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1. Developing Decision Aids to Enable Human Spaceflight Autonomy

Author

Frank, Jeremy D., NASA Ames Research Center, McGuire, Kerry, NASA Johnson Space Center, Moses, Haifa R., and Stephenson, Jerri

Abstract

As NASA explores destinations beyond the Moon, the distance between Earth and spacecraft will increase communication delays between astronauts and Mission Control. Today, astronauts coordinate with Mission Control to request assistance and await approval to perform tasks. Many of these coordination tasks require multiple exchanges of information, (for example, taking turns). In the presence of long communication delays, the length of time between turns may lead to inefficiency, or increased mission risk. Future astronauts will need software-based decision aids to enable them to work autonomously from Mission Control. These tools require the right combination of mission operations functions, for example, automated planning and fault management, troubleshooting recommendations, easy to access information, and just-in-time training. Ensuring these elements are properly designed and integrated requires an integrated human factors approach. This article describes a recent demonstration of autonomous mission operations using a novel software-based decision aid onboard the International Space Station. We describe how this new technology changes the way astronauts coordinate with mission control, and how the lessons learned from these early demonstrations will enable the operational autonomy needed to ensure astronauts can safely journey to Mars, and beyond.

Published
2017

2. A JavaPathfinder Extension to Analyse Human-Machine Interactions

Author

UCL - SST/ICTM/INGI - Pôle en ingénierie informatique, NASA Ames Research Center Moffett Field, USA, Combéfis, Sébastien, Giannakopoulou, Dimitra, Pecheur, Charles, Mehlitz, Peter, The Java Pathfinder Workshop 2011, UCL - SST/ICTM/INGI - Pôle en ingénierie informatique, NASA Ames Research Center Moffett Field, USA, Combéfis, Sébastien, Giannakopoulou, Dimitra, Pecheur, Charles, Mehlitz, Peter, and The Java Pathfinder Workshop 2011

Abstract

We present jpf-hmi, a Java Pathfinder (JPF) extension that supports the description and analysis of human machine interaction (HMI) systems. The extension is built on top of jpf-statechart, but differentiates between events in terms of commands, observations and internal actions, as it is typical in the HMI domain. jpf-hmi implements two algorithms for generating concise system models for human operators. It also supports the detection of several types of HMI-specific anomalies known as “automation surprises”, such as non full-control determinism and mode confusion. These capabilities are provided in addition to the existing more generic property verification that is supported by JPF, and which can also be applied to HMI systems.

Published
2011

3. Learning system abstractions for human operators

Author

UCL - SST/ICTM/INGI - Pôle en ingénierie informatique, NASA Ames Research Center Moffett Field, USA, Combéfis, Sébastien, Giannakopoulou, Dimitra, Pecheur, Charles, Feary, Michael, International Workshop on Machine Learning Technologies in Software Engineering, UCL - SST/ICTM/INGI - Pôle en ingénierie informatique, NASA Ames Research Center Moffett Field, USA, Combéfis, Sébastien, Giannakopoulou, Dimitra, Pecheur, Charles, Feary, Michael, and International Workshop on Machine Learning Technologies in Software Engineering

Abstract

This paper is concerned with the use of formal techniques for the analysis of human-machine interactions (HMI). The focus is on generating system abstractions for human operators. Such abstractions, once expressed in rigorous, formal notations, can be used for analysis or for user training. They should ideally be minimal in order to concisely capture the system behaviour. They should also contain enough infor- mation to allow full-control of the system. This work addresses the problem of automatically generating abstractions, based on formal descriptions of system behaviour. Previous work presented a bisimulation-based technique for constructing minimal full-control abstractions. This paper proposes an alternative approach based on the use of the L learning algorithm. In particular, minimal abstractions are generated from learned three-valued deterministic nite-state automata. The learning-based approach is applied on a number of examples and compared to the bisimulation-based approach. The result of these comparisons is that there is no clear winner. However, the proposed approach has wider applicability since it can handle more types of systems than the bisimulation-based technique. Moreover, if no full-control abstraction can be generated due to a form of non-determinism in the system, the learning-based approach provides counterexamples that allow to detect and analyze that non-determinism. We also discuss how the well-known HMI issue of mode confusion can be analyzed through this approach.

Published
2011

4. A formal framework for design and analysis of Human-Machine interaction

Author

UCL - SST/ICTM/INGI - Pôle en ingénierie informatique, NASA Ames Research Center Moffett Field, USA, Combéfis, Sébastien, Giannakopoulou, Dimitra, Pecheur, Charles, Feary, Michael, International Conference on Systems, Man, and Cybernetics, UCL - SST/ICTM/INGI - Pôle en ingénierie informatique, NASA Ames Research Center Moffett Field, USA, Combéfis, Sébastien, Giannakopoulou, Dimitra, Pecheur, Charles, Feary, Michael, and International Conference on Systems, Man, and Cybernetics

Abstract

Automated systems are increasingly complex, making it hard to design interfaces for human operators. Humanmachine interaction (HMI) errors like automation surprises are more likely to appear and lead to system failures or accidents. In previous work, we studied the problem of generating system abstractions, called mental models, that facilitate system understanding while allowing proper control of the system by operators as defined by the full-control property. Both the domain and its mental model have Labelled Transition Systems (LTS) semantics, and we proposed algorithms for automatically generating minimal mental models as well as checking full-control. This paper presents a methodology and an associated framework for using the above and other formal method based algorithms to support the design of HMI systems. The framework can be used for modelling HMI systems and analysing models against HMI vulnerabilities. The analysis can be used for validation purposes or for generating artifacts such as mental models, manuals and recovery procedures. The framework is implemented in the JavaPathfinder model checker. Our methodology is demonstrated on two examples, an existing benchmark of a medical device, and a model generated from the ADEPT toolset developed at NASA Ames. Guidelines about how ADEPT models can be translated automatically into JavaPathfinder models are also discussed.

Published
2011

5. Chemistry Model for Ablating Carbon-Phenolic Material During Atmospheric Re-Entry

Author

University of Michigan, Ann Arbor, MI, NASA Ames Research Center, Moffet Field, CA, Martin, Alexandre, Boyd, Iain, Cozmuta, Ioana, Wright, Michael, University of Michigan, Ann Arbor, MI, NASA Ames Research Center, Moffet Field, CA, Martin, Alexandre, Boyd, Iain, Cozmuta, Ioana, and Wright, Michael

Published
2011

6. Low-Speed and High-Speed Correlation of Smart Active Flap Rotor Loads

Author

ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Kottapalli, Sesi, ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, and Kottapalli, Sesi

Abstract

Measured, open loop and closed loop data from the SMART rotor test in the NASA Ames 40- by 80- Foot Wind Tunnel are compared with CAMRAD II calculations. One open loop high-speed case and four closed loop cases are considered. The closed loop cases include three high-speed cases and one low-speed case. Two of these high-speed cases include a 2 deg flap deflection at 5P case and a test maximum-airspeed case. This study follows a recent, open loop correlation effort that used a simple correction factor for the airfoil pitching moment Mach number. Compared to the earlier effort, the current open loop study considers more fundamental corrections based on advancing blade aerodynamic conditions. The airfoil tables themselves have been studied. Selected modifications to the HH-06 section flap airfoil pitching moment table are implemented. For the closed loop condition, the effect of the flap actuator is modeled by increased flap hinge stiffness. Overall, the open loop correlation is reasonable, thus confirming the basic correctness of the current semi-empirical modifications; the closed loop correlation is also reasonable considering that the current flap model is a first generation model. Detailed correlation results are given in the paper., Presented at the American Helicopter Society Aeromechanics Specialists Conference, held in San Francisco, CA, on 20-22 Jan 2010.

