scholarly journals Architecture of Planetary Systems Predicted from Protoplanetary Disks Observed with ALMA. I. Mass of the Possible Planets Embedded in the Dust Gap

2021 ◽  
Vol 923 (2) ◽  
pp. 165
Author(s):  
Shijie Wang ◽  
Kazuhiro D. Kanagawa ◽  
Yasushi Suto
Keyword(s):  
Planetary Systems ◽  
Protoplanetary Disks ◽  
Observation Data ◽  
Dust Disk ◽  
Consistent Manner ◽  
Dust Component ◽  
Gas Gap ◽  
Core Accretion ◽  
Gas Component

Abstract Recent ALMA observations have identified a variety of dust gaps in protoplanetary disks, which are commonly interpreted to be generated by unobserved planets. Predicting mass of such embedded planets is of fundamental importance in comparing those disk architectures with the observed diversity of exoplanets. The prediction, however, depends on the assumption that whether the same gap structure exists in the dust component alone or in the gas component as well. We assume a planet can only open a gap in the gas component when its mass exceeds the pebble isolation mass by considering the core-accretion scenario. We then propose two criteria to distinguish if a gap is opened in the dust disk alone or the gas gap as well when observation data on the gas profile is not available. We apply the criteria to 35 disk systems with a total of 55 gaps compiled from previous studies and classify each gap into four different groups. The classification of the observed gaps allows us to predict the mass of embedded planets in a consistent manner with the pebble isolation mass. We find that outer gaps are mostly dust alone, while inner gaps are more likely to be associated with a gas gap as well. The distribution of such embedded planets is very different from the architecture of the observed planetary systems, suggesting that significant inward migration is required in their evolution.

scholarly journals A Possible Role of Copernicus Sentinel-2 Data to Support Common Agricultural Policy Controls in Agriculture

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 110
Author(s):  
Filippo Sarvia ◽  
Elena Xausa ◽  
Samuele De Petris ◽  
Gianluca Cantamessa ◽  
Enrico Borgogno-Mondino
Keyword(s):  
Agricultural Policy ◽  
Common Agricultural Policy ◽  
Observation Data ◽  
Key Factor ◽  
Ndvi Time Series ◽  
Earth Observation Data ◽  
Four Levels ◽  
Nw Italy ◽  
Sentinel 2

Farmers that intend to access Common Agricultural Policy (CAP) contributions must submit an application to the territorially competent Paying Agencies (PA). Agencies are called to verify consistency of CAP contributions requirements through ground campaigns. Recently, EU regulation (N. 746/2018) proposed an alternative methodology to control CAP applications based on Earth Observation data. Accordingly, this work was aimed at designing and implementing a prototype of service based on Copernicus Sentinel-2 (S2) data for the classification of soybean, corn, wheat, rice, and meadow crops. The approach relies on the classification of S2 NDVI time-series (TS) by “user-friendly” supervised classification algorithms: Minimum Distance (MD) and Random Forest (RF). The study area was located in the Vercelli province (NW Italy), which represents a strategic agricultural area in the Piemonte region. Crop classes separability proved to be a key factor during the classification process. Confusion matrices were generated with respect to ground checks (GCs); they showed a high Overall Accuracy (>80%) for both MD and RF approaches. With respect to MD and RF, a new raster layer was generated (hereinafter called Controls Map layer), mapping four levels of classification occurrences, useful for administrative procedures required by PA. The Control Map layer highlighted that only the eight percent of CAP 2019 applications appeared to be critical in terms of consistency between farmers’ declarations and classification results. Only for these ones, a GC was warmly suggested, while the 12% must be desirable and the 80% was not required. This information alone suggested that the proposed methodology is able to optimize GCs, making possible to focus ground checks on a limited number of fields, thus determining an economic saving for PA and/or a more effective strategy of controls.

scholarly journals Observational constraints on dust disk sizes in tidally truncated protoplanetary disks in multiple systems in the Taurus region

2019 ◽  
Vol 628 ◽  
pp. A95 ◽  
Author(s):  
C. F. Manara ◽  
M. Tazzari ◽  
F. Long ◽  
G. J. Herczeg ◽  
G. Lodato ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Protoplanetary Disks ◽  
Mass Range ◽  
Outer Radius ◽  
Continuum Emission ◽  
Stellar Systems ◽  
Multiple Systems ◽  
Star Forming ◽  
Dust Disk ◽  
The Impact

