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7. Integrable models with twist function and affine Gaudin models

Author

Lacroix, Sylvain, Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), Université de Lyon, University of Hertfordshire (Hatfield (GB)), Marc Magro, and Benoit Vicedo

Subjects
Sigma models, Modèles sigma, Physique mathématique, Modèles de Gaudin, Nonlinear Sciences::Exactly Solvable and Integrable Systems, Field theories, Modèles intégrables, Gaudin models, Théorie des champs, [MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph], Mathematics::Quantum Algebra, Mathematical physics, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Integrable models
Abstract

This thesis deals with a class of integrable field theories called models with twist function. The main examples of such models are integrable non-linear sigma models, such as the Principal Chiral Model, and their deformations. A first obtained result is the proof that the so-called Bi-Yang-Baxter model, which is a two-parameter deformation of the Principal Chiral Model, is also a model with twist function. It is then shown that Yang-Baxter type deformations modify certain global symmetries of the undeformed model into Poisson-Lie symmetries. Another chapter concerns the construction of an infinite number of local charges in involution for all integrable sigma models and their deformations: this result is based on the general formalism shared by all these models as field theories with twist function.The second part of the thesis concerns Gaudin models. These are integrable models associated with Lie algebras. In particular, field theories with twist function are related to Gaudin models associated with affine Lie algebras. A standard approach for studying the spectrum of quantum Gaudin models over finite algebras is the one of Feigin-Frenkel-Reshetikhin. In this thesis, generalisations of this approach are conjectured, motivated and tested. One of them deals with the so-called cyclotomic finite Gaudin models. The second one concerns the Gaudin models associated with affine Lie algebras.; Cette thèse a pour sujet une classe de théories des champs intégrables appelées modèles avec fonction twist. Les principaux exemples de tels modèles sont les modèles sigma non-linéaires intégrables, tel le Modèle Principal Chiral, et leurs déformations. Un premier résultat obtenu est la preuve que le modèle dit de Bi-Yang-Baxter, qui est une déformation à deux paramètres du Modèle Principal Chiral, est lui aussi un modèle avec fonction twist. Il est ensuite montré que les déformations de type Yang-Baxter modifient certaines symétries globales du modèle non déformé en symétries de Poisson-Lie. Un autre chapitre concerne la construction d'une infinité de charges locales en involution pour tous les modèles sigma intégrables et leurs déformations : ce résultat repose sur le formalisme général partagé par tous ces modèles en tant que théories des champs avec fonction twist.La seconde partie de la thèse a pour sujet les modèles de Gaudin. Ceux-ci sont des modèles intégrables associés à des algèbres de Lie. En particulier, les théories des champs avec fonction twist sont liées aux modèles de Gaudin associés à des algèbres de Lie affines. Une approche standard pour l'étude du spectre des modèles de Gaudin quantiques sur des algèbres finies est celle de Feigin-Frenkel-Reshetikhin. Dans cette thèse, des généralisations de cette approche sont conjecturées, motivées et testées. L'une d'elles concerne les modèles de Gaudin finis dits cyclotomiques. La seconde porte sur les modèles de Gaudin associés à des algèbres affines.

Published
2018

8. Parallaxes and infrared photometry of three Y0 dwarfs

Author

Richard L. Smart, Pascal Tremblin, Jane E. Morrison, David S. Amundsen, Federico Marocco, S. K. Leggett, D. J. Pinfield, J. Davy Kirkpatrick, Daniel Apai, Hugh R. A. Jones, ITA, USA, GBR, INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), Steward Observatory, University of Arizona, Lunar and Planetary Laboratory [University of Arizona] (LPL), Infrared Processing and Analysis Center (IPAC), California Institute of Technology (CALTECH), Gemini Observatory [Southern Operations Center], Association of Universities for Research in Astronomy (AURA), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), Maison de la Simulation (MDLS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of Exeter, European Project: 247593,EC:FP7:PEOPLE,FP7-PEOPLE-2009-IRSES,IPERCOOL(2010), Centre for Astrophysics Research [Hatfield], and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
Absolute magnitude, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Metallicity, Infrared telescope, Brown dwarf, FOS: Physical sciences, Astrophysics, 01 natural sciences, Photometry (optics), Observatory, 0103 physical sciences, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, Astronomy, Astronomy and Astrophysics, Astrometry, Effective temperature, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, parallaxes, astrometry, techniques: spectroscopic, brown dwarfs
Abstract

We have followed up the three Y0 dwarfs WISEPA J041022.71+150248.5, WISEPA J173835.53+273258.9 and WISEPC J205628.90+145953.3 using the UKIRT/WFCAM telescope/instruments. We find parallaxes that are more consistent and accurate than previously published values. We estimate absolute magnitudes in photometric pass-bands from $Y$ to $W3$ and find them to be consistent between the three Y0 dwarfs indicating the inherent cosmic absolute magnitude spread of these objects is small. We examine the MKO $J$ magnitudes over the four year time line and find small but significant monotonic variations. Finally we estimate physical parameters from a comparison of spectra and parallax to equilibrium and non-equilibrium models finding values consistent with solar metallicity, an effective temperature of 450-475\,K and log~g of 4.0-4.5., 12 Pages, 10 figures, Accepted by MNRAS

Published
2017
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9. VIRAC: The VVV Infrared Astrometric Catalogue

Author

Richard L. Smart, Janet E. Drew, C. Contreras Peña, P. W. Lucas, Michael A. Kuhn, Federico Marocco, Mariusz Gromadzki, R. Kurtev, Zhenyu Zhang, Dante Minniti, Luigi R. Bedin, J. Borissova, D. J. Pinfield, Hugh R. A. Jones, Leigh C. Smith, ITA, USA, GBR, CHL, Department of Physics [Bath], University of Bath [Bath], Science and Technology Research Institute [Hatfield] (STRI), University of Hertfordshire [Hatfield] (UH), Environment Dept., Instituto de Fisica y Astronomia [Valparaiso], Universidad de Valparaiso [Chile], Centre for Astrophysics Research [Hatfield], Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and School of Physics, Astronomy and Mathematics [Hatfield]

Subjects
Vista Variables in the Via Lactea, stars: kinematics and dynamics, solar neighbourhood, Library science, FOS: Physical sciences, 01 natural sciences, proper motions, 0103 physical sciences, kinematics and dynamics [Stars], 010303 astronomy & astrophysics, License, Solar and Stellar Astrophysics (astro-ph.SR), [PHYS]Physics [physics], Physics, Brown dwarfs, Parallaxes, 010308 nuclear & particles physics, Astronomy, Astronomy and Astrophysics, Creative commons, kinematics and dynamics [Galaxy], Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), parallaxes, Proper motions, Solar neighbourhood, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Galaxy: kinematics and dynamics, brown dwarfs
Abstract

We present VIRAC version 1, a near-infrared proper motion and parallax catalogue of the VISTA VVV survey for 312,587,642 unique sources averaged across all overlapping pawprint and tile images covering 560 deg$^2$ of the bulge of the Milky Way and southern disk. The catalogue includes 119 million high quality proper motion measurements, of which 47 million have statistical uncertainties below 1 mas yr$^{-1}$. In the 11$, Comment: Accepted for publication in MNRAS. See http://vvv.herts.ac.uk

Published
2017
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10. The gaia -ESO survey: calibration strategy

