SOHO 18/GONG 2006/HELAS I Beyond the spherical Sun

Transcription

1 SP-624 October 2006 SOHO 18/GONG 2006/HELAS I Beyond the spherical Sun 7-11 August 2006 Sheffield, UK

2 Scientific Organising Committee Michael Thompson (Chair) University of Sheffield, UK Bo Andersen Norwegian Space Centre, Norway Annie Baglin Observatoire de Paris-Meudon, France Sarbani Basu Yale University, USA Paul Cally Monash University, Australia Yvonne Elsworth University of Birmingham, UK Bernhard Fleck ESA Space Science Department, USA Douglas Gough University of Cambridge, UK Hans Kjeldsen Aarhus University, Denmark Don Kurtz University of Central Lancashire, UK John Leibacher National Solar Observatory, USA Pere Pallé Instituto de Astrofisica de Canarias, Spain Phil Scherrer Stanford University, USA Hiromoto Shibahashi University of Tokyo, Japan Sylvaine Turck-Chièze Service d Astrophysique / DAPNIA, France Local Organising Committee Michael Thompson (Chair) University of Sheffield Robert Erdélyi University of Sheffield Rekha Jain University of Sheffield Roger New Sheffield Hallam University Publication: Proceedings, SOHO 18/GONG 2006/HELAS I Beyond the spherical Sun Noordwijk, The Netherlands (ESA SP-624, October 2006) Editor: Karen Fletcher Scientific Editor: Michael Thompson Published and distributed by: ESA Publications Division ESTEC Postbus AG Noordwijk The Netherlands Tel: Fax: Printed in: The Netherlands Price: 60 ISBN: ISSN: Copyright: 2006 European Space Agency

3 CONTENTS Introduction and welcome Chair: B Fleck Various dynamical puzzle pieces in the seismic Rubik s cube J Toomre Local helioseismology: techniques and issues A C Birch Session 1 Local methodologies Chair: B Fleck Farside helioseismic holography: recent advances I González Hernández, F Hill, C Lindsey, D Braun, P Scherrer, S M Hanasoge Magnetoseismic signatures of active regions and the question of rapid downflows beneath sunspots C Lindsey Observed and simulated photospheric velocities within inclined magnetic fields H Schunker, P Cally Session 2 Temporal variations and flows Chair: M Roth Seismic results on temporal variation of the solar interior R Howe Toward improving the seismic visibility of the solar tachocline S M Jefferies, S V Vorontsov, C Giebink The seismic Sun over three activity cycles W J Chaplin, Y Elsworth, S J Hale, B A Miller, G A Verner, R New Cyclic variability of the seismic solar radius from SOHO/MDI and related physics S Lefebvre, A G Kosovichev, P Nghiem, S Turck-Chièze, and J P Rozelot Interior structures and flows beneath sunspots from time-distance helioseismology J Zhao Subsurface convective flows within active regions B W Hindman, D A Haber, J Toomre

4 Session 2 (continued) Chair: P Cally Consequences of large-scale flows around active regions on the dispersal of magnetic field across the solar surface M L DeRosa, C J Schrijver Effect of the subsurface shear layer on solar supergranulation C A Green, A G Kosovichev, M S Miesch Effect of sunspot structure from p-modes scattering M Gordovskyy, R Jain, M J Thompson Magnetic seismology of the lower solar atmosphere R Erdélyi Session 3 Seismology above the photosphere Chair: P Cally Low-frequency magneto-acoustic waves in the solar chromosphere S M Jefferies, S W McIntosh, J D Armstrong, T J Bogdan, A Cacciani, B Fleck Session 4 Modelling the solar interior Chair: R Komm Reconciling the revised solar abundances with helioseismic constraints J A Guzik Non-kinematic flux-transport dynamos and torsional oscillations M Rempel Solar evolution model with diffusion and new equation of state S V Ayukov, V A Baturin, A B Gorshkov Molecular-dynamics simulations of hot dense Coulomb systems K Mussack, D Mao, W Däppen Session 5 Low-degree seismology from the Sun to the stars Chair: D O Gough Helioseismology with low-degree observations: where we stand, and what the future holds W J Chaplin The internal structure of the Sun inferred from g modes and low-frequency p modes Y P Elsworth et al.

