Results from a set of three-dimensional numerical experiments of a hot Jupiter atmosphere

We present highlights from a large set of simulations of a hot Jupiter atmosphere, nominally based on HD 209458b, aimed at exploring both the evolution of the deep atmosphere, and the acceleration of the zonal flow or jet. We find the occurrence of a super-rotating equatorial jet is robust to changes in various parameters, and over long timescales, even in the absence of strong inner or bottom boundary drag. This jet is diminished in one simulation only, where we strongly force the deep atmosphere equator-to-pole temperature gradient over long timescales. Finally, although the eddy momentum fluxes in our atmosphere show similarities with the proposed mechanism for accelerating jets on tidally-locked planets, the picture appears more complex. We present tentative evidence for a jet driven by a combination of eddy momentum transport and mean flow.Comment: 26 pages, 22 Figures. Accepted for publication in Astronomy and Astrophysic

Parallaxes and Infrared Photometry of three Y0 dwarfs

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2017 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.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.Peer reviewe

Radiation of Neutron Stars Produced by Superfluid Core

We find that neutron star interior is transparent for collisionless electron sound, the same way as it is transparent for neutrinos. In the presence of magnetic field the electron sound is coupled with electromagnetic radiation and form the fast magnetosonic wave. We find that electron sound is generated by superfluid vortices in the stellar core. Thermally excited helical vortex waves produce fast magnetosonic waves in the stellar crust which propagate toward the surface and transform into outgoing electromagnetic radiation. The vortex radiation has the spectral index -0.45 and can explain nonthermal radiation of middle-aged pulsars observed in the infrared, optical and hard X-ray bands. The radiation is produced in the stellar interior which allows direct determination of the core temperature. Comparing the theory with available spectra observations we find that the core temperature of the Vela pulsar is T=8*10^8K, while the core temperature of PSR B0656+14 and Geminga exceeds 2*10^8K. This is the first measurement of the temperature of a neutron star core. The temperature estimate rules out equation of states incorporating Bose condensations of pions or kaons and quark matter in these objects. Based on the temperature estimate and cooling models we determine the critical temperature of triplet neutron superfluidity in the Vela core Tc=(7.5\pm 1.5)*10^9K which agrees well with recent data on behavior of nucleon interactions at high energies. Another finding is that in the middle aged neutron stars the vortex radiation, rather then thermal conductivity, is the main mechanism of heat transfer from the stellar core to the surface. Electron sound opens a perspective of direct spectroscopic study of superdense matter in the neutron star interiors.Comment: 43 pages, 7 figures, to appear in Astrophysical Journa

Evolved Gas Analysis of Mars Analog Samples from the Arctic Mars Analog Svalbard Expedition: Implications for Analyses by the Mars Science Laboratory

The 2011 Arctic Mars Analog Svalbard Expedition (AMASE) investigated several geologic settings on Svalbard, using methodologies and techniques being developed or considered for future Mars missions, such as the Mars Science Laboratory (MSL). The Sample Analysis at Mars (SAM) instrument suite on MSL consists of a quadrupole mass spectrometer (QMS), a gas chromatograph (GC), and a tunable laser spectrometer (TLS), which analyze gases created by pyrolysis of samples. During AMASE, a Hiden Evolved Gas Analysis-Mass Spectrometer (EGA-MS) system represented the EGA-QMS capability of SAM. Another MSL instrument, CheMin, will use x-ray diffraction (XRD) and x-ray fluorescence (XRF) to perform quantitative mineralogical characterization of samples. Field-portable versions of CheMin were used during AMASE. AMASE 2011 sites spanned a range of environments relevant to understanding martian surface materials, processes and habitability. They included the basaltic Sverrefjell volcano, which hosts carbonate globules, cements and coatings, carbonate and sulfate units at Colletth0gda, Devonian sandstone redbeds in Bockfjorden, altered basaltic lava delta deposits at Mt. Scott Keltie, and altered dolerites and volcanics at Botniahalvoya. Here we focus on SAM-like EGA-MS of a subset of the samples, with mineralogy comparisons to CheMin team results. The results allow insight into sample organic content as well as some constraints on sample mineralogy

Results from a set of three-dimensional numerical experiments of a hot Jupiter atmosphere.

ArticleThis is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this record.We present highlights from a large set of simulations of a hot Jupiter atmosphere, nominally based on HD 209458b, aimed at exploring both the evolution of the deep atmosphere, and the acceleration of the zonal flow or jet. We find the occurrence of a super-rotating equatorial jet is robust to changes in various parameters, and over long timescales, even in the absence of strong inner or bottom boundary drag. This jet is diminished in one simulation only, where we strongly force the deep atmosphere equator–to–pole temperature gradient over long timescales. Finally, although the eddy momentum fluxes in our atmosphere show similarities with the proposed mechanism for accelerating jets on tidally-locked planets, the picture appears more complex. We present tentative evidence for a jet driven by a combination of eddy momentum transport and mean flow

Heavy Quark Solitons

We investigate the heavy baryons which arise as solitonic excitations in a ``heavy meson" chiral Lagrangian which includes the light vector particles. It is found that the effect of the light vectors may be substantial. We also present a simple derivation which clearly shows the connection to the Callan-Klebanov approach.Comment: 13 pages; LaTex; SU-4240-532; UR 1306/ER-40685-755 (Minor typos corrected

Dirac Sea Effects on Superfluidity in Nuclear Matter

We study two kinds of Dirac sea effects on the $^1S_0$ pairing gap in nuclear matter based on the relativistic Hartree approximation to quantum hadrodynamics and the Gor'kov formalism. We show that the vacuum fluctuation effect on the nucleon effective mass is more important than the direct coupling between the Fermi sea and the Dirac sea due to the pairing interaction. The effects of the high-momentum cutoff are also discussed.Comment: 11 pages, 3 eps figures included, uses REVTeX (with \tightenlines

Heavy-Meson Observables at One-Loop in Partially Quenched Chiral Perturbation Theory

I present one-loop level calculations of the Isgur-Wise functions for B -> D^{(*)} + e + nu, of the matrix elements of isovector twist-2 operators in B and D mesons, and the matrix elements for the radiative decays D^* -> D + gamma in partially quenched heavy quark chiral perturbation theory. Such expressions are required in order to extrapolate from the light quark masses used in lattice simulations of the foreseeable future to those of nature.Comment: 13 pages, 3 fig