Author

Pancino, E., Lardo, C., Altavilla, G., Marinoni, S., Ragaini, S., Cocozza, G., Bellazzini, M., Sabbi, E., Zoccali, M., Donati, P., Heiter, U., Koposov, S. E., Blomme, R., Morel, T., Símon-Díaz, S., Lobel, A., Soubiran, C., Montalban, J., Valentini, M., Casey, A. R., Blanco-Cuaresma, S., Jofré, P., Worley, C. C., Magrini, L., Hourihane, A., François, P., Feltzing, S., Gilmore, G., Randich, S., Asplund, M., Bonifacio, P., Drew, J. E., Jeffries, R. D., Micela, G., Vallenari, A., Alfaro, E. J., Allende Prieto, C., Babusiaux, C., Bensby, T., angela Bragaglia, Flaccomio, E., Hambly, N., Korn, A. J., Lanzafame, A. C., Smiljanic, R., Eck, S., Walton, N. A., Bayo, A., Carraro, G., Costado, M. T., Damiani, F., Edvardsson, B., Franciosini, E., Frasca, A., Lewis, J., Monaco, L., Morbidelli, L., Prisinzano, L., Sacco, G. G., Sbordone, L., Sousa, S. G., Zaggia, S., Koch, A., Ministero dell'Istruzione, dell'Università e della Ricerca, Knut and Alice Wallenberg Foundation, European Research Council, Swedish National Space Board, Belgian Science Policy Office, National Science Centre (Poland), European Science Foundation, Ministerio de Economía y Competitividad (España), Pancino E., Lardo C., Altavilla G., Marinoni S., Ragaini S., Cocozza G., Bellazzini M., Sabbi E., Zoccali M., Donati P., Heiter U., Koposov S.E., Blomme R., Morel T., Simon-Diaz S., Lobel A., Soubiran C., Montalban J., Valentini M., Casey A.R., Blanco-Cuaresma S., Jofre P., Worley C.C., Magrini L., Hourihane A., Francois P., Feltzing S., Gilmore G., Randich S., Asplund M., Bonifacio P., Drew J.E., Jeffries R.D., Micela G., Vallenari A., Alfaro E.J., Allende Prieto C., Babusiaux C., Bensby T., Bragaglia A., Flaccomio E., Hambly N., Korn A.J., Lanzafame A.C., Smiljanic R., Van Eck S., Walton N.A., Bayo A., Carraro G., Costado M.T., Damiani F., Edvardsson B., Franciosini E., Frasca A., Lewis J., Monaco L., Morbidelli L., Prisinzano L., Sacco G.G., Sbordone L., Sousa S.G., Zaggia S., Koch A., Institut national de recherche et de sécurité (Vandoeuvre lès Nancy) (INRS ( Vandoeuvre lès Nancy)), Royal Observatory of Belgium [Brussels] (ROB), Science et Ingénierie des Matériaux et Procédés (SIMaP ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), M2A 2017, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Leibniz-Institut für Astrophysik Potsdam (AIP), Focas Research Institute, Dublin Institute of Technology, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), INAF - Osservatorio Astronomico di Palermo (OAPa), Istituto Nazionale di Astrofisica (INAF), Economía Política y Hacienda Pública, Estadística Económica y Empresarial y Política Económica, Universidad de Castilla-La Mancha (UCLM), Department of Astronomy and Space Physics [Uppsala], Uppsala University, INAF - Osservatorio Astrofisico di Catania (OACT), Institut d'Astronomie et d'Astrophysique, Université libre de Bruxelles (ULB), University of Turin, Department of Physiology and Pharmacology, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome]-Réseau International des Instituts Pasteur (RIIP)-Institut Pasteur, Fondation Cenci Bolognetti - Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Réseau International des Instituts Pasteur (RIIP), Pôle Gérontologie, and Centre Hospitalier Universitaire de Nice (CHU Nice)

Subjects
Stars: abundance, Milky Way, FOS: Physical sciences, Techniques: spectroscopic, Astrophysics, Parameter space, Surveys, 01 natural sciences, Spectral line, surveys, 0103 physical sciences, Calibration, Emission spectrum, Survey, 010303 astronomy & astrophysics, Galaxy: general, Solar and Stellar Astrophysics (astro-ph.SR), QC, general [Galaxy], QB, Physics, [PHYS]Physics [physics], Observational error, 010308 nuclear & particles physics, Techniques: radial velocitie, Stars: abundances, Astronomy and Astrophysics, Ranging, radial velocities [techniques], [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, abundances [stars], Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Techniques: radial velocities, stars: abundances, techniques: spectroscopic, techniques: radial velocities, spectroscopic [techniques], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

The Gaia-ESO survey (GES) is now in its fifth and last year of observations and has produced tens of thousands of high-quality spectra of stars in all Milky Way components. This paper presents the strategy behind the selection of astrophysical calibration targets, ensuring that all GES results on radial velocities, atmospheric parameters, and chemical abundance ratios will be both internally consistent and easily comparable with other literature results, especially from other large spectroscopic surveys and from Gaia. The calibration of GES is particularly delicate because of (i) the large space of parameters covered by its targets, ranging from dwarfs to giants, from O to M stars; these targets have a large wide of metallicities and also include fast rotators, emission line objects, and stars affected by veiling; (ii) the variety of observing setups, with different wavelength ranges and resolution; and (iii) the choice of analyzing the data with many different state-of-the-art methods, each stronger in a different region of the parameter space, which ensures a better understanding of systematic uncertainties. An overview of the GES calibration and homogenization strategy is also given, along with some examples of the usage and results of calibrators in GES iDR4, which is the fourth internal GES data release and will form the basis of the next GES public data release. The agreement between GES iDR4 recommended values and reference values for the calibrating objects are very satisfactory. The average offsets and spreads are generally compatible with the GES measurement errors, which in iDR4 data already meet the requirements set by the main GES scientific goals.© ESO, 2017., This work was partly supported by the European Union FP7 program through ERC grant number 320360 and by the Leverhulme Trust through grant RPG-2012-541. We acknowledge the support from INAF and Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR) in the form of the grant >Premiale VLT 2012>. The results presented here benefit from discussions held during the Gaia-ESO workshops and conferences supported by the ESF (European Science Foundation) through the GREAT Research Network Programme. S.F. and T.B. acknowledge the support from the New Milky Way project funded by a grant from the Knut and Alice Wallenberg foundation. C.L. gratefully acknowledges financial support from the European Research Council (ERC-CoG-646928, Multi-Pop, PI: N. Bastian). U.H. and A.J.K acknowledge support from the Swedish National Space Board (Rymdstyrelsen). The research of A.L. has been subsidized by the Belgian Federal Science Policy Office under contract No. BR/143/A2/BRASS. R.S. acknowledges support by the National Science Center of Poland through grant 2014/15/B/ST9/03981. C.A.P. is thankful for support from the Spanish Ministry of Economy and Competitiveness (MINECO) through grant AYA2014-56359-P.J.M. acknowledges support from the ERC Consolidator Grant funding scheme (project STARKEY, G.A. No. 615604). T.M. acknowledges financial support from Belspo for contract PRODEX Gaia-DPAC. S.G.S acknowledges the support by Fundacao para a Ciencia e Tecnologia (FCT) through national funds and a research grant (project ref. UID/FIS/04434/2013, and PTDC/FIS-AST/7073/2014). S.G.S. also acknowledge the support from FCT through Investigador FCT contract of reference IF/00028/2014 and POPH/FSE (EC) by FEDER funding through the program >Programa Operacional de Factores de Competitividade - COMPETE>. L.S. acknowledges support by the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009, awarded to The Millennium Institute of Astrophysics (MAS). M.Z. acknowledges support by the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009, awarded to The Millennium Institute of Astrophysics (MAS), by Fondecyt Regular 1150345 and by the BASAL CATA PFB-06. E.J.A. and M.T.C acknowledge the financial support from the Spanish Ministerio de Economia y Competitividad, through grant AYA2013-40611-P.S.Z. acknowledge the support from the INAF grant >PRIN INAF 2014>, >Star won't tell their ages to Gaia, Galactic Archaelogy with wide-area asterosismic>.

Published
2017
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11. The 67P/Churyumov-Gerasimenko observation campaign in support of the Rosetta mission