The impact of stellar multiplicity on the evolution of planet-forming disks is still the subject of debate. Here we present and analyze disk structures around ten multiple stellar systems that were included in an unbiased, high spatial resolution survey performed with ALMA of 32 protoplanetary disks in the Taurus star-forming region. At the unprecedented spatial resolution of ~0.12′′ we detect and spatially resolve the disks around all primary stars, and those around eight secondary and one tertiary star. The dust radii of disks around multiple stellar systems are smaller than those around single stars in the same stellar mass range and in the same region. The disks in multiple stellar systems also show a steeper decay of the millimeter continuum emission at the outer radius than disks around single stars, suggestive of the impact of tidal truncation on the shape of the disks in multiple systems. However, the observed ratio between the dust disk radii and the observed separation of the stars in the multiple systems is consistent with analytic predictions of the effect of tidal truncation only if the eccentricities of the binaries are rather high (typically >0.5) or if the observed dust radii are a factor of two smaller than the gas radii, as is typical for isolated systems. Similar high-resolution studies targeting the gaseous emission from disks in multiple stellar systems are required to resolve this question.

Laminar Accretion in the Habitable Zone of Protoplanetary Disks

2012 ◽  
Vol 8 (S293) ◽  
pp. 250-255
Author(s):  
Xue-Ning Bai ◽  
James M. Stone
Keyword(s):  
Gas Flow ◽  
Protoplanetary Disks ◽  
Ambipolar Diffusion ◽  
Current Layer ◽  
Habitable Zone ◽  
Magnetorotational Instability ◽  
Strong Current ◽  
Consistent Manner ◽  
Inner Region ◽  
First Time

AbstractProtoplanetary disks (PPDs) are widely believed to be turbulent as a result of the magnetorotational instability (MRI). We perform magnetohydrodynamical simulations of PPDs that for the first time, take into account both Ohmic resistivity and ambipolar diffusion in a self-consistent manner. We show that in the inner region of PPDs that corresponds the habitable zone, the MRI is completely suppressed due to the interplay between magnetic field and ambipolar diffusion. The gas in this region is laminar throughout the entire vertical extent of the disk. Instead of MRI-driven accretion, a strong magnetocentrifugal wind is launched that efficiently carries away disk angular momentum. A physical wind geometry requires the presence of a strong current layer that is offset from the disk midplane where horizontal magnetic fields flip. We show that the entire accretion flow proceeds through this strong current layer. The non-turbulent nature of the gas flow strongly favors the habitable zone as the site for planetesimal formation, and has important implications for their subsequent growth into terrestrial planets.

scholarly journals Information-optimal Abstaining for Reliable Classification of Building Functions

2021 ◽  
Vol 2 ◽  
pp. 1-10
Author(s):  
Gabriel Dax ◽  
Martin Werner
Keyword(s):  
Regional Scale ◽  
Sensor Technology ◽  
Observation Data ◽  
Classification Schemes ◽  
The Past ◽  
Social Media Text ◽  
Novel Method ◽  
Earth Observation Data ◽  
Reliable Classification

Abstract. In the past decade, major breakthroughs in sensor technology and algorithms have enabled the functional analysis of urban regions based on Earth observation data. It has, for example, become possible to assign functions to areas in cities on a regional scale. With this paper, we develop a novel method for extracting building functions from social media text alone. Therefore, a technique of abstaining is applied in order to overcome the fact that most tweets will not contain information related to a building function albeit they have been sent from a specific building as well as the problem that classification schemes for building functions are overlapping.

scholarly journals Dynamic processes in the phonetic system of present-day dialects of Udmurt (on the material of central dialects)

2020 ◽  
Vol 11 (4) ◽  
pp. 391-402
Author(s):  
Natalia V. Kondratieva ◽  
Olga L. Sokolova
Keyword(s):  
Present State ◽  
Target Selection ◽  
Age Groups ◽  
Field Work ◽  
Research Data ◽  
Dynamic Processes ◽  
Observation Data ◽  
Udmurt Republic ◽  
Descriptive Method

