scholarly journals Outgassing on stagnant-lid super-Earths

2018 ◽  
Vol 614 ◽  
pp. A18 ◽  
Author(s):  
C. Dorn ◽  
L. Noack ◽  
A. B. Rozel
Keyword(s):  
Scaling Laws ◽  
Thermal State ◽  
Mass Range ◽  
Refractory Element ◽  
Interior Structure ◽  
Mass Limit ◽  
Element Abundances ◽  
Astrophysical Data ◽  
Thermal States ◽  
Volcanic Outgassing

Aims. We explore volcanic CO2-outgassing on purely rocky, stagnant-lid exoplanets of different interior structures, compositions, thermal states, and age. We focus on planets in the mass range of 1–8 M⊕ (Earth masses). We derive scaling laws to quantify first- and second-order influences of these parameters on volcanic outgassing after 4.5 Gyr of evolution. Methods. Given commonly observed astrophysical data of super-Earths, we identify a range of possible interior structures and compositions by employing Bayesian inference modeling. The astrophysical data comprise mass, radius, and bulk compositional constraints; ratios of refractory element abundances are assumed to be similar to stellar ratios. The identified interiors are subsequently used as input for two-dimensional (2D) convection models to study partial melting, depletion, and outgassing rates of CO2. Results. In total, we model depletion and outgassing for an extensive set of more than 2300 different super-Earth cases. We find that there is a mass range for which outgassing is most efficient (~2–3 M⊕, depending on thermal state) and an upper mass where outgassing becomes very inefficient (~5–7 M⊕, depending on thermal state). At small masses (below 2–3 M⊕) outgassing positively correlates with planet mass, since it is controlled by mantle volume. At higher masses (above 2–3 M⊕), outgassing decreases with planet mass, which is due to the increasing pressure gradient that limits melting to shallower depths. In summary, depletion and outgassing are mainly influenced by planet mass and thermal state. Interior structure and composition only moderately affect outgassing rates. The majority of outgassing occurs before 4.5 Gyr, especially for planets below 3 M⊕. Conclusions. We conclude that for stagnant-lid planets, (1) compositional and structural properties have secondary influence on outgassing compared to planet mass and thermal state, and (2) confirm that there is a mass range for which outgassing is most efficient and an upper mass limit, above which no significant outgassing can occur. Our predicted trend of CO2-atmospheric masses can be observationally tested for exoplanets. These findings and our provided scaling laws are an important step in order to provide interpretative means for upcoming missions such as JWST and E-ELT, that aim at characterizing exoplanet atmospheres.

scholarly journals Parameterisations of interior properties of rocky planets

2020 ◽  
Vol 638 ◽  
pp. A129 ◽  
Author(s):  
Lena Noack ◽  
Marine Lasbleis
Keyword(s):  
Thermodynamic Properties ◽  
Scaling Laws ◽  
Thermal State ◽  
Thermal Evolution ◽  
Pure Water ◽  
Mass Composition ◽  
Temperature Profiles ◽  
Interior Structure ◽  
Water Ice ◽  
Simple Mass

Context. Observations of Earth-sized exoplanets are mostly limited to information on their masses and radii. Simple mass-radius relationships have been developed for scaled-up versions of Earth or other planetary bodies such as Mercury and Ganymede, as well as for one-material spheres made of pure water(-ice), silicates, or iron. However, they do not allow a thorough investigation of composition influences and thermal state on a planet’s interior structure and properties. Aims. In this work, we investigate the structure of a rocky planet shortly after formation and at later stages of thermal evolution assuming the planet is differentiated into a metal core and a rocky mantle (consisting of Earth-like minerals, but with a variable iron content). Methods. We derived possible initial temperature profiles after the accretion and magma ocean solidification. We then developed parameterisations for the thermodynamic properties inside the core depending on planet mass, composition, and thermal state. Results. We provide the community with robust scaling laws for the interior structure, temperature profiles, and core- and mantle-averaged thermodynamic properties for planets composed of Earth’s main minerals but with variable compositions of iron and silicates. Conclusions. The scaling laws make it possible to investigate variations in thermodynamic properties for different interior thermal states in a multitude of applications such as deriving mass-radius scaling laws or estimating magnetic field evolution and core crystallisation for rocky exoplanets.

scholarly journals SDSS-IV MaNGA: radial gradients in stellar population properties of early-type and late-type galaxies

