scholarly journals Revisited mass-radius relations for exoplanets below 120 M⊕

2020 ◽  
Vol 634 ◽  
pp. A43 ◽  
Author(s):  
J. F. Otegi ◽  
F. Bouchy ◽  
R. Helled
Keyword(s):  
Pure Water ◽  
Mass Range ◽  
Planetary Formation ◽  
Core Mass ◽  
Transiting Planets ◽  
Small Density ◽  
Different Populations ◽  
Formation And Evolution ◽  
The Masses ◽  
Two Populations

The masses and radii of exoplanets are fundamental quantities needed for their characterisation. Studying the different populations of exoplanets is important for understanding the demographics of the different planetary types, which can then be linked to planetary formation and evolution. We present an updated exoplanet catalogue based on reliable, robust, and, as much as possible accurate mass and radius measurements of transiting planets up to 120 M⊕. The resulting mass-radius (M-R) diagram shows two distinct populations, corresponding to rocky and volatile-rich exoplanets which overlap in both mass and radius. The rocky exoplanet population shows a relatively small density variability and ends at mass of ~25 M⊕, possibly indicating the maximum core mass that can be formed. We use the composition line of pure water to separate the two populations, and infer two new empirical M-R relations based on this data: M = (0.9 ± 0.06) R(3.45±0.12) for the rocky population, and M = (1.74 ± 0.38) R(1.58±0.10) for the volatile-rich population. While our results for the two regimes are in agreement with previous studies, the new M-R relations better match the population in the transition region from rocky to volatile-rich exoplanets, which correspond to a mass range of 5–25 M⊕, and a radius range of 2–3 R⊕.

scholarly journals Exoplanet characterisation in the longest known resonant chain: the K2-138 system seen by HARPS

2019 ◽  
Vol 631 ◽  
pp. A90 ◽  
Author(s):  
T. A. Lopez ◽  
S. C. C. Barros ◽  
A. Santerne ◽  
M. Deleuil ◽  
V. Adibekyan ◽  
...  
Keyword(s):  
Bayesian Analysis ◽  
Radial Velocity ◽  
Bright Star ◽  
Planetary Formation ◽  
Mass Measurements ◽  
Multiple Systems ◽  
Upper Limits ◽  
Low Mass ◽  
Formation And Evolution ◽  
The Masses

The detection of low-mass transiting exoplanets in multiple systems brings new constraints to planetary formation and evolution processes and challenges the current planet formation theories. Nevertheless, only a mere fraction of the small planets detected by Kepler and K2 have precise mass measurements, which are mandatory to constrain their composition. We aim to characterise the planets that orbit the relatively bright star K2-138. This system is dynamically particular as it presents the longest chain known to date of planets close to the 3:2 resonance. We obtained 215 HARPS spectra from which we derived the radial-velocity variations of K2-138. Via a joint Bayesian analysis of both the K2 photometry and HARPS radial-velocities (RVs), we constrained the parameters of the six planets in orbit. The masses of the four inner planets, from b to e, are 3.1, 6.3, 7.9, and 13.0 M⊕ with a precision of 34, 20, 18, and 15%, respectively. The bulk densities are 4.9, 2.8, 3.2, and 1.8 g cm−3, ranging from Earth to Neptune-like values. For planets f and g, we report upper limits. Finally, we predict transit timing variations of the order two to six minutes from the masses derived. Given its peculiar dynamics, K2-138 is an ideal target for transit timing variation (TTV) measurements from space with the upcoming CHaracterizing ExOPlanet Satellite (CHEOPS) to study this highly-packed system and compare TTV and RV masses.

scholarly journals Statistical Properties of Highly Luminous HII Regions in the Interacting Zone of the Antennae Galaxies, and Comparison with the Molecular Cloud Component

2012 ◽  
Vol 8 (S292) ◽  
pp. 156-156
Author(s):  
Joan Font ◽  
John E. Beckman ◽  
Javier Zaragoza ◽  
Santi Erroz-Ferrer ◽  
Begoña Garcia-Lorenzo
Keyword(s):  
Line Emission ◽  
Hii Regions ◽  
Molecular Data ◽  
Data Cube ◽  
Ionized Gas ◽  
La Palma ◽  
Fabry Perot ◽  
Different Populations ◽  
The Masses ◽  
Two Populations

AbstractWe have used the package CLOUDPROPS (Rosolowsky & Leroy 2008) in order to identify clouds, which are contained in data cubes of molecular/Hα line emission, and extract their properties. The molecular data cube is taken from the ALMA public archive and the ionized hydrogen data cube was obtained with the Fabry-Perot interferometer, GHαFaS, on the 4.2 m WHT in La Palma. In our study of the overlap region of the Antennae galaxies we have identified two populations of molecular clouds, above and below log M/M⊙ = 6.75 (in agreement with Wei et al. 2012 who find the break in mass at log M/M⊙ = 6.5) and two different populations of ionized gas clouds; the break in the luminosity occurs near log L = 37.6 (see Fig. 1). We have measured the masses, velocity dispersions and luminosities of the clouds, and derived relation between them for each population. Population II clouds (both molecular and ionized) tend to be located in the most luminous regions, while population I clouds can be found in the outskirts. This work will be published in Font et al. (2013).