Published
2010

7. Large-Scale Domain Decomposition for a Scalable, Three-dimensional Brick Finite Element Based Rotor Dynamic Analysis

Author

ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Datta, Anubhav, Johnson, Wayne, ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Datta, Anubhav, and Johnson, Wayne

Abstract

This paper implements and analyzes a dual-primal iterative substructuring method for the parallel and scalable solution of a three-dimensional finite element based dynamic analysis of helicopter rotor blades. Scalability and solution times are studied using two prototype problems -- one for steady hover (symmetric) and one for transient forward flight (non-symmetric) -- carried out on up to 128 processors. Several problem sizes of up to 0.48 million degrees of freedom are considered. A linear speed-up is observed with number of processors up to the point of substructure optimality. Substructure optimality and hence linear speed-up are shown to depend dramatically on the corner based global coarse problem selection. A minimal selection is implemented in this paper consisting only of corner nodes that lie on substructure vertices while the remaining corner nodes on substructure edges are treated as interface nodes with multiple dual variables. The key conclusion is that this minimal selection is key to extending linear speed-up to as high a processor number as possible, and minimizing the solution time for a fixed problem size. It is therefore an essential requirement for the efficient solution of a large-scale 3-D FEM problem., Presented at the American Helicopter Society Specialists' Conference on Aeromechanics, held in San Francisco, CA, on 20-22 Jan 2010.

Published
2010

8. A Multibody Formulation for Three Dimensional Brick Finite Element Based Parallel and Scalable Rotor Dynamic Analysis

Author

ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Datta, Anubhav, Johnson, Wayne, ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Datta, Anubhav, and Johnson, Wayne

Abstract

This paper presents a unified formulation for a 3-dimensional finite element based non-linear multibody analysis for helicopter rotors. Special multibody brick elements are developed which can be used to embed arbitrary joint rotations within a 3-dimensional structure. A multi-level iterative substructuring algorithm, that is parallel and scalable, is redesigned to accommodate multibody components in a manner that maintains its underlying numerical scalability. The brick multibody formulation is then used to study the impact of non-linear 3-dimensional hub end effects in rotors that are not modeled by current generation beam based models. The constraints that arise from a physical 3-D connection of a rotor blade to a joint are shown to alter the internal stresses at its hub end and impact torsion dynamics significantly - a physics that is uniquely rotary wing in nature. Large scale structural models are then constructed for a hingeless, an articulated, and a bearingless rotor, consisting of multiple flexible components and multibody connections near the hub end, and containing up to 0.48 million degrees of freedom. The models are analyzed for scalability and timing for hover and forward flight solutions on up to 128 processors. The key conclusion is that multibody components can indeed be incorporated within a fully parallel multi-level iterative substructuring algorithm without impacting its numerical scalability. And, integrated carefully within 3-dimensional brick elements, they open new opportunities for capturing fundamental physics of 3-dimensional stress fields on rotary wing structures., Presented at the American Helicopter Society 66th Annual Forum, Phoenix, AZ, May 11-13, 2010.

Published
2010

9. Canaleparolina darwiniensis, gen. nov., sp. nov., and other pillotinaceae spirochetes from insects

Author

Andrew Wier; Department of Geosciences, University of Massachusetts, Amherst, Massachusetts, USA, Jon Ashen; NASA Ames Research Center, Moffett Field, California, USA, Lynn Margulis; Department of Geosciences, University of Massachusetts, Amherst, Massachusetts, USA, Andrew Wier; Department of Geosciences, University of Massachusetts, Amherst, Massachusetts, USA, Jon Ashen; NASA Ames Research Center, Moffett Field, California, USA, and Lynn Margulis; Department of Geosciences, University of Massachusetts, Amherst, Massachusetts, USA

Abstract

We describe two new pillotinaceous spirochetes (Canaleparolina darwiniensis, Diplocalyx cryptotermitidis) and identify for the first time Hollandina pterotermitidisfrom both the subterranean termite Cryptotermes cavifrons and the wood-eating cockroach Cryptocercus punctulatus based on morphometric analysis of transmission electron micrographic thin sections. C. darwiniensis, gen. nov., sp. nov., limited to near Darwin, Australia, invariably is present on the surface of the treponeme-studded trichomonad Mixotricha paradoxa, a consistent inhabitant of the hindgut of healthy termite Mastotermes darwiniensis. The spirochete both attached to the surface of protists and free-swimming in the paunch (hindgut) lumen of the insect has 16 periplasmic flagella (16:32:16) and imbricated wall structures that resemble flattened crenulations of Pillotina. The flagella surround half the protoplasmic cylinder. C. darwiniensis is the largest (0.5 μm diameter × 25 μm length) of the three epibiotic bacteria (two spirochetes, one rod) that comprise the complex cortex of its host Mixotricha paradoxa. Several criteria distinguish Diplocalyx cryptotermitidis sp. nov. isolated from Cryptotermes cavifrons intestine: smaller diameter, fewer flagella, absence of inner and outer coats of the outer membrane, wider angle subtended by its flagella and, most notably, cytoplasmic tubuleassociated centers, which are periodic electron dense spheres within the protoplasmic cylinder from which emanate cytoplasmic tubules up to 24 nm in diameter. This is also the first report of abundant populations of Hollandina in Cryptotermes cavifrons (those populations belong to the species H. pterotermitidis). Morphometric analysis of the first thin sections of any spirochetes (published nearly 40 years ago by A.V. Grimstone) permits us to identify the large (0.9 μm diameter) free-swimming intestinal symbiont of Cryptocercus punctulatus also as Hollandina pterotermitidis.

Published
2010

11. Full-scale wind tunnel study of nacelle shape on cooling drag

Author

Michigan, University, Ann Arbor, Mich., NASA, Ames Research Center, Moffett Field, Calif., Corsiglia, V. R., Katz, J., Kroeger, R. A., Michigan, University, Ann Arbor, Mich., NASA, Ames Research Center, Moffett Field, Calif., Corsiglia, V. R., Katz, J., and Kroeger, R. A.