2021 ◽  
Vol 502 (4) ◽  
pp. 5508-5527
Author(s):  
Taniya Parikh ◽  
Daniel Thomas ◽  
Claudia Maraston ◽  
Kyle B Westfall ◽  
Brett H Andrews ◽  
...  
Keyword(s):  
Stellar Population ◽  
Mass Range ◽  
Mass Relation ◽  
Individual Element ◽  
Late Type ◽  
Element Abundances ◽  
Entire Mass Range ◽  
Strong Gradient ◽  
Star Formation Histories ◽  
Absorption Features

ABSTRACT We derive ages, metallicities, and individual element abundances of early- and late-type galaxies (ETGs and LTGs) out to 1.5 Re. We study a large sample of 1900 galaxies spanning 8.6–11.3 log M/M⊙ in stellar mass, through key absorption features in stacked spectra from the SDSS-IV/MaNGA survey. We use mock galaxy spectra with extended star formation histories to validate our method for LTGs and use corrections to convert the derived ages into luminosity- and mass-weighted quantities. We find flat age and negative metallicity gradients for ETGs and negative age and negative metallicity gradients for LTGs. Age gradients in LTGs steepen with increasing galaxy mass, from −0.05 ± 0.11 log Gyr/Re for the lowest mass galaxies to −0.82 ± 0.08 log Gyr/Re for the highest mass ones. This strong gradient–mass relation has a slope of −0.70 ± 0.18. Comparing local age and metallicity gradients with the velocity dispersion σ within galaxies against the global relation with σ shows that internal processes regulate metallicity in ETGs but not age, and vice versa for LTGs. We further find that metallicity gradients with respect to local σ show a much stronger dependence on galaxy mass than radial metallicity gradients. Both galaxy types display flat [C/Fe] and [Mg/Fe], and negative [Na/Fe] gradients, whereas only LTGs display gradients in [Ca/Fe] and [Ti/Fe]. ETGs have increasingly steep [Na/Fe] gradients with local σ reaching 6.50 ± 0.78 dex/log km s−1 for the highest masses. [Na/Fe] ratios are correlated with metallicity for both galaxy types across the entire mass range in our sample, providing support for metallicity-dependent supernova yields.

scholarly journals Application of Causal Inference to the Analysis of Occupant Thermal State and Energy Behavioral Intentions in Immersive Virtual Environments

2021 ◽  
Vol 3 ◽  
Author(s):  
Girish Rentala ◽  
Yimin Zhu ◽  
Supratik Mukhopadhyay
Keyword(s):  
Causal Inference ◽  
Virtual Environments ◽  
Behavioral Intentions ◽  
Thermal State ◽  
Behavioral Factors ◽  
Immersive Virtual Environments ◽  
Virtual Experience ◽  
Energy Behavior ◽  
Thermal States

Identification and quantitative understanding of factors that influence occupant energy behavior and thermal state during the design phase are critical in supporting effective energy-efficient design. To achieve this, immersive virtual environments (IVEs) have recently shown potential as a tool to simulate occupant energy behaviors and collect context-dependent behavior data for buildings under design. On the other hand, prior models of occupant energy behaviors and thermal states used correlation-based approaches, which failed to capture the underlying causal interactions between the influencing factors and hence were unable to uncover the true causing factors. Therefore, in this study, the authors investigate the applicability of causal inference for identifying the causing factors of occupant/participant energy behavioral intentions and their thermal states in IVE condition and compare those results with the baseline in-situ condition. The energy behavioral intentions here are a proximal antecedent of actual energy behaviors. A set of experiments involving 72 human subjects were performed through the use of a head-mounted device (HMD) in a climate chamber. The subjects were exposed to three different step temperatures (cool, neutral, warm) under an IVE and a baseline in-situ condition. Participants' individual factors, behavioral factors, skin temperatures, virtual experience factors, thermal states (sensation, acceptability, comfort), and energy behavioral intentions were collected during the experiments. Structural causal models were learnt from data using the elicitation method in conjunction with the PC-Stable algorithm. The findings show that the causal inference framework is a potentially effective method for identifying causing factors of thermal states and energy behavioral intentions as well as quantifying their causal effects. In addition, the study shows that in IVE experiments, the participants' virtual experience factors such as their immersion, presence, and cybersickness were not the causing factors of thermal states and energy behavioral intentions. Furthermore, the study suggests that participants' behavioral factors such as their attitudes toward energy conservation and perceived behavioral control to conserve energy were the causing factors of their energy behavioral intentions. Also, the indoor temperature was a causing factor of general thermal sensation and overall skin temperature. The paper also discusses other findings, including discrepancies, limitations of the study, and recommendations for future studies.