Introduction. The article deals with the dynamic processes in the phonetic system of Bol’shoi Zhuzhges dialect of Udmurt in its present state. Materials and methods. The main source of the research is the audio materials recorded by the authors of the paper in the villages Bol’shoi Zhuzhges, Malyi Zhuzhges and Kosoevo of Uva district of the Udmurt Republic from 52 informants in five age groups: 10–18 , 18–30, 30–50, 50–70 and over 70 year old. The article employs a complex of methods is used to conduct the research: data collecting “field work” (conversation, direct questions, questionnaires, interviews, observation of speech activities, target selection); the descriptive method (observation, data comparing, generalization as well as interpretation and classification of the materials); с) comparative-historical and qualitative-statistic. Research and Discussion. The analysis of the field materials reveals that the shift in the use of dialects in the speech of people of different age groups primarily includes the following linguistic phenomena: the use of affricates, adding non-etymological sounds in the end of words, vowel correspondence, assimilation of sounds in word stems and affixes. Conclusion. The linguistic processes occurring in the Bol’shoi Zhuzhges develop slowly, which creates a situation when different language variants are revealed in the speech of different age groups within the same dialect. Dynamic processes in the phonetic system of the dialect are determined by intra- and extralinguistic factors.

scholarly journals SMA and ALMA studies of protoplanetary disk formation around low-mass protostars

2015 ◽  
Vol 11 (S315) ◽  
pp. 126-129
Author(s):  
Shigehisa Takakuwa ◽  
Nagayoshi Ohashi ◽  
Hsi-Wei Yen ◽  
Ti-Lin Chou ◽  
Kazuya Saigo ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Large Scale ◽  
Planetary Systems ◽  
Protoplanetary Disks ◽  
Protoplanetary Disk ◽  
Evolutionary Trend ◽  
Disk Formation ◽  
Systematic Survey ◽  
Angular Momenta ◽  
Low Mass

AbstractWe report our systematic survey observations of protostellar sources with the SubMillimeter Array (SMA) and Atacama Large Millimeter/submillimeter Array (ALMA). The purpose of our survey is to investigate formation mechanism of protoplanetary disks, precursors of planetary systems, out of ~1000 AU-scale protostellar envelopes surrounding the protostars. We found that in the early protostars (B335, NGC1333 IRAS 4B), the envelopes do not show significant rotating motions but infalling motions toward the central protostars. In more evolved protostars (L1527 IRS, L1448-mm, L1551 IRS 5), the envelopes are infalling and rotating with the conserved specific angular momenta (that is, vrot ∝ r−1). In most evolved sources (L1551 NE, TMC-1A, L1489 IRS) large-scale (≳100 AU) disks in Keplerian rotation or protoplanetary disks are evident. These results demonstrate a systematic evolutionary trend of envelope gas motions toward the disk formation.

Nursery for Planets

2017 ◽  
Author(s):  
John Chambers ◽  
Jacqueline Mitton
Keyword(s):  
Solar System ◽  
Immanuel Kant ◽  
Kuiper Belt ◽  
Planetary Systems ◽  
Protoplanetary Disks ◽  
Young Stars ◽  
Asteroid Belt ◽  
Two Dimensional

This chapter illustrates how the solar system has a decidedly two-dimensional aspect to it. The orbits of the eight major planets all lie in almost the same plane, deviating by no more than seven degrees. Bodies in the asteroid belt and the Kuiper belt stray a little further afield, but these belts are arranged like flattened donuts, aligned with the same plane as the planets. Immanuel Kant and Pierre-Simon de Laplace noted the planar nature of the solar system and used this as the basis for their nebular theories in which the solar system grew out of a flattened disk of matter. Young stars like those in the constellation Orion are often surrounded by disk-shaped clouds of gas and dust. Astronomers quickly dubbed these “protoplanetary” disks, assuming that they will someday form planetary systems.

Zooming in on the Chemistry of Protoplanetary Disks with ALMA

2017 ◽  
Vol 13 (S332) ◽  
pp. 57-68
Author(s):  
L. Ilsedore Cleeves
Keyword(s):  
Chemical Composition ◽  
Physical Properties ◽  
Spatial Resolution ◽  
Planetary Systems ◽  
Protoplanetary Disks ◽  
Building Blocks ◽  
Young Stars ◽  
Molecular Gas

AbstractDuring the first few ~Myr of a young stars life, it is encircled by a disk made up of molecular gas, dust, and ice – the building blocks for future planetary systems. How/when these disks form planets and what sets the planets initial compositions remain key outstanding questions in disk science. In recent years, major leaps in sensitivity and spatial resolution afforded by the Atacama Large Millimeter/Submillimeter Array (ALMA) have revolutionized our understanding of protoplanetary disks chemical composition and physical properties, revealing in some cases complex radial, vertical, and azimuthal structure in the dust and gas. In this contribution, I review recent observational results and new theoretical puzzles, and how these fit into a newly emerging picture of the disk environment.

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