Published
2010

12. Three-Dimensional Finite Element Formulation and Scalabel Domain Decomposition for High Fidelity Rotor Dynamic Analysis

Author

ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Datta, Anubhav, Johnson, Wayne, ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Datta, Anubhav, and Johnson, Wayne

Abstract

This paper implements and analyzes a dual-primal iterative substructuring method, that is parallel and scalable, for the solution of a three-dimensional finite element dynamic analysis of helicopter rotor blades. The finite element analysis is developed using isoparametric hexahedral brick elements. Particular emphasis is placed on the formulation of the inertial terms that are unique to rotary wing structures. The scalability of the solution procedure is studied using two prototype problems { one for steady hover (symmetric) and one for transient forward flight (non-symmetric) - both carried out on up to 48 processors. In both hover and forward flight, a linear speed-up is observed with number of processors, up to the point of substructure optimality. Substructure optimality and the range of linear speed-up are shown to depend both on the problem size as well as a corner based global coarse problem selection. An increase in problem size extends the linear speed-up range up to the new substructure optimality. A superior coarse problem selection extends the optimality to a higher number of processors. The method also scales with respect to problem size. The key conclusion is that a three-dimensional finite element analysis of a rotor can be carried out in a fully parallel and scalable manner. The careful selection of substructure corner nodes, that are used to construct the global coarse problem, is the key to extending linear speed-up to as high a processor number as possible, thus minimizing the solution time for a given problem size., Presented at the American Helicopter Society Annual Forum (65th), Grapevine, TX on 27-29 May 2009. Prepared in collaboration with the Aeromechanics Branch, NASA Ames Research Centers, Moffett Field, CA

Published
2009

13. An Assessment of the State-of-the-Art in Multidisciplinary Aeromechanical Analyses

Author

ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Datta, Anubhav, Johnson, Wayne, ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Datta, Anubhav, and Johnson, Wayne

Abstract

This paper presents a survey of the current state-of-the-art in multidisciplinary aeromechanical analyses which integrate advanced Computational Structural Dynamics (CSD) and Computational Fluid Dynamics (CFD) methods. The application areas to be surveyed include fixed wing aircraft, turbomachinery, and rotary wing aircraft. The objective of the authors in the present paper -- together with a companion paper on requirements -- is to lay out a path for a High Performance Computing (HPC) based next generation comprehensive rotorcraft analysis. From this survey of the key technologies in other application areas it is possible to identify the critical technology gaps that stem from unique rotorcraft requirements., Presented at the AHS Specialist's Conference on Aeromechanics, San Francisco, CA, January 23-25, 2008.

Published
2008

14. Enhanced Field Emission Properties from Carbon Nanotube Emitters Grown on NiCr Alloy Surfaces with Grain Boundary Effect

Author

ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Yim, Setha, Ohta, Richiro, Killian, Jessie L., Zuckerman, Nathaniel B., Allen, Emily, Nguyen, Cattien V., ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Yim, Setha, Ohta, Richiro, Killian, Jessie L., Zuckerman, Nathaniel B., Allen, Emily, and Nguyen, Cattien V.

Abstract

Carbon nanotubes (CNTs) are known to have exceptional field emission properties such as low turn-on voltage and high current density. Nilsson et al. reported that field emission properties depend highly on the density of the CNT films. The CNTs must have low density in order to minimize electrostatic field screening from neighboring nanotubes. At the same time, the CNT films must have a high number of emitting sites to achieve a desirable current density. Recently, the direct growth of CNTs on metal alloys containing Ni, Cr, and Fe has been shown to be an attractive alternative for fabrication of CNT emitters without requiring a metal catalyst deposition step. Herein, we report the field emission properties of multi-walled carbon nanotube (MWNT) films grown on polished smooth 80/20 and 70/30 NiCr surfaces by thermal chemical vapor deposition. We show that 80/20 NiCr surfaces prohibit growth of MWNTs at the grain boundaries resulting in a lower turn-on field in comparison to a continuous MWNT film obtained with 70/30 NiCr substrates., See also ADM002087. Presented at the 2008 IEEE International Vacuum Electronic Conference (IVEC 2008) (9th) Held in Monterey, CA on April 22-24, 2008. Published in the Proceedings of the 2008 IEEE International Vacuum Electronic Conference (IVEC 2008) (9th) p433-434, 2008. The original document contains color images.

Published
2008

15. Field Emission Properties of Carbon Nanotube Pillar Arrays Patterned Directly on Metal Alloy Surfaces

Author

ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Killian, Jessica L., Niemann, Darrell L., Silan, Nathaniel Zuckerman ;Jeremy, Ribaya, Bryan P., Rahman, Mahmud, Meyyappan, M., Nguyen, Cattien V., ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Killian, Jessica L., Niemann, Darrell L., Silan, Nathaniel Zuckerman ;Jeremy, Ribaya, Bryan P., Rahman, Mahmud, Meyyappan, M., and Nguyen, Cattien V.

Abstract

Carbon nanotube pillar arrays (CPAs) for cold field emission were fabricated using a conventional photolithography process, and the geometry of these arrays was studied and the effect of pillar height on field emission was quantified. Our CPA samples achieved turn-on fields as low as 0.9 V/micrometer and stable current densities of 10 mA/cm(2) at applied field lower than 6V/micrometer., See also ADM002087. Presented at the 2008 IEEE International Vacuum Electronic Conference (IVEC 2008) (9th) Held in Monterey, CA on April 22-24, 2008. Published in the Proceedings of the 2008 IEEE International Vacuum Electronic Conference (IVEC 2008) (9th) p435-436, 2008. The original document contains color images.

Published
2008

16. Testing Planning Domains (without Model Checkers)

Author

University College London - Department of Computer Science, UCL - FSA/INGI - Département d'ingénierie informatique, RIACS - NASA Ames Research Center, Moffett Field, CA, USA, Raimondi, Franco, Pecheur, Charles, Brat, Guillaume, Third Workshop on Model-Based Testing (MBT 2007), University College London - Department of Computer Science, UCL - FSA/INGI - Département d'ingénierie informatique, RIACS - NASA Ames Research Center, Moffett Field, CA, USA, Raimondi, Franco, Pecheur, Charles, Brat, Guillaume, and Third Workshop on Model-Based Testing (MBT 2007)

Abstract

We address the problem of verifying planning domains as used in model-based planning, for example in space missions. We propose a methodology for testing flight rules of planning domains which is self- contained, in the sense that flight rules are verified using a planner and no external tools are required. We review and analyse coverage conditions for requirements-based testing, and we reason in detail on ”Unique First Cause” (UFC) coverage for test suites. We characterise flight rules using patterns, encoded using LTL, and we provide UFC coverage for them. We then present a translation of LTL formulae into planning goals, and illustrate our approach on a case study.