5 Detection of periodic signatures in the solar power spectrum On the track of l=1 gravity modes R A García, S Turck-Chièze, S J Jiménez-Reyes, J Ballot, P L Pallé, A Eff-Darwich, S Mathur, J Provost The DynaMICS perspective S Turck-Chièze et al. Observations of solar-like oscillations T Bedding, H Kjeldsen Rigorous analysis of dipolar oscillations of stars M Takata Frequency, splitting, linewidth and amplitude estimates of low-l p modes of alpha Cen A: analysis of WIRE photometry S T Fletcher, W J Chaplin, Y Elsworth, J Schou, D Buzasi Session 6 Mode physics Chair: H Kjeldsen Stochastic excitation and damping of solar-like oscillations G Houdek Energetic effects in classical pulsators M-A Dupret, A Grigahcène, S Théado, P-O Bourge, M Gabriel Session 7 A new era of asteroseismlogy Chair: H Kjeldsen Studying solar-like oscillations in red giants: MOST spacebased photometry of epsilon Ophiuchi C Barban et al. Modelling intermediate mass red giants O Moreira, A Noels, M-A Dupret Session 7 (continued) Chair: S Basu Asteroseismology of hot B subdwarf stars: a brief overview G Fontaine, P Brassard, S Charpinet, E M Green, P Chayer, S Randall, B Dorman Observations of magneto-acoustic modes in strongly magnetic pulsating roap stars D W Kurtz, V G Elkin, G Mathys The seismology programme of the CoRoT space mission A Baglin, E Michel, M Auvergne, and the CoRoT team

6 Asteroseismology of exoplanets-host stars S Vauclair Session 8 Dynamics and numerical simulation Chair: F Hill Dynamical processes in stellar radiation zones: secular magnetohydrodynamics of rotating stars S Mathis, T Decressin, A Palacios, L Siess, C Charbonnel, S Turck-Chièze, J-P Zahn Internal gravity waves in the Sun S Talon Dynamical processes in the solar radiative interior A Palacios, S Talon, S Turck-Chièze, C Charbonnel Suppression of amplitude of 5-min oscillations in sunspots due to the lack of acoustic sources K Parchevsky, A Kosovichev Solar acoustic simulator S M Hanasoge, T L Duvall Prospects for helio- and asteroseismology J Christensen-Dalsgaard Poster Papers P1 P2 P3 P4 P6 P8 P10 P11 Optimal phase-speed filters in time-distance helioseismology S Couvidat, A C Birch Sensitivity kernels for helioseismic travel times in spherical geometry preliminary results M Roth, L Gizon, A C Birch Acoustic scattering by flux tubes: is the Born approximation valid? L Gizon, S M Hanasoge, A C Birch Large-scale circulations using ring analysis D Haber, B Hindman, J Toomre, R S Bogart The group velocity of solar p modes S V Vorontsov Temporal variations of travel-time differences from GONG++ S Kholikov, J Leibacher Correcting Dopplergrams for solar active regions: consequences for local helioseismology R Wachter, S P Rajaguru, R S Bogart Effects of horizontal magnetic fields on acoustic travel-times R Jain

7 P12 P13 P14 P15 P16 P18 P22 P23 P24 P25 P26 P27 P28 P29 P30 P31 Dynamics study of solar oscillations and granulation with THÉMIS observations R Simoniello, S J Jiménez Reyes Inferring subsurface supergranular flow directly from helioseismic correlation data M F Woodard f-mode sensitivity kernels for flows J Jackiewicz, L Gizon, A Birch Subsurface flows measured with big rings R Komm, I González Hernández, R Howe, F Hill Subsurface flows from numerical simulations compared with flows from ring analysis S Ustyugov, R Komm, O Burtseva, R Howe, S Kholikov B0-angle effect on zonal and meridional flow determinations from 3 years ring diagram analysis of GONG++ data A Zaatri, R Komm, I González Hernández, R Howe, T Corbard Solar rotation and zonal flows from Mount Wilson 60 ft tower data R Howe, R Bogart, J Christensen-Dalsgaard, E J Rhodes Jr, P Rose, J Schou Meridional flow measurements with statistical waveform analysis U Mitra-Kraev, M J Thompson, M F Woodard Examining possible errors in the inversion results of active regions through a model study C-H Lin, L Li, S Basu Acoustic power and magnetic field orientation in a large sunspot S Gosain, P Venkatakrishnan, K Venugopalan The cookie cutter test for time-distance tomography of active regions S G Korzennik Comparative study of isolated sunspots using time-distance helioseismology S Zharkov, C J Nicholas, M J Thompson Subsurface structure evolution associated with the rise and fall of intensely active regions R S Bogart, S Basu, M C Rabello-Soares, H M Antia Three-dimensional numerical simulation of wave propagation through a model sunspot R Cameron, L Gizon Magnetic field inclination and atmospheric oscillations above solar active regions: theory P S Cally, H Schunker On the enhanced velocity oscillations observed during solar flares B Kumar, P Venkatakrishnan, K Venugopalan P33 The acoustically active solar flare of 2005 January 15 H Moradi, A-C Donea, C Lindsey, D Besliu-Ionescu, P S Cally