Author

Benoit Carry, M. F. A'Hearn, Sebastien Besse, Michaël Gillon, M. J. Mumma, Galin Borisov, B. Rajkumar, Janet E. Drew, Olga Muñoz, Viktor Afanasiev, Tarik Zegmott, Lucas Paganini, D. Bodewits, Rita Schulz, Emily Kramer, Adam J. McKay, Diane H. Wooden, J. de León, Michael Schmidt, Geraint H. Jones, S. Haque, Andrew McNeill, Fernando Moreno, Sara Faggi, P. J. Gutiérrez, Jérémie Lasue, Aurélie Guilbert-Lepoutre, J. M. Sunshine, Javier Licandro, Zhong-Yi Lin, Pedro Lacerda, Philippe Rousselot, Jose Luis Ortiz, Nicolas Biver, Marco Micheli, J. J. López-Moreno, Matthew M. Knight, Jon Marchant, Detlef Koschny, Dominik R. G. Schleicher, F. Aceituno, Michael S. P. Kelley, Colin Snodgrass, G. P. Tozzi, Michael A. DiSanti, Karen J. Meech, Olivier Hainaut, Alfredo Sota, Niklas J. T. Edberg, Edith Hadamcik, Rene Duffard, Rosita Kokotanekova, Erika L. Gibb, Damien Hutsemekers, E. Ramos, Y. Ramanjooloo, A. Guijarro, Ulrich Hopp, Luisa Lara, Stephen C. Lowry, Tim Lister, Anita L. Cochran, V. Casanova, Pablo Santos-Sanz, J. Kleyna, R. Hedrosa, M. Pajuelo, A. K. Sen, Cyrielle Opitom, Emmanuel Jehin, A. Thompson, Alan Fitzsimmons, Geronimo L. Villanueva, E. J. W. de Mooij, Stefano Bagnulo, C. Ries, Boncho P. Bonev, O. Ivanova, Amy Mainzer, John K. Davies, Blair C. Conn, Anny Chantal Levasseur-Regourd, P. Nikolov, Auni Somero, Nikolai Kiselev, Lori M. Feaga, Maria Monguió, Francisco J. Pozuelos, A. Stinson, M. Delacruz, Björn Davidsson, Jacqueline V. Keane, M. Kluge, Dean C. Hines, Simon F. Green, Jean Manfroid, James Bauer, Silvia Protopapa, M. de Val-Borro, T. Pursimo, Xiaobin Wang, Cecilia Tubiana, Hermann Boehnhardt, Masafumi Yagi, I. Mohammed, Vera Rosenbush, F. Hoyo, Harry Lehto, G. Bergond, B. Yang, Méabh Hyland, Arno Riffeser, Hideaki Fujiwara, Erin L. Ryan, B. Zaprudin, School of Physical Sciences [Milton Keynes], The Open University [Milton Keynes] ( OU ), Department of Astronomy [College Park], University of Maryland [College Park], Instituto de Astrofísica de Andalucía ( IAA ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), Special Astrophysical Observatory of the Russian Academy of Sciences ( SAO ), Russian Academy of Sciences [Moscow] ( RAS ), Armagh Observatory [Armagh], Jet Propulsion Laboratory ( JPL ), NASA-California Institute of Technology ( CALTECH ), Centro Astronómico Hispano Alemán, European Space Astronomy Center ( ESAC ), European Space Agency ( ESA ), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Department of Physics [Washington], American University Washington D.C. ( AU ), Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences, Joseph Louis LAGRANGE ( LAGRANGE ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Mécanique Céleste et de Calcul des Ephémérides ( IMCCE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université de Lille-Centre National de la Recherche Scientifique ( CNRS ), McDonald Observatory, University of Texas at Austin [Austin], Research School of Astronomy and Astrophysics [Canberra] ( RSAA ), Australian National University ( ANU ), Gemini Observatory [Southern Operations Center], Association of Universities for Research in Astronomy ( AURA ), UK Astronomy Technology Centre ( UK ATC ), Science and Technology Facilities Council ( STFC ), Universidad de La Laguna ( ULL ), Instituto de Astrofisica de Canarias ( IAC ), Astrophysics Research Centre [Belfast] ( ARC ), Queen's University [Belfast] ( QUB ), Catholic University of America, Astrochemistry Laboratory [Greenbelt], NASA Goddard Space Flight Center ( GSFC ), Department of Astrophysical Sciences [Princeton], Princeton University, Institute for Astronomy [Honolulu], University of Hawaii at Manoa ( UHM ), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] ( UH ), Swedish Institute of Space Physics [Uppsala] ( IRF ), National Astronomical Observatory of Japan ( NAOJ ), Department of Physics and Astronomy [Columbia], University of Missouri-Columbia, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules ( UTINAM ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), European Southern Observatory ( ESO ), Department of Physics [Trinidad], The University of the West Indies, Space Telescope Science Institute ( STSci ), Ludwig-Maximilians University [Munich] ( LMU ), Astronomical Institute of the Slovak Academy of Sciences, Slovak Academy of Science [Bratislava] ( SAS ), Mullard Space Science Laboratory ( MSSL ), University College of London [London] ( UCL ), Centre for Planetary Sciences [UCL/Birkbeck] ( CPS ), Main Astronomical Observatory of NAS of Ukraine ( MAO ), National Academy of Sciences of Ukraine ( NASU ), Research and Scientific Support Department, ESTEC ( RSSD ), European Space Research and Technology Centre ( ESTEC ), European Space Agency ( ESA ) -European Space Agency ( ESA ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Tuorla Observatory, University of Turku, Institute of Astronomy [Taiwan] ( IANCU ), National Central University [Taiwan] ( NCU ), Las Cumbres Observatory ( LCO ), Centre for Astrophysics and Planetary Science [Canterbury] ( CAPS ), University of Kent [Canterbury], Astrophysics Research Institute [Liverpool] ( ARI ), Liverpool John Moores University ( LJMU ), ESA SSA-NEO Coordination Centre, Caribbean Institute of Astronomy ( CARINA ), Pontificia Universidad Católica del Perú ( PUCP ), Nordic Optical Telescope ( NOT ), SETI Institute, Lowell Observatory [Flagstaff], European Space Agency, Scientific Support Office, Assam University, INAF - Osservatorio Astrofisico di Arcetri ( OAA ), Istituto Nazionale di Astrofisica ( INAF ), Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences [Beijing] ( CAS ), Yunnan Observatories, Chinese Academy of Sciences [Changchun Branch] ( CAS ), NASA Ames Research Center ( ARC ), Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), University of Maryland System-University of Maryland System, Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Special Astrophysical Observatory of the Russian Academy of Sciences (SAO), Russian Academy of Sciences [Moscow] (RAS), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Centro Astronómico Hispano Alemán, Observatorio de Calar Alto (CAHA), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, American University Washington D.C. (AU), Institute of Astronomy of the Bulgarian Academy of Sciences, Bulgarian Academy of Sciences (BAS), 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, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Research School of Astronomy and Astrophysics [Canberra] (RSAA), Australian National University (ANU), Association of Universities for Research in Astronomy (AURA), UK Astronomy Technology Centre (UK ATC), Science and Technology Facilities Council (STFC), Universidad de La Laguna [Tenerife - SP] (ULL), Instituto de Astrofisica de Canarias (IAC), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), NASA Goddard Space Flight Center (GSFC), University of Hawai‘i [Mānoa] (UHM), University of Hertfordshire [Hatfield] (UH), Swedish Institute of Space Physics [Uppsala] (IRF), National Astronomical Observatory of Japan (NAOJ), Department of Physics and Astronomy [Columbia] (Mizzou Physics), University of Missouri [Columbia] (Mizzou), University of Missouri System-University of Missouri System, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Space Telescope Science Institute (STSci), Ludwig-Maximilians-Universität München (LMU), Slovak Academy of Science [Bratislava] (SAS), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Centre for Planetary Sciences [UCL/Birkbeck] (CPS), Main Astronomical Observatory of NAS of Ukraine (MAO), National Academy of Sciences of Ukraine (NASU), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Las Cumbres Observatory (LCO), Centre for Astrophysics and Planetary Science [Canterbury] (CAPS), Astrophysics Research Institute [Liverpool] (ARI), Liverpool John Moores University (LJMU), Caribbean Institute of Astronomy (CARINA), Pontificia Universidad Católica del Perú (PUCP), Nordic Optical Telescope (NOT), ESA Scientific Support Office, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Chinese Academy of Sciences [Beijing] (CAS), Chinese Academy of Sciences [Changchun Branch] (CAS), NASA Ames Research Center (ARC), NASA-California Institute of Technology (CALTECH), Agence Spatiale Européenne = European Space Agency (ESA), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP)

Subjects
Future studies, History, 010504 meteorology & atmospheric sciences, General Mathematics, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], General Physics and Astronomy, FOS: Physical sciences, Context (language use), 01 natural sciences, Astrobiology, Jupiter, 0103 physical sciences, 010303 astronomy & astrophysics, QC, 0105 earth and related environmental sciences, QB, Earth and Planetary Astrophysics (astro-ph.EP), comet 67P/Churyumov?Gerasimenko, Rosetta, solar system, observational astronomy, ta115, Spacecraft, business.industry, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], General Engineering, Articles, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Early results, business, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Earth and Planetary Astrophysics
Abstract

We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov-Gerasimenko from before Rosetta's arrival until nearly the end of mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft, and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively `well behaved' comet, typical of Jupiter family comets and with activity patterns that repeat from orbit-to-orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends -- in this paper we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies., Comment: Author prepared version; final published version available at journal. 22 pages

Published
2017
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12. Modelling diffraction by facetted particles

Author

Evelyn Hesse, Paul H. Kaye, Andreas Macke, Anthony J. Baran, Stephan Havemann, Zbigniew Ulanowski, School of Physics, Astronomy and Mathematics, Science & Technology Research Institute, Centre for Atmospheric and Instrumentation Research, Light Scattering & Radiactive Properties, and Particle Instrumentation

Subjects
Diffraction, Physics, Range (particle radiation), Radiation, business.industry, Phase (waves), Diffraction Facetted particle Kirchhoff approximation Light scattering, Discrete dipole approximation, Size parameter, Aspect ratio (image), Molecular physics, Atomic and Molecular Physics, and Optics, Light scattering, Reflection (mathematics), Optics, business, Spectroscopy
Abstract

A method to approximate azimuthally resolved light scattering patterns and phase functions due to diffraction and external reflection by strongly absorbing facetted particles is demonstrated for a cube and compared with results from an exact method, T-matrix. A phase function averaged over a range of orientations of a strongly absorbing hexagonal column of aspect ratio unity has been calculated and tested against Discrete Dipole Approximation (DDA) results for a size parameter of 50., Final Accepted Version

Published
2012
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13. IR imaging surveys of AGB stars in the Magellanic Clouds

Author

Maria-Rosa L. Cioni and School of Physics, Astronomy and Mathematics

Subjects
Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), ComputingMilieux_THECOMPUTINGPROFESSION, ComputingMethodologies_MISCELLANEOUS, General Engineering, FOS: Physical sciences, ComputingMilieux_LEGALASPECTSOFCOMPUTING, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy, Stars, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

“The original publication is available at www.edpsciences.org/eas”. Copyright EAS/EDP Sciences., AGB stars are ideal IR targets because they are cool and bright. Most of them escaped detection in optical or shallow IR surveys in the eighties contributing to the puzzling missing number of AGB stars with respect to theoretical predictions and former stages of evolution. Observations and AGB models have advanced steadily in the following decades providing us with an almost complete view of the AGB stars in the Magellanic Clouds. Their properties are tracers of structure and chemistry across galaxies. New surveys will be able to fill-in the gaps, in terms of sensitivity and monitoring, providing new constraints for the formation and evolution of the Magellanic Clouds., other

