ivan Minchev, E. Franciosini, S. Mikolaitis, Gerard Gilmore, R. F. G. Wyse, Laura Magrini, M. T. Costado, G. G. Sacco, L. Morbidelli, Gregory R. Ruchti, Vanessa Hill, Cristina Chiappini, P. de Laverny, Clare Worley, Alejandra Recio-Blanco, Elena Pancino, Carmela Lardo, Sofia Feltzing, Thomas Bensby, Georges Kordopatis, Ettore Flaccomio, Guillaume Guiglion, Simone Zaggia, Amelia Bayo, Sergey E. Koposov, Guiglion G., Recio-Blanco A., De Laverny P., Kordopatis G., Hill V., Mikolaitis S., Minchev I., Chiappini C., Wyse R.F.G., Gilmore G., Randich S., Feltzing S., Bensby T., Flaccomio E., Koposov S.E., Pancino E., Bayo A., Costado M.T., Franciosini E., Hourihane A., Jofre P., Lardo C., Lewis J., Lind K., Magrini L., Morbidelli L., Sacco G.G., Ruchti G., Worley C.C., and Zaggia S.
- Subjects
010504 meteorology & atmospheric sciences ,Metallicity ,Milky Way ,astro-ph.GA ,FOS: Physical sciences ,Kinematics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Galaxy: disk ,Astronomi, astrofysik och kosmologi ,0103 physical sciences ,stellar content [Galaxy] ,Astronomy, Astrophysics and Cosmology ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Spectrograph ,QC ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,QB ,Physics ,Galaxy: stellar content ,Turbulence ,Stars: abundances ,Velocity dispersion ,abundances [Galaxy] ,Astronomy and Astrophysics ,kinematics and dynamics [Galaxy] ,Astrophysics - Astrophysics of Galaxies ,abundances [stars] ,Galaxy: abundance ,Stars ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Galaxy: kinematics and dynamic ,Astrophysics::Earth and Planetary Astrophysics ,Data release ,disk [Galaxy] - Abstract
Understanding the history and the evolution of the Milky Way disc is one of the main goals of modern astrophysics. We study the velocity dispersion behaviour of Galactic disc stars as a function of the [Mg/Fe] ratio, which can be used as a proxy of relative age. This key relation is essential to constrain the formation mechanisms of the disc stellar populations as well as the cooling processes. We used the recommended parameters and chemical abundances of 7800 FGK Milky Way field stars from the second internal data release of the Gaia-ESO Survey. These stars were observed with the GIRAFFE spectrograph, and cover a large spatial volume (6+0.2dex. First, the velocity dispersion increases with [Mg/Fe] at all [Fe/H] ratios for the thin-disc stars, and then it decreases for the thick-disc at the highest [Mg/Fe] abundances. Similar trends are observed within the errors for the azimuthal velocity dispersion, while a continuous increase with [Mg/Fe] is observed for the vertical velocity dispersion. The velocity dispersion decrease agrees with previous measurements of the RAVE survey, although it is observed here for a greater metallicity interval and a larger spatial volume. We confirm the existence of [Mg/Fe]-rich thick-disc stars with cool kinematics in the generally turbulent context of the primitive Galactic disc. This is discussed in the framework of the different disc formation scenarios., Comment: 14 pages, 13 figures, A&A accepted
- Published
- 2015
17. TheGaia-ESO Survey: characterisation of the [α/Fe] sequences in the Milky Way discs
- Author
-
G. Kordopatis, R. F. G. Wyse, G. Gilmore, A. Recio-Blanco, P. de Laverny, V. Hill, V. Adibekyan, U. Heiter, I. Minchev, B. Famaey, T. Bensby, S. Feltzing, G. Guiglion, A. J. Korn, Š. Mikolaitis, M. Schultheis, A. Vallenari, A. Bayo, G. Carraro, E. Flaccomio, E. Franciosini, A. Hourihane, P. Jofré, S. E. Koposov, C. Lardo, J. Lewis, K. Lind, L. Magrini, L. Morbidelli, E. Pancino, S. Randich, G. G. Sacco, C. C. Worley, S. Zaggia, Kordopatis G., Wyse R.F.G., Gilmore G., Recio-Blanco A., De Laverny P., Hill V., Adibekyan V., Heiter U., Minchev I., Famaey B., Bensby T., Feltzing S., Guiglion G., Korn A.J., Mikolaitis S., Schultheis M., Vallenari A., Bayo A., Carraro G., Flaccomio E., Franciosini E., Hourihane A., Jofre P., Koposov S.E., Lardo C., Lewis J., Lind K., Magrini L., Morbidelli L., Pancino E., Randich S., Sacco G.G., Worley C.C., and Zaggia S.
- Subjects
astro-ph.GA ,Milky Way ,Metallicity ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,evolution [Galaxy] ,Galaxy: disk ,Astronomi, astrofysik och kosmologi ,0103 physical sciences ,stellar content [Galaxy] ,Astronomy, Astrophysics and Cosmology ,10. No inequality ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Galaxy: evolution ,Physics ,Galaxy: stellar content ,010308 nuclear & particles physics ,Turbulence ,Stars: abundances ,abundances [Galaxy] ,Astronomy and Astrophysics ,kinematics and dynamics [Galaxy] ,Thin disc ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,abundances [stars] ,Galaxy: abundance ,Stars ,Distribution function ,Space and Planetary Science ,Galaxy: abundances ,Galaxy: kinematics and dynamics ,Astrophysics of Galaxies (astro-ph.GA) ,Galaxy: kinematics and dynamic ,Astrophysics::Earth and Planetary Astrophysics ,disk [Galaxy] ,Double sequence - Abstract
We investigate, using the Gaia-ESO Survey internal Data-Release 2, the properties of the double sequence of the Milky Way discs (defined chemically as the high-alpha and low-alpha populations), and discuss their compatibility with discs defined by other means such as metallicity, kinematics or positions. This investigation uses two different approaches: in velocity space for stars located in the extended Solar neighbourhood, and in chemical space for stars at different ranges of Galactocentric radii and heights from the plane. The separation we find in velocity space allows us to investigate, in a novel manner, the extent in metallicity of each of the two sequences, identifying them with the two discs, without making any assumption about the shape of their metallicity distribution functions. Then, using the separation in chemical space, we characterise the spatial variation of the slopes of the [alpha/Fe] - [Fe/H] sequences for the thick and thin discs and the way in which the relative proportions of the two discs change across the Galaxy. We find that the thick disc (high-alpha sequence), extends up to [Fe/H]~ +0.2 and the thin disc (low-alpha sequence), at least down to [Fe/H]~ -0.8. Radial and vertical gradients in alpha-abundances are found for the thin disc, with mild spatial variations in its [alpha/Fe] - [Fe/H] paths, whereas for the thick disc we do not detect any such spatial variations. The small variations in the spatial [alpha/Fe] - [Fe/H] paths of the thin disc do not allow us to distinguish between formation models of this structure. On the other hand, the lack of radial gradients and [alpha/Fe] - [Fe/H] variations for the thick disc indicate that the mechanism responsible for the mixing of the metals in the young Galaxy (e.g. radial stellar migration or turbulent gaseous disc) was more efficient before the (present) thin disc started forming., 21 pages, 18 figures, accepted for publication in Astronomy & Astrophysics
- Published
- 2015
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.