Published
2007

17. Meteors: A Delivery Mechanism of Organic Matter to the Early Earth

Author

Department of Aerospace Engineering, University of Michigan, 3012 Francois-Xavier Bagnoud Building, Ann Arbor, MI, 48109-2140, NASA/Ames Research Center, Mail Stop 239-4, Moffett Field, CA, 94035, High Temperature Gasdynamics Laboratory, Stanford University, Building 520, Mechanical Engineering Department, Stanford, CA, 94305-3032, Institute for Dynamics of Geospheres RAS, Leninsky prospekt 38, bld. 6, Moscow, 117979, Russia, Ann Arbor, Jenniskens, Peter, Wilson, Mike A., Packan, Dennis, Laux, Christophe O., Kr??ger, Charles H., Boyd, Iain D., Popova, Olga P., Fonda, Mark, Department of Aerospace Engineering, University of Michigan, 3012 Francois-Xavier Bagnoud Building, Ann Arbor, MI, 48109-2140, NASA/Ames Research Center, Mail Stop 239-4, Moffett Field, CA, 94035, High Temperature Gasdynamics Laboratory, Stanford University, Building 520, Mechanical Engineering Department, Stanford, CA, 94305-3032, Institute for Dynamics of Geospheres RAS, Leninsky prospekt 38, bld. 6, Moscow, 117979, Russia, Ann Arbor, Jenniskens, Peter, Wilson, Mike A., Packan, Dennis, Laux, Christophe O., Kr??ger, Charles H., Boyd, Iain D., Popova, Olga P., and Fonda, Mark

Abstract

All potential exogenous pre-biotic matter arrived to Earth by ways of our atmosphere, where much material was ablated during a luminous phase called "meteors" in rarefied flows of high (up to 270) Mach number. The recent Leonid showers offered a first glimpse into the clusive physical conditions of the ablation process and atmospheric chemistry associated with high-speed meteors. Molecular emissions were detected that trace a meteor's brilliant light to a 4,300 K warm wake rather than to the meteor's head. A new theoretical approach using the direct simulation by Monte Carlo technique identified the source-region and demonstrated that the ablation process is critical in the heating of the meteor's wake. In the head of the meteor, organic carbon appears to survive flash heating and rapid cooling. The temperatures in the wake of the meteor are just right for dissociation of CO and the formation of more complex organic compounds. The resulting materials could account for the bulk of pre-biotic organic carbon on the early Earth at the time of the origin of life.

Published
2006

18. Behavioral responses to linear accelerations in blind goldfish

Author

Mental Health Research Institute, University of Michigan, Ann. Arbor, Mich., USA, Mental Health Research Institute, University of Michigan, Ann. Arbor, Mich., USA; NASA Ames Research Center, Moffett Field, Calif., USA, Ann Arbor, Baumgarten, R.J., Baldrighi, Giulio, Shillinger, G.L., Atema, J., Mental Health Research Institute, University of Michigan, Ann. Arbor, Mich., USA, Mental Health Research Institute, University of Michigan, Ann. Arbor, Mich., USA; NASA Ames Research Center, Moffett Field, Calif., USA, Ann Arbor, Baumgarten, R.J., Baldrighi, Giulio, Shillinger, G.L., and Atema, J.

Abstract

Blind goldfish were subjected to linear accelerations on a motor car and on a parallel swing. Moyements of the fish in a tank during the accelerations were recorded with a movie camera. During the horizontal acceleration, the fish aligns his longitudinal axis in a plane perpendicular to the direction of an apparent gravity with the fish's back pointing away from the direction of this apparent gravity vector. This is similar to the manner in which the fish usually aligns himself horizontally in response to the vertically downward terrestrial gravity and can therefore be termed???gravity reference response???. It is concluded that blind goldfish cannot distinguish between otolith displacements caused by passive tilts and equivalent otolith displacements caused by moderate inertial forces during rectilinear acceleration. With a horizontal jerk of higher magnitude, two additional responses can occur: horizontal 180?? turns following tailward jerks and straight forward darting following noseward jerks.

Published
2006

19. The distribution of ammonia and its photochemical products on Jupiter

Author

Department of Atmospheric and Oceanic Science, Space Physics Research Laboratory, The University of Michigan, Ann Arbor, Michigan 48109, USA, Department of Atmospheric and Oceanic Science, Space Physics Research Laboratory, The University of Michigan, Ann Arbor, Michigan 48109, USA; chemical Evolution Branch, NASA-Ames Research Center, California 94035., Atreya, Sushil K., Donahue, Thomas M., Kuhn, William R., Department of Atmospheric and Oceanic Science, Space Physics Research Laboratory, The University of Michigan, Ann Arbor, Michigan 48109, USA, Department of Atmospheric and Oceanic Science, Space Physics Research Laboratory, The University of Michigan, Ann Arbor, Michigan 48109, USA; chemical Evolution Branch, NASA-Ames Research Center, California 94035., Atreya, Sushil K., Donahue, Thomas M., and Kuhn, William R.

Abstract

Altitude profiles of ammonia and its photochemical products are generated in the light of the new measurements of the Jovian temperature structure, eddy transport coefficient, improved chemical scheme, and rate constants. Realistic limits are placed on the concentration of hydrazine which may participate in the recycling of ammonia on Jupiter. The maximum hydrazine ice production rate is calculated to be about 1.3 mg m-2/Jovian day. The distribution of nitrogen gas is presented with and without supersaturation of hydrazine. The nitrogen mixing ratio near the ammonia cloud top is estimated to be in the range of 10-9 to 10-11. An appreciable latitudinal variation in the ammonia concentration is expected.

Published
2006

20. Vestibular function in the space environment

Author

Department of Physiology, MHRI University of Michigan, Ann Arbor, Michigan, U.S.A., Department of Physiology, University of Mainz, Mainz, G.F.R., NASA-Ames Research Center, Moffett Field, California, U.S.A., University of Mainz, Mainz, G.F.R., Von Baumgarten, R.J., Baldrighi, Giulio, Shillinger, Jr., G.L., Harth, O., Thuemler, R., Department of Physiology, MHRI University of Michigan, Ann Arbor, Michigan, U.S.A., Department of Physiology, University of Mainz, Mainz, G.F.R., NASA-Ames Research Center, Moffett Field, California, U.S.A., University of Mainz, Mainz, G.F.R., Von Baumgarten, R.J., Baldrighi, Giulio, Shillinger, Jr., G.L., Harth, O., and Thuemler, R.