Published
2009
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14. The Gaia-ESO Survey: Empirical determination of the precision of stellar radial velocities and projected rotation velocities

Author

Annette M. N. Ferguson, Francesco Damiani, Gerard Gilmore, Angela Bragaglia, Martin Asplund, Giovanni Carraro, Vanessa Hill, L. Morbidelli, Paula Jofre, Antonio Frasca, Elena Pancino, A. C. Lanzafame, M. T. Costado, Bengt Edvardsson, A. Hourihane, Thomas Bensby, Antonella Vallenari, T. Prusti, Andreas Korn, Nicholas A. Walton, Carmela Lardo, Lorenzo Monaco, Sofia Feltzing, Ulrike Heiter, P. de Laverny, L. Prisinzano, Emilio J. Alfaro, C. Babusiaux, E. Franciosini, Clare Worley, Hans-Walter Rix, C. Allende Prieto, S. G. Sousa, Laura Magrini, Rodolfo Smiljanic, Christophe Martayan, G. G. Sacco, Maria Bergemann, P. Francois, R. J. Jackson, R. Blomme, Alejandra Recio-Blanco, Nigel Hambly, Sofia Randich, Karin Lind, Piercarlo Bonifacio, Gianni Marconi, R. D. Jeffries, Luca Sbordone, James R. Lewis, S. Van Eck, Amelia Bayo, James Binney, I. Neguerela, Simone Zaggia, Ettore Flaccomio, Janet E. Drew, Mike Irwin, Giuseppina Micela, Sergey E. Koposov, Thomas Masseron, 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., Allende Prieto C., 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., Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Astrofísica Estelar (AE), Keele University [Keele], Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), Lund Observatory, Lund University [Lund], INAF - Osservatorio Astronomico di Palermo (OAPa), Istituto Nazionale di Astrofisica (INAF), Agence Spatiale Européenne (ESA), European Space Agency (ESA), INAF - Osservatorio Astronomico di Padova (OAPD), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Royal Observatory of Belgium [Brussels] (ROB), INAF - Osservatorio Astronomico di Bologna (OABO), Institut de Mécanique des Fluides et des Solides (IMFS), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Uppsala], Uppsala University, INAF - Osservatorio Astrofisico di Catania (OACT), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astronomie et d'Astrophysique, Université libre de Bruxelles (ULB), University of Turin, Ecole Polytechnique Fédérale de Lausanne (EPFL), Max-Planck-Institut für Astrophysik (MPA), Max-Planck-Gesellschaft, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Fisica Nucleare, Sezione di Milano (INFN), Istituto Nazionale di Fisica Nucleare (INFN), 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, and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Metallicity, FOS: Physical sciences, stars: kinematics and dynamics, open clusters and associations: general, Open clusters and associations: general, Stars: kinematics and dynamics, Astronomy and Astrophysics, Space and Planetary Science, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Spectral line, Normal distribution, Astronomi, astrofysik och kosmologi, Observatory, Astronomy, Astrophysics and Cosmology, Astrophysics::Solar and Stellar Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), kinematics and dynamics [stars], QC, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, QB, Astronomía y Astrofísica, [PHYS]Physics [physics], Physics, Very Large Telescope, Kinematics and dynamics, Astrometry, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Satellite, Astrophysics::Earth and Planetary Astrophysics, general [open clusters and associations], Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

The Gaia-ESO Survey (GES) is a large public spectroscopic survey at the European Southern Observatory Very Large Telescope. A key aim is to provide precise radial velocities (RVs) and projected equatorial velocities (v sin i) for representative samples of Galactic stars, that will complement information obtained by the Gaia astrometry satellite. We present an analysis to empirically quantify the size and distribution of uncertainties in RV and v sin i using spectra from repeated exposures of the same stars. We show that the uncertainties vary as simple scaling functions of signal-to-noise ratio (S/N) and v sin i, that the uncertainties become larger with increasing photospheric temperature, but that the dependence on stellar gravity, metallicity and age is weak. The underlying uncertainty distributions have extended tails that are better represented by Student's t-distributions than by normal distributions. Parametrised results are provided, that enable estimates of the RV precision for almost all GES measurements, and estimates of the v sin i precision for stars in young clusters, as a function of S/N, v sin i and stellar temperature. The precision of individual high S/N GES RV measurements is 0.22-0.26 km/s, dependent on instrumental configuration., 13 pages, accepted for publication in Astronomy & Astrophysics

Published
2015
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15. Gaia -ESO Survey: Analysis of pre-main sequence stellar spectra

Author

Antonio Frasca, G. G. Sacco, Ignacio Negueruela, Hugo M. Tabernero, Andreas Korn, Martin Asplund, C. Babusiaux, Loredana Prisinzano, Francesco Damiani, Nigel Hambly, M. T. Costado, G. Carraro, Gerry Gilmore, Giuseppina Micela, Emilio J. Alfaro, Piercarlo Bonifacio, Annette M. N. Ferguson, A. Hourihane, Maria Bergemann, N. A. Walton, E. Brugaletta, Manuel Meyer, John D. Lewis, H. W. Rix, Michael G. Irwin, Vardan Adibekyan, R. Blomme, P. Francois, R. D. Jeffries, A. C. Lanzafame, Sergey E. Koposov, Lorenzo Spina, James Binney, Thomas Masseron, L. Morbidelli, D. Montes, K. Biazzo, S. G. Sousa, Antonella Vallenari, Rodolfo Smiljanic, J. M. Alcalá, Thomas Bensby, C. Allende Prieto, Sergio Messina, Luca Sbordone, Amelia Bayo, A. Bragaglia, Simone Zaggia, C. C. Worley, Janet E. Drew, Ettore Flaccomio, S. Van Eck, Paula Jofre, Laura Magrini, Bengt Edvardsson, Gianni Marconi, J. I. González Hernández, Michiel Cottaar, Rosaria Bonito, Lorenzo Monaco, Ulrike Heiter, J. F. Gameiro, Carmela Lardo, Sofia Feltzing, E. Franciosini, T. Prusti, R. J. Jackson, Vanessa Hill, Sofia Randich, Karin Lind, Ch. Martayan, E. Delgado Mena, A. Klutsch, INAF - Osservatorio Astrofisico di Catania (OACT), Istituto Nazionale di Astrofisica (INAF), University of Turin, INAF - Osservatorio Astrofisico di Arcetri (OAA), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto, Istituto di Astrofisica Spaziale e Fisica cosmica - Palermo (IASF-Pa), Keele University [Keele], Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), Lund Observatory, Lund University [Lund], INAF - Osservatorio Astronomico di Palermo (OAPa), Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Señal [Alicante] (DFESTS), Universidad de Alicante, Agence Spatiale Européenne (ESA), European Space Agency (ESA), Laboratoire d'astrophysique de l'observatoire de Besançon (UMR 6091) (LAOB), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Royal Observatory of Belgium [Brussels] (ROB), INAF - Osservatorio Astronomico di Bologna (OABO), Institut d'Astronomie et d'Astrophysique, Université libre de Bruxelles (ULB), Uppsala University, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Ecole Polytechnique Fédérale de Lausanne (EPFL), Max-Planck-Institut für Astrophysik (MPA), Max-Planck-Gesellschaft, Istituto Nazionale di Fisica Nucleare, Sezione di Milano (INFN), Istituto Nazionale di Fisica Nucleare (INFN), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), 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), Lanzafame A.C., Frasca A., Damiani F., Franciosini E., Cottaar M., Sousa S.G., Tabernero H.M., Klutsch A., Spina L., Biazzo K., Prisinzano L., Sacco G.G., Randich S., Brugaletta E., Delgado Mena E., Adibekyan V., Montes D., Bonito R., Gameiro J.F., Alcala J.M., Gonzalez Hernandez J.I., Jeffries R., Messina S., Meyer M., Gilmore G., Asplund M., Binney J., Bonifacio P., Drew J.E., Feltzing S., Ferguson A.M.N., Micela G., Negueruela I., Prusti T., Rix H.-W., Vallenari A., Alfaro E.J., Allende Prieto C., Babusiaux C., Bensby T., Blomme R., Bragaglia A., Flaccomio E., Francois P., Hambly N., Irwin M., Koposov S.E., Korn A.J., Smiljanic R., Van Eck S., Walton N., Bayo A., Bergemann M., Carraro G., Costado M.T., Edvardsson B., Heiter U., Hill V., Hourihane A., Jackson R.J., Jofre P., Lardo C., Lewis J., Lind K., Magrini L., Marconi G., Martayan C., Masseron T., Monaco L., Morbidelli L., Sbordone L., Worley C.C., Zaggia S., Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Astrofísica Estelar (AE), Lanzafame, A., Frasca, A., Damiani, F., Franciosini, E., Cottaar, M., Sousa, S., Tabernero, H., Klutsch, A., Spina, L., Biazzo, K., Prisinzano, L., Sacco, G., Randich, S., Brugaletta, E., Delgado Mena, E., Adibekyan, V., Montes, D., Bonito, R., Gameiro, J., Alcalá, J., González Hernández, J., Jeffries, R., Messina, S., Meyer, M., Gilmore, G., Asplund, M., Binney, J., Bonifacio, P., Drew, J., Feltzing, S., Ferguson, A., Micela, G., Negueruela, I., Prusti, T., Rix, H., Vallenari, A., Alfaro, E., Allende Prieto, C., Babusiaux, C., Bensby, T., Blomme, R., Bragaglia, A., Flaccomio, E., Francois, P., Hambly, N., Irwin, M., Koposov, S., Korn, A., Smiljanic, R., Van Eck, S., Walton, N., Bayo, A., Bergemann, M., Carraro, G., Costado, M., Edvardsson, B., Heiter, U., Hill, V., Hourihane, A., Jackson, R., Jofré, P., Lardo, C., Lewis, J., Lind, K., Magrini, L., Marconi, G., Martayan, C., Masseron, T., Monaco, L., Morbidelli, L., Sbordone, L., Worley, C., and Zaggia, S.