scholarly journals HbA1c levels in individuals heterozygous for hemoglobin variants

2017 ◽  
Vol 63 (4) ◽  
pp. 341-346
Author(s):  
Ricardo Silva Tavares ◽  
Fábio Oliveira de Souza ◽  
Isabel Cristina Carvalho Medeiros Francescantonio ◽  
Weslley Carvalho Soares ◽  
Mauro Meira Mesquita
Keyword(s):  
Test Group ◽  
Exchange Chromatography ◽  
Group Method ◽  
Control Group ◽  
Significant Difference ◽  
Hemoglobin Variants ◽  
Different Populations ◽  
And Control ◽  
Two Populations ◽  
Hba1c Levels

Summary Objective: To evaluate the levels of glycated hemoglobin (HbA1c) in patients heterozygous for hemoglobin variants and compare the results of this test with those of a control group. Method: This was an experimental study based on the comparison of HbA1c tests in two different populations, with a test group represented by individuals heterozygous for hemoglobin variants (AS and AC) and a control group consisting of people with electrophoretic profile AA. The two populations were required to meet the following inclusion criteria: Normal levels of fasting glucose, hemoglobin, urea and triglycerides, bilirubin > 20 mg/dL and non-use of acetylsalicylic acid. 50 heterozygous subjects and 50 controls were evaluated between August 2013 and May 2014. The comparison of HbA1c levels between heterozygous individuals and control subjects was performed based on standard deviation, mean and G-Test. Results: The study assessed a test group and a control group, both with 39 adults and 11 children. The mean among heterozygous adults for HbA1c was 5.0%, while the control group showed a rate of 5.74%. Heterozygous children presented mean HbA1c at 5.11%, while the controls were at 5.78%. G-Test yielded p=0.93 for children and p=0.89 for adults. Conclusion: Our study evaluated HbA1c using ion exchange chromatography resins, and the patients heterozygous for hemoglobin variants showed no significant difference from the control group.

scholarly journals Genetic diversity in different populations of sloths assessed by DNA fingerprinting

2002 ◽  
Vol 62 (3) ◽  
pp. 503-508 ◽  
Author(s):  
N. MORAES ◽  
J. S. MORGANTE ◽  
C. Y. MIYAKI
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Dna Fingerprinting ◽  
Genetic Similarity ◽  
Similarity Indices ◽  
Different Populations ◽  
Related Individuals ◽  
Low Levels ◽  
Dna Profiles ◽  
Two Populations

In this study we analyzed a population of Bradypus torquatus with individuals originally distributed in different localities of Bahia, and two populations of B. variegatus with individuals from Bahia and São Paulo States. Using the DNA fingerprinting method, we assessed the genetic variability within and between populations. Analysis of the DNA profiles revealed genetic similarity indices ranging from 0.34 ± 0.07 to 0.87 ± 0.04. Similar low levels of genetic variability were found only in isolated mammalian populations or among related individuals. This study presents the first analyses of genetic diversity in sloth populations.

Arteriolar endothelial cell barrier separates two populations of muscarinic receptors

1992 ◽  
Vol 262 (4) ◽  
pp. H1311-H1315 ◽  
Author(s):  
R. J. Rivers ◽  
B. R. Duling
Keyword(s):  
Endothelial Cell ◽  
Muscarinic Receptors ◽  
Vessel Wall ◽  
Cheek Pouch ◽  
Different Populations ◽  
Differential Control ◽  
Two Sides ◽  
Two Populations

The endothelium of arterioles can function as a barrier to diffusion of hydrophilic molecules when studied in vitro. Thus a substance applied to one side of the arteriole is relatively ineffective in reaching receptors on the opposite side of the vessel wall unless it is lipid soluble. To study the receptor populations on the two sides of the arteriolar endothelium, we used micropipettes to apply methacholine (MCh; 1.0 microM), either luminally or adventitially, for 5 s to the arterioles of the cheek pouch of pentobarbital-anesthetized hamsters. MCh equally dilated the arterioles regardless of the side of application. That different populations of receptors are located on either side of the arteriole was shown by the fact that adventitially applied hydrophilic methscopolamine was ineffective in blocking the effects of the luminally applied MCh but completely blocked the effects of abluminally applied MCh. In contrast, the luminal population of receptors was easily blocked by adventially applied scopolamine, which is lipophilic. Separate and independent populations of receptors in the vessel wall suggests the potential for differential control between humoral and adventitial sources of vasoactive metabolites.