Abstract

Adaptation to the weightless state and readaptation after space flight to the 1-G environment on the ground are accompanied by various transitory symptoms of vestibular instability, kinetosis, and illusory sensations. Aside from the problem of how to treat and if possible prevent such symptoms, they offer a clue to a better understanding of normal vestibular functions. Weightlessness is a powerful new "tool" of vestibular research. Graybiel reported as early as 1952 that human subjects observed the illusion that a real target and the visual afterimage seemed to raise in the visual field during centrifugation when the subjects were looking toward the axis of rotation (oculogravic illusion). In aircraft parabolic-flight weightlessness, human subjects observed that fixed real targets appeared to have moved downward while visual afterimages appeared to have moved upward (oculoagravic illusion). It can be shown by electronystagmography as well as by a method employing double afterimages that part of this illusion is caused by eye movements that are triggered by the changing input from the otolith system. Another part of the illusion is based on a change of the subjective horizontal and must be caused by convergence of vestibular and visual impulses "behind" the eyes. This part was measured independently of the first one by using a new method. Eye movements could be prevented during these experiments by optical fixation with the right eye on a target at the end of a 24-in. long tube which was rigidly attached parallel to the longitudinal axis of an aircraft. At the same time the subject tried to line up a shorter tube, which was pivoting around his left eye, with the subjective horizon.

Published
2006

21. Assessment of Comprehensive Analysis Calculation of Airloads on Helicopter Rotors

Author

ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Yeo, Hyeonsoo, Johnson, Wayne, ELORET CORP MOFFETT FIELD CA NASA AMES RESEARCH CENTER, Yeo, Hyeonsoo, and Johnson, Wayne

Abstract

Blade section normal force and pitching moment were investigated for six rotors operating at transition and high speeds: H-34 in flight and wind tunnel, SA 330 (research Puma), SA 349/2, UH-60A full-scale and BO- 105 model (HART-I). The measured data from flight and wind tunnel tests were compared with calculations obtained using the comprehensive analysis CAMRAD II. The calculations were made using two free wake models: rolled-up and multiple-trailer with consolidation models. At transition speed, there is fair to good agreement for the blade section normal force between the test data and analysis for the H-34, research Puma and SA 349/2 with the rolled-up wake. The calculated airloads differ significantly from the measurements for the UH-60A and BO-105. Better correlation is obtained for the UH-60A and BO-105 by using the multiple-trailer with consolidation wake model. In the high speed condition, the analysis shows generally good agreement with the research Puma flight data in both magnitude and phase. However, poor agreement is obtained for the other rotors examined. The analysis shows that the aerodynamic tip design (chord length and quarter chord location) of the Puma has an important influence on the phase correlation., Presented at the American Helicopter Society Decennial Specialist's Conference on Aeromechanics (4th) held in San Francisco, CA on 21-23 January 2004. Published in the Proceedings of the American Helicopter Society Decennial Specialist's Conference on Aeromechanics (4th), 2004.

Published
2004

22. Tensor-diffusivity mixed model balancing reconstruction and truncation.

Author

UCL - FSA/MECA - Département de mécanique, NASA Ames Research Center, Moffet Field, CA 94035, USA, Université Libre de Bruxelles, Bruxelles, Belgium - Service de Physique Statistique et Plasmas, University of Twente, 7500 AE Enschede, The Netherlands - Faculty of Mathematical Sciences, Winckelmans, Grégoire, Wray, Alan A., Jeanmart, Hervé, Carati, Daniele, Geurts, Bernard J., UCL - FSA/MECA - Département de mécanique, NASA Ames Research Center, Moffet Field, CA 94035, USA, Université Libre de Bruxelles, Bruxelles, Belgium - Service de Physique Statistique et Plasmas, University of Twente, 7500 AE Enschede, The Netherlands - Faculty of Mathematical Sciences, Winckelmans, Grégoire, Wray, Alan A., Jeanmart, Hervé, Carati, Daniele, and Geurts, Bernard J.

Abstract

Large-Eddy Simulation (LES) with regular explicit filtering is investigated. The partial reconstruction of the filtered-scale stress is done through the tensordiffusivity model of Leonard: it provides for backscatter along the stretching direction(s), and for global dissipation, both also attributes of the exact filtered-scale stress. The necessary truncations (LES grid and numerical method) are responsible for an effective subgrid-scale stress. The explicit filter width must be chosen in relation to the grid size. A natural mixed model is then the tensor-diffusivity model supplemented by a dynamic Smagorinsky term. This model is reviewed, together with useful connections to other models, and is tested against Direct Numerical Simulation (DNS) of turbulent isotropic decay starting with Re f 90: LES is started from a 2563 DNS truncated to 643 or 483 and Gaussian filtered. Diagnostics in this test include energy decay, enstrophy decay and energy spectra. After an initial transient of the dynamic procedure, the mixed model is found to produce good results. The results are similar to those obtained when using the dynamic Smagorinsky model without explicit filtering. The dynamic mixed model appears as a good compromise between sufficient reconstruction of the filtered-scale stress and modeling of the subgrid-scale stress.

Published
2001

23. Generation of the organo-rare gas dications HCCRg2+(Rg = Ar and Kr) in the reaction of acetylene dications with rare gases.

Author

Daniela Ascenzi, Paolo Tosi, Jana Roithová, Claire L. RickettsPresent address: Space Science Division, NASA Ames Research Center, Moffett Field, USA, Detlef Schröder, Jessica F. Lockyear, Michael A. Parkes, and Stephen D. Price

Abstract

Using doubly ionized acetylene as a superelectrophilic reagent, the new rare-gas compounds HCCAr2+and HCCKr2+have been prepared for the first time in hyperthermal collisions of mass-selected C2H22+with neutral rare gases (Rg). However, electron transfer from the rare gas to the acetylene dication as well as proton transfer from C2H22+to the rare gas efficiently compete with formation of HCCRg2+. The computational investigations show that the formation of HCCRg2+from acetylene dication is endothermic with Rg = He, Ne, Ar and Kr and only weakly exothermic with Xe. These energetic factors, as well as the pronounced competition with the other reactive channels help to explain why HCCRg2+is only observed with Rg = Ar and Kr. [ABSTRACT FROM AUTHOR]

Published
2008
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24. Oceanic nickel depletion and a methanogen famine before the Great Oxidation Event