Subjects
Accuracy and precision, Population, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, stars: pre-main sequence, Surveys, fundamental parameters [Stars], Astronomical spectroscopy, surveys, Angular diameter, pre-main sequence [Stars], Astrophysics::Solar and Stellar Astrophysics, Survey, data analysis [Methods], education, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Astronomía y Astrofísica, Physics, education.field_of_study, general [Open clusters and associations], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Stars: fundamental parameter, Astronomy and Astrophysic, Effective temperature, open clusters and associations: general, Surface gravity, methods: data analysis, Accretion (astrophysics), Stars, Astrophysics - Solar and Stellar Astrophysics, Methods: data analysis, Open clusters and associations: general, Stars: fundamental parameters, Stars: pre-main sequence, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics::Earth and Planetary Astrophysics, stars: fundamental parameters, Methods: data analysi
Abstract

This paper describes the analysis of UVES and GIRAFFE spectra acquired by the Gaia-ESO Public Spectroscopic Survey in the fields of young clusters whose population includes pre-main sequence (PMS) stars. Both methods that have been extensively used in the past and new ones developed in the contest of the Gaia-ESO survey enterprise are available and used. The internal precision of these quantities is estimated by inter-comparing the results obtained by such different methods, while the accuracy is estimated by comparison with independent external data, like effective temperature and surface gravity derived from angular diameter measurements, on a sample of benchmarks stars. Specific strategies are implemented to deal with fast rotation, accretion signatures, chromospheric activity, and veiling. The analysis carried out on spectra acquired in young clusters' fields during the first 18 months of observations, up to June 2013, is presented in preparation of the first release of advanced data products. Stellar parameters obtained with the higher resolution and larger wavelength coverage from UVES are reproduced with comparable accuracy and precision using the smaller wavelength range and lower resolution of the GIRAFFE setup adopted for young stars, which allows us to provide with confidence stellar parameters for the much larger GIRAFFE sample. Precisions are estimated to be $\approx$ 120 K r.m.s. in Teff, $\approx$0.3 dex r.m.s. in logg, and $\approx$0.15 dex r.m.s. in [Fe/H], for both the UVES and GIRAFFE setups., 22 pages, 18 figures, accepted for publication on A&A

Published
2015
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16. The Gaia-ESO Survey: Extracting diffuse interstellar bands from cool star spectra

Author

Puspitarini, L., Lallement, R., Babusiaux, C., Chen, H-C, Bonifacio, P., Sbordone, L., Caffau, E., Duffau, S., Hill, V., Monreal-Ibero, A., Royer, F., Arenou, Frédéric, Peralta, R., Drew, J., Bonito, R., Lopez-Santiago, J., Alfaro, E., Bensby, T., Bragaglia, A., Flaccomio, E., Lanzafame, A., Pancino, E., Recio-Blanco, A., Smiljanic, R., Costado, M, Lardo, C., de Laverny, P., Zwitter, T., Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), 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, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), Istituto di Astrofisica Spaziale e Fisica cosmica - Palermo (IASF-Pa), Istituto Nazionale di Astrofisica (INAF), INAF - Osservatorio Astrofisico di Catania (OACT), INAF - Osservatorio Astronomico di Bologna (OABO), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
dust extinction, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics::Cosmology and Extragalactic Astrophysics, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Galaxy: general, Astrophysics::Galaxy Astrophysics, ISM: general, ISM: lines and bands
Abstract

International audience; Aims. We study how diffuse interstellar bands (DIBs) measured toward distance-distributed target stars can be used to locate dense interstellar (IS) clouds in the Galaxy and probe a line-of-sight (LOS) kinematical structure, a potentially useful tool when gaseous absorption lines are saturated or not available in the spectral range. Cool target stars are numerous enough for this purpose.Methods. We devised automated DIB-fitting methods appropriate for cool star spectra and multiple IS components. The data were fitted with a combination of a synthetic stellar spectrum, a synthetic telluric transmission, and empirical DIB profiles. The initial number of DIB components and their radial velocity were guided by HI 21 cm emission spectra, or, when available in the spectral range, IS neutral sodium absorption lines. For NaI, radial velocities of NaI lines and DIBs were maintained linked during a global simultaneous fit. In parallel, stellar distances and extinctions were estimated self-consistently by means of a 2D Bayesian method from spectroscopically-derived stellar parameters and photometric data.Results. We have analyzed Gaia-ESO Survey (GES) spectra of 225 stars that probe between ∼2 and 10 kpc long LOS in five different regions of the Milky Way. The targets are the two CoRoT fields, two open clusters (NGC 4815 and γ Vel), and the Galactic bulge. Two OGLE fields toward the bulge observed before the GES are also included (205 target stars). Depending on the observed spectral intervals, we extracted one or more of the following DIBs: λλ 6283.8, 6613.6, and 8620.4. For each field, we compared the DIB strengths with the Bayesian distances and extinctions, and the DIB Doppler velocities with the HI emission spectra.Conclusions. For all fields, the DIB strength and the target extinction are well correlated. For targets that are widely distributed in distance, marked steps in DIBs and extinction radial distance profiles match each other and broadly correspond to the expected locations of spiral arms. For all fields, the DIB velocity structure agrees with HI emission spectra, and all detected DIBs correspond to strong NaI lines. This illustrates how DIBs can be used to locate the Galactic interstellar gas and to study its kinematics at the kpc scale, as illustrated by Local and Perseus Arm DIBs that differ by > ∼ 30 km s −1 , in agreement with HI emission spectra. On the other hand, if most targets are located beyond the main absorber, DIBs can trace the differential reddening within the field.

Published
2015
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17. The Onsala blind 6.7 GHz survey of the galactic plane: new methanol masers in the northern hemisphere

Author

Pestalozzi, M. R., Minier, V., Booth, R. S., Conway, J. E., and School of Physics, Astronomy and Mathematics

Subjects
Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics
Abstract

We review the state of the Onsala blind survey of the galactic plane, searching for new 6.7 GHz methanol masers. We also describe preliminary results of millimeter follow-up observations of the new detections and high resolution observations using the EVN. We conclude that blind surveys are important to complement targeted searches done until now and give the possibility to detect new classes of objects., 4 pages, 2 figures, to appear in Cosmic Masers: from Protostars to Black Holes, IAU 206, Eds. V. Migenes et al., ASP Conference Series

Published
2002
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18. An integrable deformation of the AdS_5 x S^5 superstring action

Author

Delduc, Francois, Magro, Marc, Vicedo, Benoit, Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), Delduc, François, and École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL)

Subjects
High Energy Physics - Theory, High Energy Physics - Theory (hep-th), [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], FOS: Physical sciences, [PHYS.HTHE] Physics [physics]/High Energy Physics - Theory [hep-th]
Abstract

An integrable deformation of the type IIB AdS_5 x S^5 superstring action is presented. The deformed field equations, Lax connection, and kappa-symmetry transformations are given. The original psu(2,2|4) symmetry is expected to become q-deformed., 5 pages

Published
2013

19. Alleviating the non-ultralocality of coset sigma models through a generalized Faddeev-Reshetikhin procedure

Author

Benoit Vicedo, Marc Magro, Francois Delduc, Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), and École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL)

Subjects
High Energy Physics - Theory, Physics, Nuclear and High Energy Physics, Integrable system, Discretization, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Equations of motion, FOS: Physical sciences, 01 natural sciences, symbols.namesake, Chiral model, Nonlinear Sciences::Exactly Solvable and Integrable Systems, High Energy Physics - Theory (hep-th), Symmetric space, 0103 physical sciences, Lax pair, symbols, 010306 general physics, Hamiltonian (quantum mechanics), Poisson algebra, Mathematical physics
Abstract

The Faddeev-Reshetikhin procedure corresponds to a removal of the non-ultralocality of the classical SU(2) principal chiral model. It is realized by defining another field theory, which has the same Lax pair and equations of motion but a different Poisson structure and Hamiltonian. Following earlier work of M. Semenov-Tian-Shansky and A. Sevostyanov, we show how it is possible to alleviate in a similar way the non-ultralocality of symmetric space sigma models. The equivalence of the equations of motion holds only at the level of the Pohlmeyer reduction of these models, which corresponds to symmetric space sine-Gordon models. This work therefore shows indirectly that symmetric space sine-Gordon models, defined by a gauged Wess-Zumino-Witten action with an integrable potential, have a mild non-ultralocality. The first step needed to construct an integrable discretization of these models is performed by determining the discrete analogue of the Poisson algebra of their Lax matrices., Comment: 31 pages; v2: minor changes

Published
2012
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20. Is the Rapid Decay Phase from High Latitude Emission?