Population Symbiotic Evolution in a Model of Industrial Districts

2007 ◽  
pp. 301-316 ◽  
Author(s):  
U. Merlone
Keyword(s):  
Policy Making ◽  
Implementation Strategy ◽  
Parallel Implementation ◽  
Industrial Districts ◽  
Dynamic Complexity ◽  
Modeling Techniques ◽  
Different Populations ◽  
Two Populations ◽  
Simulation Environments

This chapter considers a model of industrial districts where different populations interact symbiotically. The approach consists of the parallel implementation of the model with jESOF and plain C++. We consider a district decomposition where two populations, workers and firms, cooperate while behaving independently. We can find interesting effects both in terms of worker localization consequences and of the dynamic complexity of the model, with policy resistance aspects.By using a multiple implementation strategy, we compare the advantages of the two modeling techniques and highlight the benefits arising when the same model is implemented on radically different simulation environments; furthermore we discuss and examine the results of our simulations in terms of policy-making effects.

scholarly journals Aggregate Evolution Mechanism during Ion-Adsorption Rare Earth Ore Leaching

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Kui Zhao ◽  
Yulong Zhuo ◽  
Xiaojun Wang ◽  
Wen Zhong
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Rare Earth ◽  
Ammonium Chloride ◽  
Particle Deposition ◽  
Pure Water ◽  
Particle Aggregation ◽  
Ion Adsorption ◽  
Aggregate Formation ◽  
Fine Soil ◽  
Formation And Evolution

The phenomenon of particle aggregation occurs when ammonium chloride is used as a leaching reagent to infiltrate rare earth samples. To reveal the formation and evolution mechanisms of aggregates, a self-developed column leaching experimental device was employed in conjunction with nuclear magnetic resonance technology. The relationships among the amount of rare earth leaching, the evolution of the microscopic pore structure, the porosity, and the leaching time were obtained. A comparative analysis of pure water and ammonium chloride test groups revealed that aggregates were present only in the latter. Consequently, the results of comprehensive analyses indicate that the formation of aggregates is a temporary particle deposition phenomenon caused by the settling of fine soil particles migrating from the top to the bottom of a sample. Furthermore, chemical exchanges constitute the main cause of aggregate formation.

scholarly journals Deep learning for intensity mapping observations: component extraction

2020 ◽  
Vol 496 (1) ◽  
pp. L54-L58 ◽  
Author(s):  
Kana Moriwaki ◽  
Nina Filippova ◽  
Masato Shirasaki ◽  
Naoki Yoshida
Keyword(s):  
Deep Learning ◽  
Galaxy Formation ◽  
Large Scale ◽  
Generative Adversarial Networks ◽  
Intensity Mapping ◽  
Adversarial Networks ◽  
Galaxy Formation And Evolution ◽  
Formation And Evolution ◽  
Emission Line Galaxies ◽  
Two Populations

ABSTRACT Line intensity mapping (LIM) is an emerging observational method to study the large-scale structure of the Universe and its evolution. LIM does not resolve individual sources but probes the fluctuations of integrated line emissions. A serious limitation with LIM is that contributions of different emission lines from sources at different redshifts are all confused at an observed wavelength. We propose a deep learning application to solve this problem. We use conditional generative adversarial networks to extract designated information from LIM. We consider a simple case with two populations of emission-line galaxies; H $\rm \alpha$ emitting galaxies at $z$ = 1.3 are confused with [O iii] emitters at $z$ = 2.0 in a single observed waveband at 1.5 $\mu{\textrm m}$. Our networks trained with 30 000 mock observation maps are able to extract the total intensity and the spatial distribution of H $\rm \alpha$ emitting galaxies at $z$ = 1.3. The intensity peaks are successfully located with 74 per cent precision. The precision increases to 91 per cent when we combine five networks. The mean intensity and the power spectrum are reconstructed with an accuracy of ∼10 per cent. The extracted galaxy distributions at a wider range of redshift can be used for studies on cosmology and on galaxy formation and evolution.

scholarly journals Distinction between distribution of masses of Wolf-Rayet stars and that of relativistic objects

2003 ◽  
Vol 212 ◽  
pp. 372-376
Author(s):  
Anatol M. Cherepashchuk
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Continuous Distribution ◽  
Core Mass ◽  
The Masses ◽  
Dependent Mass ◽  
Mass Dependent

The final masses MCO,f for the CO-cores of WR stars with known masses are calculated taking into account mass-dependent mass loss of WR stars and clumping structure of the WR wind which allows the mass loss rate to be decreased by a factor of 3. The masses of MCO,f lie in the range (1-2) - (20-44)M⊙ and have continuous distribution in contrast with distribution of masses Mx of relativistic objects. The distribution of Mx seems to be bimodal with a gap in the range Mx = 2-4 M⊙. A mean CO-core mass <MCO,f = 7.4-10.3 M⊙ is close to that of black holes: <MBH = 8-10 M⊙. Difference between distributions of MCO,f and Mx allows us to suggest that the nature of a formed relativistic object (neutron star, black hole) is determined not only by the mass of a progenitor but also by some other parameters: rotation, magnetic field, etc.

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