Author

Department of Earth and Atmospheric Sciences ; University of Alberta, Geophysical Laboratory ; Carnegie Institution of Washington, Department of Earth Sciences ; Royal Holloway University of London, School of Earth and Environment ; University of Western Australia, Laboratoire de géodynamique des chaines alpines (LGCA) ; CNRS - INSU - OSUG - Université de Savoie - Université Joseph Fourier - Grenoble I, NASA Ames Research Center (NASA - ARC) ; NASA, Department of Earth Sciences ; Laurentian University, Natural Science and Engineering Research Council of Canada (NSERC) to K.O.K.,the Canada Research Chairs Program to B.S.K., the Australian Research Council (ARC) to M.E.B., and NASA Exobiology and Evolutionary Biology Program individually to D.P. and K.Z., O. Konhauser, Kurt, Pecoits, Ernesto, Lalonde, Stefan V., Papineau, Dominic, Nisbet, Euan G., E. Barley, Mark, T. Arndt, Nicholas, Zahnle, Kevin, S. Kamber, Balz, Department of Earth and Atmospheric Sciences ; University of Alberta, Geophysical Laboratory ; Carnegie Institution of Washington, Department of Earth Sciences ; Royal Holloway University of London, School of Earth and Environment ; University of Western Australia, Laboratoire de géodynamique des chaines alpines (LGCA) ; CNRS - INSU - OSUG - Université de Savoie - Université Joseph Fourier - Grenoble I, NASA Ames Research Center (NASA - ARC) ; NASA, Department of Earth Sciences ; Laurentian University, Natural Science and Engineering Research Council of Canada (NSERC) to K.O.K.,the Canada Research Chairs Program to B.S.K., the Australian Research Council (ARC) to M.E.B., and NASA Exobiology and Evolutionary Biology Program individually to D.P. and K.Z., O. Konhauser, Kurt, Pecoits, Ernesto, Lalonde, Stefan V., Papineau, Dominic, Nisbet, Euan G., E. Barley, Mark, T. Arndt, Nicholas, Zahnle, Kevin, and S. Kamber, Balz

Abstract

International audience, It has been suggested that a decrease in atmospheric methane levels triggered the progressive rise of atmospheric oxygen, the so-called Great Oxidation Event, about 2.4 Gyr ago1. Oxidative weathering of terrestrial sulphides, increased oceanic sulphate, and the ecological success of sulphate-reducing microorganisms over methanogens has been proposed as a possible cause for the methane collapse1, but this explanation is difficult to reconcile with the rock record2,3. Banded iron formations preserve a history of Precambrian oceanic elemental abundance and can provide insights into our understanding of early microbial life and its influence on the evolution of the Earth system4,5. Here we report a decline in the molar nickel to iron ratio recorded in banded iron formations about 2.7 Gyr ago, which we attribute to a reduced flux of nickel to the oceans, a consequence of cooling upper-mantle temperatures and decreased eruption of nickel-rich ultramafic rocks at the time. We measured nickel partition coefficients between simulated Precambrian sea water and diverse iron hydroxides, and subsequently determined that dissolved nickel concentrations may have reached 400nM throughout much of the Archaean eon, but dropped below 200nM by 2.5 Gyr ago and to modern day values6 ( 9 nM) by 550 Myr ago. Nickel is a key metal cofactor in several enzymes of methanogens7 and we propose that its declinewould have stifled their activity in the ancient oceans and disrupted the supply of biogenic methane. A decline in biogenic methane production therefore could have occurred before increasing environmental oxygenation and not necessarily be related to it. The enzymatic reliance of methanogens on a diminishing supply of volcanic nickel links mantle evolution to the redox state of the atmosphere.

25. Addressing the Challenges in NextGen Decision Making

Author

United States. Department of Transportation. Federal Aviation Administration. Human Factors Division, United States. Department of Transportation. Federal Aviation Administration. Office of Aviation. Office of NextGen, Mosier, Kathleen, Fischer, Ute, Orasanu, Judith, NASA Ames Research Center, United States. Department of Transportation. Federal Aviation Administration. Human Factors Division, United States. Department of Transportation. Federal Aviation Administration. Office of Aviation. Office of NextGen, Mosier, Kathleen, Fischer, Ute, Orasanu, Judith, and NASA Ames Research Center

Abstract

DTFAWA-10-X-80005, Annex 9, NASA provided a broad overview of flight crew decision making and training challenges expected to result from the implementation of NextGen automation, including decision support automation. Recommendations included the following human factors recommendations and caveats for the design of future flight deck systems: - Pilots Need Accurate Mental Models of Automated Systems - Systems Awareness Is Key to Situation Awareness - Changes Must Be Highlighted - CRM ‘Monitor and Challenge’ Philosophy for Flight Crew Must Also Apply to Flight Deck Automation

26. The LHS 1678 system : two earth-sized transiting planets and an astrometric companion orbiting an M dwarf near the convective boundary at 20 pc

Author

Michele L. Silverstein, Joshua E. Schlieder, Thomas Barclay, Benjamin J. Hord, Wei-Chun Jao, Eliot Halley Vrijmoet, Todd J. Henry, Ryan Cloutier, Veselin B. Kostov, Ethan Kruse, Jennifer G. Winters, Jonathan M. Irwin, Stephen R. Kane, Keivan G. Stassun, Chelsea Huang, Michelle Kunimoto, Evan Tey, Andrew Vanderburg, Nicola Astudillo-Defru, Xavier Bonfils, C. E. Brasseur, David Charbonneau, David R. Ciardi, Karen A. Collins, Kevin I. Collins, Dennis M. Conti, Ian J. M. Crossfield, Tansu Daylan, John P. Doty, Courtney D. Dressing, Emily A. Gilbert, Keith Horne, Jon M. Jenkins, David W. Latham, Andrew W. Mann, Elisabeth Matthews, Leonardo A. Paredes, Samuel N. Quinn, George R. Ricker, Richard P. Schwarz, Sara Seager, Ramotholo Sefako, Avi Shporer, Jeffrey C. Smith, Christopher Stockdale, Thiam-Guan Tan, Guillermo Torres, Joseph D. Twicken, Roland Vanderspek, Gavin Wang, Joshua N. Winn, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, Bonfils, Xavier, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), University of Washington [Seattle], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)

Subjects
FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, M dwarf stars, NCAD, Astrophysics::Solar and Stellar Astrophysics, QB Astronomy, Exoplanet systems, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, QC, QB, Earth and Planetary Astrophysics (astro-ph.EP), MCC, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, 3rd-DAS, QC Physics, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Low mass stars, Transit photometry, Astrometric binary stars, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the TESS discovery of the LHS 1678 (TOI-696) exoplanet system, comprised of two approximately Earth-sized transiting planets and a likely astrometric brown dwarf orbiting a bright ($V_J$=12.5, $K_s$=8.3) M2 dwarf at 19.9 pc. The two TESS-detected planets are of radius 0.70$\pm$0.04 $R_\oplus$ and 0.98$\pm$0.06 $R_\oplus$ in 0.86-day and 3.69-day orbits, respectively. Both planets are validated and characterized via ground-based follow-up observations. HARPS RV monitoring yields 97.7 percentile mass upper limits of 0.35 $M_\oplus$ and 1.4 $M_\oplus$ for planets b and c, respectively. The astrometric companion detected by the CTIO/SMARTS 0.9m has an orbital period on the order of decades and is undetected by other means. Additional ground-based observations constrain the companion to being a high-mass brown dwarf or smaller. Each planet is of unique interest; the inner planet has an ultra-short period, and the outer planet is in the Venus zone. Both are promising targets for atmospheric characterization with the JWST and mass measurements via extreme-precision radial velocity. A third planet candidate of radius 0.9$\pm$0.1 $R_\oplus$ in a 4.97-day orbit is also identified in multi-Cycle TESS data for validation in future work. The host star is associated with an observed gap in the lower main sequence of the Hertzsprung-Russell diagram. This gap is tied to the transition from partially- to fully-convective interiors in M dwarfs, and the effect of the associated stellar astrophysics on exoplanet evolution is currently unknown. The culmination of these system properties makes LHS 1678 a unique, compelling playground for comparative exoplanet science and understanding the formation and evolution of small, short-period exoplanets orbiting low-mass stars., Published in The Astronomical Journal (31 pages, 21 figures, 11 tables, 3 appendices)