Author

F. Genet, J. Granot, Charles Meegan, Chryssa Kouveliotou, Neil Gehrels, and School of Physics, Astronomy and Mathematics

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, Phase (waves), Single pulse, Flux, FOS: Physical sciences, Magnetic reconnection, Function (mathematics), Latitude, Pulse (physics), Computational physics, High latitude, Astrophysics - High Energy Astrophysical Phenomena
Abstract

"Copyright 2009 American Institute of Physics. This article may be downloaded for personal use only.Any other use requires prior permission of the author and the American Institute of Physics. Original paper can be found at: http://proceedings.aip.org/proceedings/ " DOI: 10.1063/1.3155933, There is good observationnal evidence that the Steep Decay Phase (SDP) that is observed in most Swift GRBs is the tail of the prompt emission. The most popular model to explain the SDP is Hight Latitude Emission (HLE). Many models for the prompt emission give rise to HLE, like the popular internal shocks (IS) model, but some models do not, such as sporadic magnetic reconnection events. Knowing if the SDP is consistent with HLE would thus help distinguish between different prompt emission models. In order to test this, we model the prompt emission (and its tail) as the sum of independent pulses (and their tails). A single pulse is modeled as emission arising from an ultra-relativistic thin spherical expanding shell. We obtain analytic expressions for the flux in the IS model with a Band function spectrum. We find that in this framework the observed spectrum is also a Band function, and naturally softens with time. The decay of the SDP is initially dominated by the tail of the last pulse, but other pulses can dominate later. Modeling several overlapping pulses as a single broader pulse would overestimates the SDP flux. One should thus be careful when testing the HLE., other

Published
2009
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21. New results on long secondary periods in red giants

Author

C. P. Nicholls, P. R. Wood, M.-R. L. Cioni, I. Soszyński, Joyce Ann Guzik, Paul A. Bradley, and School of Physics, Astronomy and Mathematics

Subjects
Physics, Oscillation, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Light curve, Giant star, Spectral line, Stars, Binary star, Astrophysics::Solar and Stellar Astrophysics, Circumstellar dust, Astrophysics::Earth and Planetary Astrophysics, Variable star, Astrophysics::Galaxy Astrophysics
Abstract

Original article can be found at: http://proceedings.aip.org/ Copyright 2009 American Institute of Physics. DOI: 10.1063/1.3246422 [Full text of this paper is not available in the UHRA], Approximately 30% of variable red giants have light curves which show a Long Secondary Period (LSP) in addition to their primary oscillation. No model has been proposed that can satisfactorily explain the LSPs. Here we present velocity curves obtained from VLT spectra for a large sample of LMC red giants exhibiting LSPs. We use the velocity data in addition to both MACHO and OGLE light curves to examine the properties of the stars, and to evaluate models for the cause of LSPs. Extant models generally involve either binarity or pulsation. We show that both of these have severe problems explaining the light and velocity variations. However, new mid-infrared observations of stars with LSPs indicate the presence of a significant amount of circumstellar dust, most likely in a disk-like configuration. This observation favours the presence of a binary companion., other

Published
2009
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22. Fundamental Properties of Low-Mass Stars and Brown Dwarfs

Author

Michael C. Liu, Keivan G. Stassun, France Allard, Cullen H. Blake, M. Bonnefoy, Ann Marie Cody, A. C. Day-Jones, Trent J. Dupuy, Adam Kraus, Mercedes López-Morales, Eric Stempels, Stempels, Eric, and School of Physics, Astronomy and Mathematics

Subjects
Physics, Initial mass function, media_common.quotation_subject, Astrophysics (astro-ph), Brown dwarf, FOS: Physical sciences, Astrophysics, Radius, Exoplanet, Characterization (materials science), Stars, Sky, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Low Mass, media_common
Abstract

Original paper can be found at: http://proceedings.aip.org/proceedings/confproceed/1094.jsp Copyright American Institute of Physics. DOI: 10.1063/1.3099100, Precise measurements of the fundamental properties of low-mass stars and brown dwarfs are key to understanding the physics underlying their formation and evolution. While there has been great progress over the last decade in studying the bulk spectrophotometric properties of low-mass objects, direct determination of their masses, radii, and temperatures have been very sparse. Thus, theoretical predictions of low-mass evolution and ultracool atmospheres remain to be rigorously tested. The situation is alarming given that such models are widely used, from the determination of the low-mass end of the initial mass function to the characterization of exoplanets.An increasing number of mass, radius, and age determinations are placing critical constraints on the physics of low-mass objects. A wide variety of approaches are being pursued, including eclipsing binary studies, astrometric-spectroscopic orbital solutions, interferometry, and characterization of benchmark systems. In parallel, many more systems suitable for concerted study are now being found, thanks to new capabilities spanning both the very widest (all-sky surveys) and very narrowest (diffraction-limited adaptive optics) areas of the sky. This Cool Stars 15 splinter session highlighted the current successes and limitations of this rapidly growing area of precision astrophysics., other

Published
2008

23. The Gamma Ray Burst section of the White Paper on the Status and Future of Very High Energy Gamma Ray Astronomy: A Brief Preliminary Report

Author

A. D. Falcone, D. A. Williams, M. G. Baring, R. Blandford, V. Connaughton, P. Coppi, C. Dermer, B. Dingus, C. Fryer, N. Gehrels, J. Granot, D. Horan, J. I. Katz, K. Kuehn, P. Mészáros, J. Norris, P. Saz Parkinson, A. Pe'er, E. Ramirez-Ruiz, S. Razzaque, X. Wang, B. Zhang, M. Galassi, David Palmer, Ed Fenimore, and School of Physics, Astronomy and Mathematics

Subjects
Physics, High energy, Opacity, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Cosmic ray, GRB 970417A, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Very high energy gamma ray astronomy, Afterglow, White paper, Preliminary report, Gamma-ray burst
Abstract

Original paper can be found at: http://proceedings.aip.org/proceedings/ Copyright American Institute of Physics DOI: 10.1063/1.2943545, other

Published
2008
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24. Modelling diffraction during ray-tracing using the concept of energy flow lines

Author

Evelyn Hesse, School of Physics, Astronomy and Mathematics, Centre for Atmospheric and Instrumentation Research, Science & Technology Research Institute, and Light Scattering & Radiactive Properties

Subjects
Diffraction, Physics, Radiation, Ice crystals, Geometrical optics, business.industry, Scattering, Physics::Optics, Atomic and Molecular Physics, and Optics, Magnetic field, Ray tracing (physics), Optics, Poynting vector, Projected area, business, Spectroscopy
Abstract

The ray tracing with diffraction on facets (RTDF) model is suitable for rapid computation of scattering on faceted dielectric objects such as ice crystals. It combines ray tracing with diffraction on flat facets. The model calculates diffraction using an approximation for the far field direction of the Poynting vector. In this paper an estimate based on an approximation by Prosser for the electric and magnetic fields describing diffraction at a slit is used to calculate energy flow lines and their far field deflection angle. Best-fit formulas describing the dependence of the far field deflection angle on the size parameter, angle of incidence, and the position of the flow line in the plane of the slit are derived and incorporated into the RTDF model. Phase functions for hexagonal columns are presented and compared with an analytic technique, the Separation of Variables Method, and Geometric Optics with projected area diffraction., Final Accepted Version

Published
2008
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25. ESA-ESO Working Group report \#4: ESA-ESO Working Group on Galactic Populations, Chemistry and Dynamics

Author

Turon, C., Primas, F., Binney, J., Chiappini, C., Drew, J., Helmi, A., Robin, A.C., Ryan, S.G., Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Leibniz-Institut für Astrophysik Potsdam (AIP), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Between the early 40s, when Baade showed the first evidence for the existence of two distinct stellar populations, and today, with our Galaxy surprising us with new substructures discovered almost on a monthly basis, it is clear that a remarkable progress has been achieved in our understanding of the Galaxy, of its structure and stellar populations, and of its chemical and dynamical signatures. Yet, some questions have remained open and have proven to be very challenging.The main task of this Working Group has been to review the state-of- the-art knowledge of the Milky Way galaxy, to identify the future challenges, and to propose which tools (in terms of facilities, infrastructures, instruments, science policies) would be needed to successfully tackle and solve the remaining open questions. Considering the leadership position that Europe has reached in the field of Galactic astronomy (thanks to the Hipparcos mission and the Very Large Telescope) and looking at the (near-) future major initiatives it has undertaken (VISTA and VST survey telescopes, Gaia mission), this work clearly has been very timely.It is of uttermost importance for European astronomy to keep and further consolidate its leading position. This Working Group has made recommendations that would allow dissecting our backyard laboratory, the Galaxy, even further. ESO survey telescopes about to become operational and the upcoming ESA Gaia mission are a guarantee for opening new horizons and making new discoveries. We, the astronomers, with the support of our funding agencies, are ready to fully commit to the best exploitation of the treasure that is ahead of us. The main recommendations this Working Group has made to ESA and ESO are to guarantee the expected tremendous capabilities of these new facilities, to vigourously organise their synergies and to jointly give ways to European astronomers to be leaders in the exploitation of their output data.