scholarly journals The Thermal State and Interior Structure of Mars

2018 ◽  
Vol 45 (22) ◽  
pp. 12,198-12,209 ◽  
Author(s):  
A.‐C. Plesa ◽  
S. Padovan ◽  
N. Tosi ◽  
D. Breuer ◽  
M. Grott ◽  
...  
Keyword(s):  
Thermal State ◽  
Interior Structure

scholarly journals Background Radiation: Probes and Future Tests

1996 ◽  
Vol 168 ◽  
pp. 389-398
Author(s):  
Martin J. Rees
Keyword(s):  
Background Radiation ◽  
Light Element ◽  
Mass Range ◽  
Black Body ◽  
Big Bang ◽  
List Type ◽  
Microwave Background ◽  
Background Spectrum ◽  
Element Abundances ◽  
Microwave Background Radiation

The clearest evidence for the ‘hot big bang’ is of course the microwave background radiation. Its spectrum is now known, from the FIRAS experiment on COBE, to be a very precise black body – indeed, the deviations due to high-z activity, hot intergalactic gas, etc are smaller than many people might have expected. Also the light element abundances have remained concordant with the predictions of big bang nucleosynthesis, thereby giving us confidence in extrapolating back to when the universe was a few seconds old (see Copi, Schramm and Turner 1994 for a recent review). These developments give us grounds for greater confidence in this model than would have been warranted ten years ago. Several things could have happened which would have refuted the picture, but they haven't happened. For instance:(i)Objects could have been found where the helium abundance was far below 23 per cent.(ii)The background spectrum at millimetre wavelengths could have been weaker than a black body with temperature chosen to fit the Rayleigh-Jeans part of the spectrum.(iii)A stable neutrino might have been discovered in the mass range 100eV-1MeV.

scholarly journals A bestiary of black holes on the conifold with fluxes

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Alex Buchel
Keyword(s):  
Black Holes ◽  
Phase Transitions ◽  
Gauge Theory ◽  
Symmetry Breaking ◽  
Strong Coupling ◽  
Chiral Symmetry ◽  
Thermal State ◽  
Chiral Symmetry Breaking ◽  
Comprehensive Analysis ◽  
Thermal States

Abstract We present a comprehensive analysis of the black holes on warped deformed conifold with fluxes in Type IIB supergravity. These black holes realize the holographic dual to thermal states of the $$ \mathcal{N} $$ N = 1 supersymmetric SU(N) × SU(N + M) cascading gauge theory of Klebanov et al. [1, 2] on round S3. There are three distinct mass scales in the theory: the strong coupling scale Λ of the cascading gauge theory, the compactification scale μ = 1/L3 (related to the S3 radius L3) and the temperature T of a thermal state. Depending on Λ, μ and T, there is an intricate pattern of confinement/deconfinement (Hawking-Page) and the chiral symmetry breaking phase transitions. In the S3 → ℝ3 decompactification limit, i.e., μ → 0, we recover the Klebanov-Tseytlin [3] and the Klebanov-Strassler [4] black branes.

scholarly journals A comparison between higher-order nonclassicalities of SUP-engineered coherent and thermal states

2021 ◽  
Author(s):  
Deepak Deepak ◽  
Arpita Chatterjee
Keyword(s):  
Coherent State ◽  
Thermal State ◽  
Higher Order ◽  
Quantum States ◽  
Photon Statistics ◽  
Nonclassical Properties ◽  
Quantum Detector ◽  
Exact Calculations ◽  
First Time ◽  
Thermal States

We consider an experimentally obtainable SUP operator, defined by using a generalized superposition of products of field annihilation (a) and creation (a<sup>†</sup>) operators of the type, A = saa<sup>†</sup> + ta<sup>†</sup>a with s<sup>2</sup> + t<sup>2</sup>=1. We apply this SUP operator on coherent and thermal quantum states, the states thus produced are referred as SUP-operated coherent state (SOCS) and SUP-operated thermal state (SOTS), respectively. In the present work, we report a comparative study between the higher-order nonclassical properties of SOCS and SOTS. The comparison is performed by using a set of nonclassicality witnesses (e.g., higher-order antiubunching, higher-order sub-Poissonian photon statistics, higher-order squeezing, Agarwal-Tara parameter, Klyshko's condition). The existence of higher-order nonclassicalities in SOCS and SOTS have been investigated for the first time. In view of possible experimental verification of the proposed scheme, we present exact calculations to reveal the effect of non-unit quantum efficiency of quantum detector on higher-order nonclassicalities.