Published
2022

27. HD 207897 b:A dense sub-Neptune transiting a nearby and bright K-type star

Author

Andrew W. Mayo, Jorge Lillo-Box, George R. Ricker, C. Moutou, Stephen R. Kane, René Tronsgaard, Ashley Chontos, Allyson Bieryla, Karen A. Collins, Nicola Astudillo-Defru, Luc Arnold, Rafael Luque, Andrew W. Howard, Xavier Dumusque, S. G. Sousa, V. Bourrier, Erik Petigura, Joshua N. Winn, Magali Deleuil, Lauren M. Weiss, Enric Palle, Nuno C. Santos, Steven Giacalone, J. Rey, Damien Ségransan, Courtney D. Dressing, Paul A. Dalba, Arpita Roy, Jack Lubin, Sara Seager, Corey Beard, Natalie M. Batalha, Daniel Huber, C. E. Brasseur, T. Lopez, Howard Isaacson, Teo Mocnik, Jason D. Eastman, Peter Tenenbaum, N. Heidari, Michelle L. Hill, P. Cortés-Zuleta, O. Mousis, E. Delgado Mena, Diana Dragomir, D. W. Latham, François Bouchy, Aida Behmard, David Ehrenreich, P. A. Strøm, Fei Dai, F. Vakili, T. Forveille, Tansu Daylan, R. Vanderspek, Keivan G. Stassun, Alexandre Santerne, Melissa J. Hobson, X. Bonfils, Benjamin J. Fulton, G. Montagnier, M. Stalport, Francesco Pepe, Lars A. Buchhave, Flavien Kiefer, Nicholas Scarsdale, Lee J. Rosenthal, Vardan Adibekyan, Paul Robertson, Olivier Demangeon, J. M. Jenkins, A. Carmona, Nematollah Riazi, Stéphane Udry, Rodrigo F. Díaz, N. C. Hara, G. Gaisne, Thomas Barclay, Tara Fetherolf, X. Delfosse, L. Mignon, Sergio Hoyer, B. Courcol, J. Orell-Mique, S. Borgniet, Guillaume Hébrard, Ryan A. Rubenzahl, Lea A. Hirsch, S. Dalal, Ian J. M. Crossfield, Joseph M. Akana Murphy, L. Acuna, Isabelle Boisse, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Geneva Observatory, Université de Genève = University of Geneva (UNIGE), European Southern Observatory (ESO), Canada-France-Hawaii Telescope Corporation (CFHT), National Research Council of Canada (NRC)-Centre National de la Recherche Scientifique (CNRS)-University of Hawai'i [Honolulu] (UH), Departamento de Matemática y Fı́sica Aplicadas [Concepcion] (DMFA), Universidad Católica de la Santísima Concepción (UCSC), University of St Andrews [Scotland], Faculdade de Ciências [Lisboa], Universidade de Lisboa = University of Lisbon (ULISBOA), SwRI Planetary Science Directorate [Boulder], Southwest Research Institute [Boulder] (SwRI), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Observatoire Astronomique de l'Université de Genève (ObsGE), National Space Institute [Lyngby] (DTU Space), Danmarks Tekniske Universitet = Technical University of Denmark (DTU), SETI Institute, Instituto de Astrofísica e Ciências do Espaço (IASTRO), MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology (MIT), Department of Astronomy, University of California, Genome Sequencing Center, University of Washington School of Medicine, Universidad de Chile = University of Chile [Santiago] (UCHILE), Departamento de Quimica Inorganica e Ingenieria Quimica (Cordoba, Spain), Universidad de Córdoba = University of Córdoba [Córdoba], Peoples Friendship University of Russia [RUDN University] (RUDN), Center for Astrophysics (emeritus), Harvard-Smithsonian, Cambridge, MA, USA, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de Didactique André Revuz (LDAR (EA_4434)), Université d'Artois (UA)-Université Paris Diderot - Paris 7 (UPD7)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Instituto de Astrofisica de Canarias (IAC), Universidad de La Laguna [Tenerife - SP] (ULL), Vanderbilt University [Nashville], SLAC National Accelerator Laboratory (SLAC), Stanford University, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Peyton Hall, Clarient Pathology Services, Partenaires INRAE, Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), University of Geneva [Switzerland], Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto = University of Porto, Instituto de Astronomía y Física del Espacio [Buenos Aires] (IAFE), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Universidad de Buenos Aires [Buenos Aires] (UBA), IFP Energies nouvelles (IFPEN), Center for Space Research [Cambridge] (CSR), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and ANR-18-CE31-0019,SPlaSH,Recherche de planètes habitables avec SPIRou(2018)

Subjects
Physics, Earth and Planetary Astrophysics (astro-ph.EP), education.field_of_study, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 010308 nuclear & particles physics, Population, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Radius, Planetary system, Star (graph theory), 01 natural sciences, Exoplanet, Radial velocity, 13. Climate action, Space and Planetary Science, Planet, Neptune, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], education, 010303 astronomy & astrophysics, QB, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the discovery and characterization of a transiting sub-Neptune orbiting with a 16.20 day period around a nearby (28 pc) and bright(V=8.37) K0V star HD207897 (TOI-1611). This discovery is based on photometric measurements from the Transiting Exoplanet Survey Satellite(TESS) mission and radial velocity (RV) observations from the SOPHIE, Automated Planet Finder (APF) and HIRES high precision spectrographs. We used EXOFASTv2 for simultaneously modeling the parameters of the planet and its host star, combining photometric and RV data to determine the planetary system parameters. We show that the planet has a radius of 2.50+/-0.08 RE and a mass of either 14.4+/-1.6 ME or 15.9+/-1.6 ME with nearly equal probability; the two solutions correspond to two possibilities for the stellar activity period. Hence, the density is either 5.1+/-0.7 g cm^-3 or 5.5^{+0.8}_{-0.7} g cm^-3, making it one of the relatively rare dense sub-Neptunes. The existence of such a dense planet at only 0.12 AU from its host star is unusual in the currently observed sub-Neptune (2, Comment: 18 pages, 12 figures, 6 tables; accepted for publication in the A&A journal; comments welcome