8 P34 P35 P36 P37 P38 P39 P40 P41 P42 P43 P44 P45 P46 P47 P48 P49 P50 Seismic emission from M-class solar flares D Besliu-Ionescu, A-C Donea, P Cally, C Lindsey Peak parameter shifts from large-aperture ring diagram analysis R Howe, I González Hernández, F Hill, R Komm Phenomenological simulation of the total solar irradiance and its power spectrum H Vázquez Ramió, C Régulo, T Roca Cortés Solar mean magnetic field near the surface and its variation during a cycle P A P Nghiem, R A García, S J Jiménez-Reyes High-degree mode frequencies: changes with solar cycle M C Rabello-Soares, S G Korzennik, J Schou Helioseismic modes in a magnetic atmospheric solar model B Pintér, R Erdélyi Hydrodynamic evolution of the solar tachocline S Talon How magnetic is the solar tachocline? R Arlt, A Sule, G Rüdiger MHD turbulence on a ß-plane N Leprovost, E-J Kim Turbulent transport in the solar interior E-J Kim, N Leprovost Convection and non-axisymmetric large-scale flows at the base of the solar convection zone E Tikhomolov A non-local MLT treatment fitting 3D simulations M-A Dupret, M-J Goupil, R Samadi, A Grigahcène, M Gabriel Supergranule scale convection simulations R F Stein, D Benson, D Georgobiani, Å Nordlund Seismic estimate of solar heavy element abundances S Basu, H M Antia A seismic solar model with the updated elemental abundances H Shibahashi, S Tamura Rotation inversions of artificial solarflag Sun-as-a-star data W J Chaplin et al. Coupling of high-degree solar p modes by differential rotation S V Vorontsov

9 P51 P52 P53 P54 P55 P56 P57 P58 P59 P61 On the direct determination of sensitivity, resolution and information content of helioseismic data application to the inversion of the solar core rotation rate A Eff-Darwich, S G Korzennik, S J Jiménez-Reyes, R A García Evolutionary convective envelope in modern model of the Sun V A Baturin A new method to estimate the acoustic cut-off frequency of the Sun using the different properties between p-modes and pseudomodes of low degree A Jiménez, S J Jiménez-Reyes, R A García Examining the effect of the new chemical composition on solar structure by using the adiabatic index C-H Lin, H M Antia, S Basu On seismic signatures of rapid variation G Houdek, D O Gough How GOLF sees the second helium ionization layer across the solar cycle J Ballot, S J Jiménez-Reyes, R A García Solar-cycle variations in p-mode frequencies and even-order splitting coefficients from LOWL observations D Salabert, S J Jiménez-Reyes Are the shapes of the p-mode peaks distorted by the solar cycle when they are observed in long, multi-year power frequency spectra? W J Chaplin, Y Elsworth, R New, T Toutain How does the change on solar abundances affect low degree modes? A Zaatri, J Provost, G Berthomieu, P Morel, T Corbard Changes to global mode parameters over a solar cycle S C Tripathy, F Hill, K Jain, J W Leibacher P62 Comparison of the solar velocity spectrum from MDI and GOLF during cycle 23 S Lefebvre, R A García, S J Jiménez-Reyes, S Turck-Chièze P63 P64 P65 P66 Sensitivity of the predicted frequencies of l = 1 gravity modes to known physical processes S Mathur, S Turck-Chièze, S Couvidat, R A Garcia Needles in haystacks: how to use contemporaneous data in the search for g-modes A M Broomhall, W J Chaplin, Y Elsworth Theoretical damping rates and phase-lags for solar-like oscillations M A Dupret, C Barban, M-J Goupil, R Samadi, A Grigahcène, M Gabriel Solar-activity changes in the p-mode damping and excitation observed in LOWL data D Salabert, S J Jiménez-Reyes