Published
2008

26. Submillimetre Astronomy with the James Clerk Maxwell Telescope

Author

G. Davis, A. Chrysostomou, and School of Physics, Astronomy and Mathematics

Subjects
Physics, Measure (physics), Astronomy, ComputingMilieux_LEGALASPECTSOFCOMPUTING, Astrophysics, Submillimetre astronomy, law.invention, ComputingMilieux_GENERAL, Telescope, law, Observatory, radiotelescopes, Instrumentation (computer programming), James Clerk Maxwell Telescope
Abstract

“This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.” DOI: 10.1109/MWSYM.2007.380112, other

Published
2007
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27. Molecules and Dust Grains in AGB Stars in Nearby Galaxies—the Influence of Metallicities

Author

M. Matsuura, A. A. Zijlstra, P. R. Wood, G. C. Sloan, M. A. T. Groenewegen, E. Lagadec, J. Th. van Loon, P. A. Whitelock, J. Bernard-Salas, J. W. Menzies, M.-R. L. Cioni, M. W. Feast, G. J. Harris, Richard J. Stancliffe, Guenter Houdek, Rebecca G. Martin, Christopher A. Tout, and School of Physics, Astronomy and Mathematics

Subjects
Physics, Stars, Spiral galaxy, Stellar mass, Asymptotic giant branch, Astronomy, Astrophysics, Large Magellanic Cloud, Giant star, Carbon star, Galaxy
Abstract

Original paper can be found at: http://scitation.aip.org/proceedings/confproceed/948.jsp Copyright AIP. DOI: 10.1063/1.2818993 [Full text of this paper is not available in the UHRA], We have obtained infrared spectra of carbon stars in four nearby galaxies—the Large and Small Magellanic Clouds, the Sagittarius dwarf spheroidal galaxy, and the Fornax dwarf spheroidal galaxy. Our primary aim is to investigate mass-loss rate and molecular bands of these stars as a function of metallicity, by comparing AGB stars in several galaxies with different metallicities. These stars were observed using the Infrared Spectrometer (IRS) onboard the Spitzer Space Telescope which covers 5–35 µm region, and the Infrared Spectrometer And Array Camera (ISAAC) on the Very Large Telescope which covers the 2.9–4.1 µm region. HCN, CH and C2H2 molecular bands, as well as SiC and MgS dust features are identified in the spectra. We find no evidence that mass-loss rates depend on metallicity. Carbon stars are strongly affected by carbon production during the AGB phase; primarily mass-loss of carbon-rich stars are driven by amorphous carbon dust grains, which explains the little metallicity dependence of mass-loss rate for carbon-rich stars. We found that C2H2 bands are prominent features at 3–15 µm among extragalactic carbon stars, which is not always the case for Galactic carbon stars. We argue that the difference is caused by systematically high C/O ratios in low-metallicity environments., other

Published
2007
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30. SCAMPS: the SCUBA Massive Precluster Survey

Author

Thompson, M.A., Gibb, A.G., Hatchell, J., Wyrowski, F., Pestalozzi, M., School of Physics, Astronomy and Mathematics, Science & Technology Research Institute, and Centre for Astrophysics Research

Abstract

other

Published
2005

31. Discovering Interacting Binaries with Halpha Surveys

Author

Janet E. Drew, Robert Greimel, Christian Knigge, Paul J. Groot, A. Witham, Quentin A. Parker, and School of Physics, Astronomy and Mathematics

Subjects
Physics, Astronomy, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics, Galactic plane, Schmidt camera, Wide field, Planetary nebula, Spectral line, Recovery rate, Emission spectrum, Focus (optics)
Abstract

A deep (R ~ 19.5) photographic Halpha Survey of the southern Galactic Plane was recently completed using the UK Schmidt Telescope at the AAO. In addition, we have recently started a similar, CCD-based survey of the northern Galactic Plane using the Wide Field Camera on the INT. Both surveys aim to provide information on many types of emission line objects, such as planetary nebulae, luminous blue variables and interacting binaries. Here, we focus specifically on the ability of Halpha emission line surveys to discover cataclysmic variables (CVs). Follow-up observations have already begun, and we present initial spectra of a candidate CV discovered by these surveys. We also present results from analyzing the properties of known CVs in the Southern Survey. By calculating the recovery rate of these objects, we estimate the efficiency of Halpha-based searches in finding CVs., Comment: 4 pages, 3 figures. To appear in the proceedings of the conference Interacting Binaries in Cefalu, 2004

Published
2005

32. A dual-wavelength single particle aerosol fluorescence monitor

Author

Warren Stanley, Paul H. Kaye, Virginia Foot, Karen L. Baxter, Stephen J. Barrington, School of Physics, Astronomy and Mathematics, Science & Technology Research Institute, Centre for Atmospheric and Instrumentation Research, and Particle Instrumentation

Subjects
business.industry, Chemistry, Laser, Fluorescence, Light scattering, Biological materials, law.invention, Aerosol, Bio aerosol, Optics, law, Particle, Optoelectronics, Dual wavelength, business
Abstract

Original article can be found at: http://spie.org/x306.xml Copyright SPIE DOI: 10.1117/12.629868 [Full text of this article is not available in the UHRA], Laser diodes and light-emitting diodes capable of continuous sub-300 nm radiation emission will ultimately represent optimal excitation sources for compact and fieldable bio-aerosol monitors. However, until such devices are routinely available and whilst solid-state UV lasers remain relatively expensive, other low-cost sources of UV can offer advantages. This paper describes one such prototype that employs compact xenon discharge UV sources to excite intrinsic fluorescence from individual particles within an ambient aerosol sample. The prototype monitor samples ambient air via a laminar sheathed-flow arrangement such that particles within the sample flow column are rendered in single file as they intersect the beam from a continuous-wave 660nm diode laser. Each individual particle produces a scattered light signal from which an estimate of particle size (down to ~1 um) may be derived. This same signal also initiates the sequential firing (~10 us apart) of two xenon sources which irradiate the particle with UV pulses centred upon ~280 nm and ~370 nm wavelength, optimal for excitation of bio-fluorophores tryptophan and NADH respectively. For each excitation wavelength, fluorescence is detected across two bands embracing the peak emissions of the same bio-fluorophores. Thus, for each particle, a 2-dimensional fluorescence excitation-emission matrix is recorded together with an estimate of particle size. Current measurement rates are up to ~125 particles/s (limited by the xenon recharge time), corresponding to all particles for concentrations up to ~2 x 10^4 particles/l. Developments to increase this to ~500 particles/s are in hand. Analysis of results from aerosols of E.coli, BG spores, and a variety of non-biological materials are given.

Published
2005
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33. Stellar and Gas Kinematics in the core and bar regions of M100

Author

E. L. Allard, Johan H. Knapen, Reynier Peletier, and School of Physics, Astronomy and Mathematics

Subjects
Physics, Stars, Barred spiral galaxy, Spiral galaxy, Star formation, Elliptical galaxy, Astronomy, Velocity dispersion, Astrophysics::Cosmology and Extragalactic Astrophysics, Kinematics, Astrophysics, Astrophysics::Galaxy Astrophysics, Galaxy
Abstract

Original paper can be found at http://www.virtualjournals.org/proceedings/confproceed/783.jsp Copyright American Institute of Physics. DOI: 10.1063/1.2034969 [Full text of this article is not available in the UHRA], Two-dimensional maps of the stellar and gas kinematics of the bar and starbursting circumnuclear region in the barred spiral galaxy M100 are presented. In this progress report, we present maps of the total intensity, mean velocity and velocity dispersion for the stars and the gas. The gas velocity field shows significant kinematic signatures of gas streaming along the inner part of the bar, and across the miniature spiral arms in the nuclear pseudo-ring. The stellar velocity field, presented here for the first time, also shows non-circular motions. The gas velocity dispersion is notably smaller where the star formation occurs in the nuclear zone and HII regions. We outline our further plans with the data set., other

Published
2005
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34. The Halo Lithium Plateau: Outstanding Issues

Author

Ryan, Sean G., Elliott, L., and School of Physics, Astronomy and Mathematics

Subjects
endocrine system, urogenital system, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We examine outstanding issues in the analysis and interpretation of the halo Li plateau. We show that the majority of very Li-poor halo Li-plateau stars (5 out of 8) have high projected rotation velocities vsini between 4.7 and 10.4 km s^-1. Such stars have very different evolutionary histories to Li-normal plateau stars, and hence cannot be included in studies of Li depletion by normal halo dwarfs. Uncertainties in the effective temperature scale for metal-poor stars continue to challenge the analysis of Li., 6 pages, 1 table to appear in the Proceedings of the ESO/Arcetri Conference on Chemical Abundances and Mixing in Stars in the Milky Way and its Satellites, edited by Luca Pasquini and Sofia Randich, published by Springer-Verlag as part of the "ESO Astrophysics Symposia"

