Exploration of the structure of giant planets with fast calculations and a bayesian approach

Abstract The Juno spacecraft is providing measurements of Jupiter's gravity field with an outstanding level of accuracy [3], leading to better constraints on the interior of Jupiter. Improving our knowledge of the internal structure of Jupiter is key, to understand the formation and the evolution of the planet [5,6] but also in the framework of exoplanets exploration. Hence, developing interiors models of Jupiter which are consistent with the observations is essential. Models of giant planets' internal structure are built with the code CEPAM [2] to compute the gravitational moments J2n [1] and compare them to the observational values. As the numerical calculation of the gravitational moments is crucial, we are here using a fast method based on a 4th order development of the Theory of Figures, coupled with the more precise CMS (Concentric MacLaurin Spheroid) method. This allows us to obtain reliable values of J2n in a reasonable amount of time. MCMC (Markov chain Monte Carlo) simulations are then run to study a wide range of interior models, using the above way to compute the gravitational moments. This bayesian approach leads to a broad investigation of the parameters range such as the chemical abundances, the 1 bar temperature or the transition pressure between the molecular hydrogen and metallic hydrogen layers. Important questions remain to be clarified like the distribution and amount of the heavy elements inside giant planets, following the hypothesis of a gradual distribution of the heavy elements up to a certain fraction of Jupiter's radius [7]. Throughout this talk, I will pay particular attention on the equations of state used in our models [4]. Indeed, giant planets' internal structure seems strongly linked to the physical properties of its components and it is critical to assess how sensitive to the equations of state our models are. References [1] Guillot, T., Miguel, Y. et al.: A suppression of differential rotation in Jupiter's deep interior, Nature, Vol 555, pp. 227-230, (2018). [2] Guillot, T. and Morel, P.: CEPAM: a code for modeling the interiors of giant planets, Astronomy and Astrophysics Supplement Series 109, 109-123 (1995) [3] Iess, L. et al.: Measurement of Jupiter's asymmetric gravity field, Nature, Vol 555, pp. 220-222, (2018). [4] Miguel, Y., Guillot, T. et al.: Jupiter internal structure: the effect of different equations of state. Astron. Astrophys. 596, A114 (2016) [5] Vazan, A., Helled, R. and Guillot, T.: Jupiter's evolution with primordial composition gradients. Astron. Astrophys. 610, L14 (2018). [6] Venturini, J., Helled, R.: Jupiter's heavy-element enrichment expected from formation models. Astron. Astrophys. 634, A31 (2020). [7] Wahl, S. M. et al.: Comparing Jupiter interior structure models to Juno gravity measurements and the role of a dilute core, Geophys. Res. Lett. Vol 44, pp. 4649-4659, (2017).

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Theory of low mass stars, brown dwarfs and extra-solar giant planets

Symposium - International Astronomical Union ◽

10.1017/s0074180900116857 ◽

1997 ◽

Vol 189 ◽

pp. 331-340 ◽

Cited By ~ 3

Author(s):

Gilles Chabrier ◽

Isabelle Baraffe

Keyword(s):

Equations Of State ◽

Galactic Disk ◽

Brown Dwarfs ◽

Reaction Rates ◽

Point Of View ◽

Giant Planets ◽

Substantial Contribution ◽

Mechanical And Thermal Properties ◽

Low Mass Stars ◽

Wide Range

Accurate modeling of the mechanical and thermal properties of very-lowmass stars (VLMS), Brown Dwarfs (BD) and Extra-solar Giant Planets (EGP) is of prior importance for a wide range of physical and astrophysical problems, from the fundamental physics point of view to the astrophysical and cosmological implications. They provide natural laboratories to test the different theories, equations of state, nuclear reaction rates, model atmospheres aimed at describing the physics of dense and cool objects. They represent the largest stellar population in the Galaxy, and thus provide a substantial contribution to the Galactic (disk) mass budget. Finally they represent one of the most intriguing questions in our understanding of the formation of star-like objects: are planet and star formation processes really different? Is there, and if so what is, a minimum mass for the formation of star-like objects? This field has blossomed recently with the discovery of several brown dwarfs (Nakajima et al, 1995; Rebolo et al., 1995) and numerous exoplanets since 51 Pegasi (Mayor and Queloz 1995; Mayor, this conference), which provide important information to challenge the theory.