10 P68 P69 P70 P71 P72 P73 P75 P76 P78 P79 P80 P81 P82 P83 P84 P85 P86 BiSON update J Allison et al. Analysis of velocity-noise variations arising from photon-noise in data from the GOLF instrument R New, W J Chaplin, Y P Elsworth, R A García, S J Jiménez-Reyes Reliable analysis of power and phase features as seen from BiSON and GOLF observations R Simoniello, Y P Elsworth, W J Chaplin, R García Comparison of solar p-mode lifetimes from GONG, MDI and TON data O Burtseva, S Kholikov, F Hill, J Bolding, O Ladenkov, D-Y Chou A comparison of acoustic mode parameters using multi-spectral data K Jain et al. Comparison of local frequency shifts between MDI velocity and intensity data S C Tripathy, H M Antia, F Hill, K Jain, I González Hernández et al. High resolution spectrum: towards a new observational strategy N Seghouani Study of the role of phase evolution in the amplitudes of low-degree solar p-modes R Simoniello, W J Chaplin, Y Elsworth, R New The effects of rotation on frequency of stellar oscillations K D Burke, M J Thompson On the possible existence of localised vacillating convection state in rapidly rotating young solarlike stars J Ballot, A S Brun, S Turck-Chièze Asteroseismic diagnostics of stellar convective cores A Mazumdar, S Basu, B L Collier, P Demarque Kepler telescope and solar-like pulsators J Molenda-Zakowicz, T Arentoft, H Kjeldsen, A Bonanno Calibrating the solar dynamo: magnetic activity cycles of southern Sun-like stars T S Metcalfe, T J Henry, M Knölker, D R Soderblom On the prospects for sounding activity cycles on Sun-like stars W J Chaplin, Y Elsworth, G Houdek, R New Evidence for degree dependence of changes in p-mode damping along the solar cycle in Sun-as-astar data D Salabert, W J Chaplin, Y Elsworth, R New, G A Verner The complementary roles of interferometry and asteroseismology O L Creevey, M J P F G Monteiro, T S Metcalfe, T M Brown 12 Bootis: the need for asteroseismic constraints A Miglio, J Montalbán, C Maceroni, J De Ridder, F D Antona

11 P87 P89 P90 P91 P92 P93 P95 P97 Procyon-A and Bootis: observational frequencies analyzed by the local-wave formalism P A P Nghiem, J Ballot, R A García, P Lambert, S Turck-Chièze A line profile analysis of the pulsating red giant star Ophiuchi (G9.5III) S Hekker, C Aerts, J De Ridder, F Carrier Asteroseismology of K giants M P Di Mauro et al. Pulsational properties of the Cephei star SY Equ from combined photometric and spectroscopic observations J Daszynska-Daszkiewicz, A Pigulski Chemical composition of the pulsating Cephei star Peg E Niemczura, G Polubek SIAMOIS: an asteroseismic network with 1 site in Antarctica M Benoît and the SIAMOIS team The spectral resolving power of irregularly sampled time series F Pijpers Helioseismology of sub-photospheric flows S Shelyag, R Erdélyi, M J Thompson P101 Forward modeling of atmospheric magneto-acoustic-gravity waves J D Armstrong P102 The parameters of seismic sources in the flare of 28 October 2003 V V Zharkova, S I Zharkov P103 g-mode search and the solar cycle A Gabriel P104 Does the inference of solar subsurface flow change with choice of the spectral line? K Jain, F Hill, I González Hernández, C G Toner, S C Tripathy, J D Armstrong, S M Jefferies P105 Temporal variations of solar rotation during solar cycle 23 S Basu, H M Antia P106 P109 Time-varying component of the solar meridional flow L Gizon, M Rempel European helio- and asteroseismology network HELAS M Roth et al. P110 Propagation of p-modes into the solar atmosphere * Y Taroyan, R Erdélyi, C Malins * Please note this paper is not listed in the contents of the Proceedings, but the paper is present on the CD.

12 Late papers The pulsations and potential for seismology of B stars C Aerts Distribution of MDI p-mode power correlation coefficients H Y Chang, T Sekii Helioseismic probing of giant-cell convection N A Featherstone, D A Haber, B W Hindman, J Toomre Sunquake sources and wave propagation A G Kosovichev