Published
2004

35. A large area search for radio-loud quasars within the epoch of reionization

Author

Jarvis, MJ, Rawlings, S, Barrio, FE, Hill, GJ, Bauer, A, Croft, S, Mújica, R, Maiolino, R, Mújica, R, Maiolino, R, and School of Physics, Astronomy and Mathematics

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Quasar, Observable, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Redshift, Galaxy formation and evolution, Reionization, Molecular absorption, Astrophysics::Galaxy Astrophysics
Abstract

Original paper can be found at: http://eproceedings.worldscinet.com/9789812702432/toc.shtml Copyright World Scientific Publishing Co. Pte. Ltd. DOI : 10.1142/9789812702432_0034, other

Published
2004

36. Some Recent Peculiarities of the Early Afterglow

Author

Jonathan Granot, Ehud Nakar, Tsvi Piran, and School of Physics, Astronomy and Mathematics

Subjects
Physics, Astrophysics (astro-ph), GRB 030329, FOS: Physical sciences, Astrophysics, Gamma-ray burst, Light curve, Afterglow
Abstract

We consider some recent developments in GRB/afterglow observations: (i) the appearance of a very hard prompt component in GRB 941017, and (ii) variability in the early afterglow light curves of GRB 021004 and GRB 030329. We show that these observations fit nicely within the internal-external shocks model. The observed variability indicates that the activity of the inner engine is more complicated than was thought earlier and that it involves patchy shells and refreshed shocks. We refute the claims of Berger et al. and of Sheth et al. that the radio and mm observations of GRB 030329 are inconsistent with refreshed shocks., Comment: 6 pages; Talk given by Tsvi Piran at the Gamma-Ray Burst Symposium, Santa Fe, NM 8-12 Spet 2003

Published
2004
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37. Single-Particle Raman Spectrometer (SPaRS) for the non-destructive physico-chemical characterisation of aerosols

Author

Richard Greenaway, Dalley, J. E. J., Zbigniew Ulanowski, Evelyn Hesse, Paul Kaye, and School of Physics, Astronomy and Mathematics

Abstract

This project seeks to develop a prototype systems for the analysis of single levitated micrometre-sized particles captured from an ambient aerosol. The systems is designed to use Raman scattering to establish chemical nature of the particle, whilst simultaneously recording spatial elastic light scattering data from which an assessment of particle size, shape and physical structure may be acieved.Thismulti-parametric approach should provide a means of discriminating atmospheric particles whose toxitcity is determined by morphology as well as chemical composition. Areas of application could include environmental monitoring, source apportionment, occupational air quality investigation and potentially as part of a strategy for bio-aerosol detection, other

Published
2004

39. Numerical Simulation of Photochemical Episodes in Alpine Valleys

Author

Brulfert, G., Chollet, J.P., Chemel, C., Kerbiriou, M.A., and School of Physics, Astronomy and Mathematics

Subjects
ComputingMilieux_GENERAL, GeneralLiterature_INTRODUCTORYANDSURVEY, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, ComputingMilieux_LEGALASPECTSOFCOMPUTING, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract

“The original publication is available at www.springerlink.com”. Copyright Springer, other

Published
2004

41. Heavy Elements in DA White Dwarfs

Author

Barstow, M.A., Burleigh, M.R., Bannister, N.P., Holberg, J.B., Hubeny, I., Bruhweiler, F.C., Napiwotzki, R., and School of Physics, Astronomy and Mathematics

Abstract

other

Published
2001

42. The ages of circumnuclear starbursts from Near-IR spectroscopy: Bushfires or Mexican Wave

Author

Ryder, S.D., Knapen, J., Alonso-Herrero, A., Takamiya, M., and School of Physics, Astronomy and Mathematics

Subjects
ComputingMilieux_GENERAL, ComputingMilieux_THECOMPUTINGPROFESSION, ComputerApplications_COMPUTERSINOTHERSYSTEMS, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract

Original paper can be found at http://www.astrosociety.org/pubs/cs/222-252.html--Copyright Astronomical Society of the Pacific, We have pbtained K-band spectra with CGS4 on UKIRT for circumnuclear star-forming regions in NGC 4321, NGC 2903 and NGC 7469. A comparison of the equivalent widths of Bry emission and CO absorption with starburst models in the literature allows us to simultaneously determine the age distribution and burst decay timescales around each ring. We find that the majority of the star-forming regions are rapidly decaying bursts with ages between 8 and 10 million years, but that only NGC 4321 displays a clear age sequence. We discuss the implications of these results for the triggering and evolution of circumnuclear star formation., other

Published
2001

44. Optimization of frequency domain measurement technique and development of a clinical prototype optical tomography system

Author

R. Khalaf, P. van der Zee, Warren Stanley, and School of Physics, Astronomy and Mathematics

Subjects
medicine.diagnostic_test, Computer science, business.industry, Image quality, Computation, Detector, Iterative reconstruction, Multiplexing, Optics, Frequency domain, Electronic engineering, Medical imaging, medicine, Optical tomography, business
Abstract

other

Published
2000

45. Hydrodynamics and Radiation from a Relativistic Expanding Jet with Applications to GRB Afterglow

Author

Tsvi Piran, Jonathan Granot, Mark A. Miller, Wai-Mo Suen, and School of Physics, Astronomy and Mathematics

Subjects
Physics, Jet (fluid), Astrophysics::High Energy Astrophysical Phenomena, Resolution (electron density), Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics, Radiation, Light curve, Spectral line, Synchrotron, Computational physics, Afterglow, law.invention, law, Gamma-ray burst
Abstract

We describe fully relativistic three dimensional calculations of the slowing down and spreading of a relativistic jet by an external medium like the ISM. We calculate the synchrotron spectra and light curves using the conditions determined by the hydrodynamic calculations. Preliminary results with a moderate resolution are presented here. Higher resolution calculations are in progress., Comment: To appear in the proceedings of the 5th Huntsville Symposium on Gamma Ray Bursts

Published
1999
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46. Polarimetry for the Gemini telescopes

Author

Antonio Chrysostomou, David K. Aitken, J. H. Hough, and School of Physics, Astronomy and Mathematics

Subjects
Gemini Observatory, Physics, Polarimetry, Astronomy, Astrophysics
Abstract

Original paper is available at: http://scitation.aip.org/journals/doc/SPIEDL-home/proc/ Copyright SPIE. DOI: 10.1117/12.317221 [Full text of this paper is not available in the UHRA], Polarimeters at optical and near-IR wavelengths are increasingly available as part of facility instruments at major observatories, and are used for a large number of astronomical programs, ranging form nearby star-forming regions to high-redshift galaxies. Polarimetry is used in both imaging and spectroscopic modes and at both low and high spectral resolutions. As degrees of polarization are usually low a large collecting area is needed to get the high signal to noise required for accurate polarimetry. Thus polarimetry can take particular advantage of the new generation 8m telescopes such as Gemini. Techniques for obtaining high precision measurements used for IR polarimeters on UKIRT and on the AAT, together with the performance achieved for both imagers and spectrometers are presented. The implementation of the same techniques proposed for Gemini instruments is described., other

Published
1998
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47. H IIRegion Statistics in Barred and Non-Barred Galaxies

Author

Rozas, M., Beckman, J.E., Knapen, J., and School of Physics, Astronomy and Mathematics

Subjects
ComputingMilieux_GENERAL, ComputingMilieux_THECOMPUTINGPROFESSION, ComputerApplications_COMPUTERSINOTHERSYSTEMS, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract

Original paper can be found at: http://www.astrosociety.org/pubs/cs/070-112.html--Copyright Astronomical Society of the Pacific, We present new high quality Ha continuum-subtracted images of the grand design galaxies NGC 157, NGC 3631, NGC 6764, and NGC 6951, two of them barred and two non-barred, and describe the statistical properties of the HII regions. We have determined the positions, angular sizes and fluxes of individual HII regions, and construct luminosity functions and diameter and density distributions. We find no significant differences between arm and interarm HII region properties, or between the barred and non-barred galaxies. This paper summarizes work described in more detail by Rozas et al (1995)., other

Published
1996

48. Star and globular cluster formation in mergers

Author

Fritze, U. and School of Physics, Astronomy and Mathematics

Abstract

Copyright Kluwer / International Astronomical Union [Full text of this paper is not available in the UHRA], other

Published
1996

49. Massive stars shaping the ISM:Hi holes and shells in nearby galaxies

Author

Elias Brinks, Walter, F., and School of Physics, Astronomy and Mathematics

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Neutral hydrogen (H I) is a magnificent tool when studying the structure of the interstellar medium (ISM) as it is relatively easily observable and can be mapped at good spatial and velocity resolution with modern instruments. Moreover, it traces the cool (~ 100 K) and warm (~ 5000 K) neutral gas which together make up about 60%, or the bulk, of the ISM. The currently accepted picture is that stellar winds and subsequent supernovae are the origin for the clearly defined holes or bubbles within the more or less smooth neutral medium. The H I can therefore serve indirectly as a tracer of the hot interstellar medium (HIM)left behind after the most massive stars within an OB association have gone off as supernovae. A splendid example is the dwarf galaxy IC 2574 for which we discuss H I, optical and X-ray observations., other

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