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It is better an approximate answer to the right question than the exact answer to the wrong question : the case of the psychometric analysis of the ASQ:SE

10.31234/osf.io/a5tdf ◽

2020 ◽

Author(s):

Luis Anunciacao ◽

janet squires ◽

J. Landeira-Fernandez

Keyword(s):

Internal Structure ◽

Statistical Methods ◽

Principal Component ◽

Psychological Theory ◽

Published Data ◽

Multivariate Statistical ◽

Exact Answer ◽

Wide Range ◽

Ages And Stages Questionnaire ◽

The Right

One of the main activities in psychometrics is to analyze the internal structure of a test. Multivariate statistical methods, including Exploratory Factor analysis (EFA) and Principal Component Analysis (PCA) are frequently used to do this, but the growth of Network Analysis (NA) places this method as a promising candidate. The results obtained by these methods are of valuable interest, as they not only produce evidence to explore if the test is measuring its intended construct, but also to deal with the substantive theory that motivated the test development. However, these different statistical methods come up with different answers, providing the basis for different analytical and theoretical strategies when one needs to choose a solution. In this study, we took advantage of a large volume of published data (n = 22,331) obtained by the Ages and Stages Questionnaire Social-Emotional (ASQ:SE), and formed a subset of 500 children to present and discuss alternative psychometric solutions to its internal structure, and also to its subjacent theory. The analyses were based on a polychoric matrix, the number of factors to retain followed several well-known rules of thumb, and a wide range of exploratory methods was fitted to the data, including EFA, PCA, and NA. The statistical outcomes were divergent, varying from 1 to 6 domains, allowing a flexible interpretation of the results. We argue that the use of statistical methods in the absence of a well-grounded psychological theory has limited applications, despite its appeal. All data and codes are available at https://osf.io/z6gwv/.

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Wide-range equations of state for organic liquids

Proceedings of the Mavlyutov Institute of Mechanics ◽

10.21662/uim2007.1.011 ◽

2007 ◽

Vol 5 ◽

pp. 113-120 ◽

Cited By ~ 1

Author(s):

R.Kh. Bolotnova

Keyword(s):

High Pressures ◽

Equations Of State ◽

Organic Liquids ◽

Liquid Phases ◽

Wide Range ◽

High Pressures And Temperatures

The method of construction the wide-range equations of state for organic liquids, describing the gas and liquid phases including dissociation and ionization which occurs during an intense collapse of steam bubbles and accompanied by ultra-high pressures and temperatures, is proposed.

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Enzymes as a Reservoir of Host Defence Peptides

Current Topics in Medicinal Chemistry ◽

10.2174/1568026620666200327173815 ◽

2020 ◽

Vol 20 (14) ◽

pp. 1310-1323

Author(s):

Andrea Bosso ◽

Antimo Di Maro ◽

Valeria Cafaro ◽

Alberto Di Donato ◽

Eugenio Notomista ◽

...

Keyword(s):

Innate Immunity ◽

Biological Activity ◽

Internal Structure ◽

Catalytic Properties ◽

Cellular Responses ◽

Host Defence ◽

Present Review ◽

Active Peptides ◽

Wide Range

Host defence peptides (HDPs) are powerful modulators of cellular responses to various types of insults caused by pathogen agents. To date, a wide range of HDPs, from species of different kingdoms including bacteria, plant and animal with extreme diversity in structure and biological activity, have been described. Apart from a limited number of peptides ribosomally synthesized, a large number of promising and multifunctional HDPs have been identified within protein precursors, with properties not necessarily related to innate immunity, consolidating the fascinating hypothesis that proteins have a second or even multiple biological mission in the form of one or more bio-active peptides. Among these precursors, enzymes constitute certainly an interesting group, because most of them are mainly globular and characterized by a fine specific internal structure closely related to their catalytic properties and also because they are yet little considered as potential HDP releasing proteins. In this regard, the main aim of the present review is to describe a panel of HDPs, identified in all canonical classes of enzymes, and to provide a detailed description on hydrolases and their corresponding HDPs, as there seems to exist a striking link between these structurally sophisticated catalysts and their high content in cationic and amphipathic cryptic peptides.

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An information theoretic approach to link prediction in multiplex networks

Scientific Reports ◽

10.1038/s41598-021-92427-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Seyed Hossein Jafari ◽

Amir Mahdi Abdolhosseini-Qomi ◽

Masoud Asadpour ◽

Maseud Rahgozar ◽

Naser Yazdani

Keyword(s):

Real World ◽

Link Prediction ◽

Large Scale ◽

Similarity Measures ◽

Prediction Method ◽

General Purpose ◽

Fast Method ◽

Theoretic Approach ◽

Multiplex Networks ◽

Wide Range

AbstractThe entities of real-world networks are connected via different types of connections (i.e., layers). The task of link prediction in multiplex networks is about finding missing connections based on both intra-layer and inter-layer correlations. Our observations confirm that in a wide range of real-world multiplex networks, from social to biological and technological, a positive correlation exists between connection probability in one layer and similarity in other layers. Accordingly, a similarity-based automatic general-purpose multiplex link prediction method—SimBins—is devised that quantifies the amount of connection uncertainty based on observed inter-layer correlations in a multiplex network. Moreover, SimBins enhances the prediction quality in the target layer by incorporating the effect of link overlap across layers. Applying SimBins to various datasets from diverse domains, our findings indicate that SimBins outperforms the compared methods (both baseline and state-of-the-art methods) in most instances when predicting links. Furthermore, it is discussed that SimBins imposes minor computational overhead to the base similarity measures making it a potentially fast method, suitable for large-scale multiplex networks.

