J/ApJ/774/6ivo://CDS.VizieR/J/ApJ/774/6doi:10.26093/cds/vizier.17740006CDSYadav R.K.Gastine T.Christensen U.R.Duarte L.D.V.2018-02-02T10:34:12Z2015-03-23T14:15:29ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frastronomical-modelsmagnetic-fieldsNumerical dynamo models always employ parameter values that differ by orders of magnitude from the values expected in natural objects. However, such models have been successful in qualitatively reproducing properties of planetary and stellar dynamos. This qualitative agreement fuels the idea that both numerical models and astrophysical objects may operate in the same asymptotic regime of dynamics. This can be tested by exploring the scaling behavior of the models. For convection-driven incompressible spherical shell dynamos with constant material properties, scaling laws had been established previously that relate flow velocity and magnetic field strength to the available power. Here we analyze 273 direct numerical simulations using the anelastic approximation, involving also cases with radius-dependent magnetic, thermal, and viscous diffusivities. These better represent conditions in gas giant planets and low-mass stars compared to Boussinesq models. Our study provides strong support for the hypothesis that both mean velocity and mean magnetic field strength scale as a function of the power generated by buoyancy forces in the same way for a wide range of conditions.2013ApJ...774....6Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/774/6CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/774/6https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/774/6http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/774/6https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/774/6https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/774/6http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/774/6GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/774/6/table1Simulation setupsBCMechanical boundary condition (1)meta.codecharN[1/58] Number of casesmeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSIDSubset name (A=Anelastic; B=Boussinesq)meta.idcharprimaryCoreCore description ("Insulating" or "Conducting")stat.paramchareta[0.1/0.8] Aspect ratio {eta} (inner radius to outer radius ratio of shell with dynamo action)phys.size;arith.ratiofloatg(r)Gravity profile g(r) (2)stat.paramm[0/2] Polytropic index m (2)stat.paramfloatPrPrandtl number P_r_ rangestat.paramcharPmMagnetic Prandtl number P_m_ range (ratio of viscosity {nu} and thermal diffusivity {kappa})stat.paramcharEEkman number E (or lower range)stat.paramfloatE2? Ekman number (upper range)stat.paramfloatnullableNrhoNumber of density scale heights inside the shell N_{rho}_stat.paramcharVarVarying inside the shell (3)meta.noteJ/ApJ/774/6/table2Simulation dataset used in the article to infer various scaling lawsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSIDSimulation identifier (as in table 1)meta.idcharEEkman number E={nu}/({Omega}D^2^)stat.paramdoublePr[0/10] Prandtl number P_r_={nu}/{kappa}stat.paramfloatPm[0/20] Magnetic Prandtl number P_m_={nu}/{lambda}stat.paramfloatRaRayleigh number R_a_stat.fit.paramdoubleNrho[0/5.5] Number of density scale heights N_{rho}_meta.numberfloatMass[8/630] Non-dimensional mass of spherical shellphys.massdoublechim[0.7/1]? Fraction of total radius (1)phys.size.radius;arith.ratiofloatnullableP[2.e-8/3.e-2] Non-dimensional buoyancy power (2)stat.paramdoubleRo[0.001/0.44] Rossby number defined by Eq.13stat.paramdoubleRoconv[0.001/0.3] Rossby number (3)stat.paramdoubleLo[0/0.1] Lorentz number defined by Eq.14stat.paramdoublefohm[0/0.7] Ohmic fraction defined by Eq.17stat.fit.paramdoubletaumag[0.7/135] Magnetic dissipation time {tau}_mag_ defined by Eq.18time.intervaldoublefdipDipolarity (4)stat.paramdouble