scholarly journals 9. Relationship between the Composition of Solid Solar-System Matter and Distance from the Sun

1977 ◽  
Vol 39 ◽  
pp. 551-559 ◽  
Author(s):  
J. T. Wasson
Keyword(s):  
Oort Cloud ◽  
Asteroid Belt ◽  
Refractory Element ◽  
The Sun ◽  
Ordinary Chondrites ◽  
Element Abundances ◽  
Fine Grained ◽  
The Earth ◽  
Degree Of Oxidation ◽  
Planetary Processes

The chondritic meteorites have “solar” compositions, indicating that they have avoided fractionation in planetary processes such as partial melting or fractional crystallization. Since chondrites contain solar proportions of volatiles having nebular condensation temperatures ≤500 K, it follows that agglomeration of grains and accretion to parent bodies occurred after the nebula had cooled to such low temperatures, and, that models calling for simultaneous condensation and accretion of high-temperature minerals such as Fe-Ni metal or ferromagnesian silicates are implausible.Two independent intergroup fractionations have been recognized in chondritic materials; refractory element abundances (e.g., the Ca/Si ratio) and degree of oxidation measured by the FeO/(FeO + MgO) ratio decrease through the chondrite sequence: carbonaceous-ordinary-IAB-E. Hiatus between groups result from incomplete sampling by the Earth of the original spectrum. A plausible speculation is that this sequence reflects formation at different nebular pressures and temperatures, the fine-grained, oxidized, volatile-rich carbonaceous chondrites forming at lower temperatures >5 AU from the Sun, and the reduced enstatite chrondrites forming at higher temperatures near the Sun. The high fall frequency of the three groups of ordinary chondrites suggests an origin in the asteroid belt. The degree of oxidation of the IAB chondrites appears to be slightly lower than that of the Earth, suggesting an origin near or slightly less than 1 AU from the Sun. The O-isotope compositions of chondrites are consistent with this picture.Asteroids tend to be light or dark, with a hiatus in properties between these two classes. This can be understood if the light materials are ordinary chondrites originally formed at 2.2-3.5 AU, whereas the dark materials originated at >5 AU, and were deposited in the asteroid belt during a later period as a result of a major increase in the influx of cometary materials through the inner sc1ar system associated with the generation of the Oort cloud of comets.

scholarly journals Quantum Criticality of Ground and Thermal States in XX Model

2009 ◽  
Vol 16 (02n03) ◽  
pp. 281-286 ◽  
Author(s):  
Wonmin Son ◽  
Vlatko Vedral
Keyword(s):  
Phase Transition ◽  
Ground State ◽  
Thermal Equilibrium ◽  
Thermal State ◽  
Quantum Criticality ◽  
Energy Spectra ◽  
Exact Form ◽  
Zero Temperature ◽  
Xx Model ◽  
Thermal States

Here, we compare the critical behaviour of the ground state and the thermal state of the XX model. We analyze full energy spectra and the exact form of eigenstates to reconstruct the ground state and the thermally excited state. With the solutions, we discuss the properties of quantum phase transition at zero temperature as well as the state in a thermal equilibrium.

NEW APPLICATION OF THERMO FIELD DYNAMICS IN SIMPLIFYING THE CALCULATION OF WIGNER FUNCTIONS

2003 ◽  
Vol 18 (11) ◽  
pp. 733-742 ◽  
Author(s):  
HONGYI FAN
Keyword(s):  
Matrix Element ◽  
Wigner Function ◽  
Thermal State ◽  
Ensemble Average ◽  
Wigner Functions ◽  
State Representation ◽  
Density Matrices ◽  
Wigner Operator ◽  
Thermo Field Dynamics ◽  
Thermal States

We find that the Thermo Field Dynamics, invented by Takahashi and Umezawa, can simplify calculations of Wigner functions for density matrices ρ. Using the coherent thermal state representation (Phys. Lett.A246, 242 (1998)), we show that the Wigner function W = Tr (Δρ) (an ensemble average of the Wigner operator Δ) can be expressed as a matrix element of ρ in the pure coherent thermal states. Wigner functions for some complicated density matrices are derived in this way.

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