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The Structure of the Column in Stylidium

Australian Journal of Botany ◽

10.1071/bt9890081 ◽

1989 ◽

Vol 37 (1) ◽

pp. 81 ◽

Cited By ~ 4

Author(s):

N Findlay ◽

GP Findlay

Keyword(s):

Internal Structure ◽

Small Groups ◽

Central Layer ◽

Wide Range ◽

Single Column ◽

Cellulose Fibrils ◽

Shape And Size ◽

Fast Firing

In the genus Stylidium, the style and filaments of the flower are fused into a single column. In most species the column, when stimulated mechanically, undergoes a fast firing movement followed by a slow resetting movement. This movement is produced by changes in shape of a normally curved region of the column, the bend. In a wide range of species, the bend has a specialised anatomy and consists essentially of a longitudinal central layer of cells with two distinctive multi-celled layers of thick-walled cells on either side. The thick-walled cells are rich in cytoplasm with amyloplasts and vacuoles of varying sizes, and have non-lignified walls whose cellulose fibrils are arranged approximately transversely. Within the bend, the phloem occurs as discrete small groups of cells separated by some distance from the xylem. In species from the subgenus Centridium both the morphology and the internal structure of the bend differ somewhat from those in most species of Stylidium, and in two species of Stylidium with nonmoving columns, the characteristic cellular anatomy of the bend is entirely absent. The specialised anatomy of the cells and tissues in the bend are clearly associated with the movement of the column. Changes of shape and size of these cells are almost certainly responsible for the change in shape of the bend.

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Full exploration of the giant planet population around β Pictoris

Astronomy and Astrophysics ◽

10.1051/0004-6361/201730436 ◽

2018 ◽

Vol 612 ◽

pp. A108 ◽

Cited By ~ 11

Author(s):

A.-M. Lagrange ◽

M. Keppler ◽

N. Meunier ◽

J. Lannier ◽

H. Beust ◽

...

Keyword(s):

Extrasolar Planets ◽

Giant Planet ◽

Young Stars ◽

Giant Planets ◽

Close Orbit ◽

Wide Range ◽

Detection Probabilities ◽

Solar Type ◽

Formation And Evolution ◽

The One

Context. The search for extrasolar planets has been limited so far to close orbit (typ. ≤5 au) planets around mature solar-type stars on the one hand, and to planets on wide orbits (≥10 au) around young stars on the other hand. To get a better view of the full giant planet population, we have started a survey to search for giant planets around a sample of carefully selected young stars. Aims. This paper aims at exploring the giant planet population around one of our targets, β Pictoris, over a wide range of separations. With a disk and a planet already known, the β Pictoris system is indeed a very precious system for studies of planetary formation and evolution, as well as of planet–disk interactions. Methods. We analyse more than 2000 HARPS high-resolution spectra taken over 13 years as well as NaCo images recorded between 2003 and 2016. We combine these data to compute the detection probabilities of planets throughout the disk, from a fraction of au to a few dozen au. Results. We exclude the presence of planets more massive than 3 MJup closer than 1 au and further than 10 au, with a 90% probability. 15+ MJup companions are excluded throughout the disk except between 3 and 5 au with a 90% probability. In this region, we exclude companions with masses larger than 18 (resp. 30) MJup with probabilities of 60 (resp. 90) %.

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Jupiter internal structure: the effect of different equations of state

Astronomy and Astrophysics ◽

10.1051/0004-6361/201629732 ◽

2016 ◽

Vol 596 ◽

pp. A114 ◽

Cited By ~ 47

Author(s):

Y. Miguel ◽

T. Guillot ◽

L. Fayon

Keyword(s):

Internal Structure ◽

Equations Of State

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New insights on the dynamics of the Sumatra and Mariana complexes inferred from the comparative analysis of gravity data and model predictions

10.5194/egusphere-egu2020-7399 ◽

2020 ◽

Author(s):

Arcangela Bollino ◽

Anna Maria Marotta ◽

Federica Restelli ◽

Alessandro Regorda ◽

Roberto Sabadini

Keyword(s):

Comparative Analysis ◽

Gravity Field ◽

Wide Spectrum ◽

Gravity Data ◽

Gravity Anomalies ◽

Phase Changes ◽

Wide Range ◽

Model Predictions ◽

Dip Angle ◽

The Masses

Subduction is responsible for surface displacements and deep mass redistribution. This rearrangement generates density anomalies in a wide spectrum of wavelengths which, in turn, causes important anomalies in the Earth's gravity field that are visible as lineaments parallel to the arc-trench systems. In these areas, when the traditional analysis of the deformation and stress fields is combined with the analysis of the perturbation of the gravity field and its slow time variation, new information on the background environment controlling the tectonic loading phase can be disclosed.Here we present the results of a comparative analysis between the geodetically retrieved gravitational anomalies, based on the EIGEN-6C4 model, and those predicted by a 2D thermo-chemical mechanical modeling of the Sumatra and Mariana complexes.The 2D model accounts for a wide range of parameters, such as the convergence velocity, the shallow dip angle, the different degrees of coupling between the facing plates. The marker in cell technique is used to compositionally differentiate the system. Phase changes in the crust and in the mantle and mantle hydration are also allowed. To be compliant with the geodetic EIGEN-6C4 gravity data, we define a model normal Earth considering the vertical density distribution at the margins of the model domain, where the masses are not perturbed by the subduction process.Model predictions are in good agreement with data, both in terms of wavelengths and magnitude of the gravity anomalies measured in the surroundings of the Sumatra and Marina subductions. Furthermore, our modeling supports that the differences in the style of the gravity anomaly observed in the two areas are attributable to the different environments &#8211; ocean-ocean or ocean-continental subduction &#8211; that drives a significantly different dynamic in the wedge area.

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Tidal dissipation modelling in gaseous giant planets at the time of space missions

10.5194/epsc2021-762 ◽

2021 ◽

Author(s):

Hachem Dhouib ◽

Stéphane Mathis ◽

Florian Debras ◽

Aurélie Astoul ◽

Clément Baruteau

Keyword(s):

Internal Structure ◽

Differential Rotation ◽

Giant Planets ◽

Solid Core ◽

Large Radius ◽

Mixing Zone ◽

Convective Envelope ◽

Tidal Dissipation ◽

Hot Jupiters ◽

Tidal Waves

Gaseous giant planets (Jupiter and Saturn in our solar system and hot Jupiters around other stars) are turbulent rotating magnetic objects that have strong and complex interactions with their environment (their moons in the case of Jupiter and Saturn and their host stars in the case of hot Jupiters/Saturns). In such systems, the dissipation of tidal waves excited by tidal forces shape the orbital architecture and the rotational dynamics of the planets. During the last decade, a revolution has occurred for our understanding of tides in these systems. First, Lainey et al. (2009, 2012, 2017) have measured tidal dissipation stronger by one order of magnitude than expected in Jupiter and Saturn. Second, unexplained broad diversity of orbital architectures and large radius of some hot Jupiters are observed in exoplanetary systems. Finally, new constraints obtained thanks to Kepler/K2 and TESS indicate that tidal dissipation in gaseous giant exoplanets is weaker than in Jupiter and in Saturn (Ogilvie 2014, Van Eylen et al. 2018, Huber et al. 2019). Furthermore, the space mission JUNO and the grand finale of the CASSINI mission have revolutionized our knowledge of the interiors of giant planets. We now know, for example, that Jupiter is a very complex planet: it is a stratified planet with, from the surface to the core, a differentially rotating convective envelope, a first mixing zone (with stratified convection), a uniformly rotating magnetised convective zone, a second magnetized mixing zone (the diluted core, potentially in stratified convection) and a solid core (Debras & Chabrier 2019). So far, tides in these planets have been studied by assuming a simplified internal structure with a stable rocky and icy core (Remus et al. 2012, 2015) and a deep convective envelope surrounded by a thin stable atmosphere (Ogilvie & Lin 2004) where mixing processes, differential rotation and magnetic field were completely neglected. Our objective is thus to predict tidal dissipation using internal structure models, which agree with these last observational constrains. In this work, we build a new ab-initio model of tidal dissipation in giant planets that coherently takes into account the interactions of tidal waves with their complex stratification induced by the mixing of heavy elements, their zonal winds, and (dynamo) magnetic fields. This model is a semi-global model in the planetary equatorial plane. We study the linear excitation of tidal magneto-gravito-inertial progressive waves and standing modes. We take into account the buoyancy, the compressibility, the Coriolis acceleration (including differential rotation), and the Lorentz force. The tidal waves are submitted to the different potential dissipative processes: Ohmic, thermal, molecular diffusivities, and viscosity. We here present the general formalism and the potential regimes of parameters that should be explored. The quantities of interest such as tidal torque, dissipation, and heating are derived. This will pave the way for full 3D numerical simulations that will take into account complex internal structure and dynamics of gaseous giant (exo-)planets in spherical/spheroidal geometry. &#160;

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