Published
2022

28. The JCMT BISTRO Survey: Evidence for Pinched Magnetic Fields in Quiescent Filaments of NGC 1333

Author

Doi, Yasuo, Tomisaka, Kohji, Hasegawa, Tetsuo, Coudé, Simon, Arzoumanian, Doris, Bastien, Pierre, Matsumura, Masafumi, Tahani, Mehrnoosh, Sadavoy, Sarah, Hull, Charles L. H., Johnstone, Doug, Di Francesco, James, Shimajiri, Yoshito, Furuya, Ray S., Kwon, Jungmi, Tamura, Motohide, Ward-Thompson, Derek, Le Gouellec, Valentin J. M., Hoang, Thiem, Kirchschlager, Florian, Hwang, Jihye, Eswaraiah, Chakali, Koch, Patrick M., Whitworth, Anthony P., Pattle, Kate, Kwon, Woojin, Kang, Jihyun, Inutsuka, Shu-ichiro, Bourke, Tyler L., Tang, Xindi, Fanciullo, Lapo, Lee, Chang Won, Liu, Hong-Li, Lyo, A-Ran, Qiu, Keping, Lai, Shih-Ping, Department of Earth Science and Astronomy, The University of Tokyo (UTokyo), National Astronomical Observatory of Japan (NAOJ), NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université de Montréal (UdeM), Institut de Recherche sur les Exoplanètes (iREX), Kagawa University [Japan], National Research Council of Canada (NRC), Queen's University [Kingston, Canada], NRC Herzberg Astronomy and Astrophysics, Conseil National de Recherches Canada (CNRC), Tokushima University, Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy [Preston], University of Central Lancashire [Preston] (UCLAN), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Agence Spatiale Européenne = European Space Agency (ESA), Korea Astronomy and Space Science Institute (KASI), University College of London [London] (UCL), Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), Academia Sinica, School of Physics and Astronomy [Cardiff], Cardiff University, Seoul National University [Seoul] (SNU), Nagoya City University [Nagoya, Japan], Jodrell Bank Centre for Astrophysics (JBCA), University of Manchester [Manchester], Xinjiang Astronomical Observatory, Chinese Academy of Sciences [Beijing] (CAS), Yunnan Agricultural University, Nanjing University of Aeronautics and Astronautics [Nanjing] (NUAA), and National Tsing Hua University [Hsinchu] (NTHU)

Subjects
interstellar medium, Interstellar filaments (842), FOS: Physical sciences, Astronomy and Astrophysics, F500, Submillimeter astronomy (1647), Astrophysics::Cosmology and Extragalactic Astrophysics, submillimeter astronomy, Interstellar magnetic fields (845), Astrophysics - Astrophysics of Galaxies, star formation, interstellar magnetic fields, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), interstellar filaments, Polarimetry (1278), Star formation (1569), Interstellar medium (847), Astrophysics::Galaxy Astrophysics, polarimetry
Abstract

We investigate the internal 3D magnetic structure of dense interstellar filaments within NGC 1333 using polarization data at $850 \mu\mathrm{m}$ from the $B$-fields In STar-forming Region Observations survey at the James Clerk Maxwell Telescope. Theoretical models predict that the magnetic field lines in a filament will tend to be dragged radially inward (i.e., pinched) toward the central axis due to the filament's self-gravity. We study the cross-sectional profiles of the total intensity ($I$) and polarized intensity (PI) of dust emission in four segments of filaments unaffected by local star formation that are expected to retain a pristine magnetic field structure. We find that the filaments' FWHM in PI are not the same as those in $I$, with two segments being appreciably narrower in PI (FWHM ratio $\simeq 0.7-0.8$) and one segment being wider (FWHM ratio $\simeq 1.3$). The filament profiles of the polarization fraction ($P$) do not show a minimum at the spine of the filament, which is not in line with an anticorrelation between $P$ and $I$ normally seen in molecular clouds and protostellar cores. Dust grain alignment variation with density cannot reproduce the observed $P$ distribution. We demonstrate numerically that the $I$ and PI cross-sectional profiles of filaments in magnetohydrostatic equilibrium will have differing relative widths depending on the viewing angle. The observed variations of FWHM ratios in NGC 1333 are therefore consistent with models of pinched magnetic field structures inside filaments, and especially if they are magnetically near-critical or supercritical., Comment: Accepted for publication in ApJL

Published
2021

29. TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet

Author

Andrés Jordán, Sara Seager, Brett C. Addison, Maximilian N. Günther, Monika Lendl, Jack Okumura, Jorge Lillo-Box, Jon M. Jenkins, Roland Vanderspek, C. G. Tinney, Benjamin J. Fulton, Peter J. Wheatley, Erik A. Petigura, Beth A. Henderson, C. Stibbard, P. Figueira, Rafael Brahm, Eric L. N. Jensen, Michael Reefe, Cesar Briceno, Chris Stockdale, S. Hojjatpanah, Farisa Y. Morales, Alexis M. S. Smith, Caroline Dorn, Thomas Henning, Vardan Adibekyan, George W. King, Lauren M. Weiss, David R. Ciardi, Howard Isaacson, Richard P. Schwarz, Thomas Barclay, Stephen R. Kane, Keivan G. Stassun, David W. Latham, Malcolm Fridlund, Jack S. Acton, Ravit Helled, Sharon X. Wang, John Berberian, Joseph D. Twicken, J. F. Otegi, David R. Anderson, Sarah L. Casewell, Elise Furlan, Elisabeth Matthews, Johanna Teske, Rodrigo F. Díaz, Samuel Gill, Daniel Bayliss, Ian Crossfield, Peter Plavchan, Matthew W. Mengel, Joshua E. Schlieder, John F. Kielkopf, Stéphane Udry, E. Delgado Mena, H. P. Osborn, Avi Shporer, R. Cloutier, J. Villasenor, Duncan J. Wright, E. Gaidos, A. Osborn, K. I. Collins, Angelle Tanner, Nicholas M. Law, Björn Benneke, Joshua N. Winn, Fei Dai, Nicholas J. Scott, Erica J. Gonzales, Courtney D. Dressing, Sarah Ballard, Don Pollacco, Coel Hellier, Michael R. Goad, David J. Armstrong, Varoujan Gorjian, Paula Sarkis, Richard C. Kidwell, F. Zohrabi, Nuno C. Santos, David Barrado, Matthew R. Burleigh, Sergio Hoyer, Claire Geneser, Christopher J. Burke, Richard G. West, James McCormac, P. A. Strøm, Daniel Huber, Aleisha Hogan, Paul Robertson, Natalie M. Batalha, Edward M. Bryant, Liam Raynard, Karen A. Collins, Robert A. Wittenmyer, Mark E. Rose, Rachel A. Matson, Steve B. Howell, James S. Jenkins, Jose I. Vines, S. C. C. Barros, Néstor Espinoza, B. Cale, Andrew W. Howard, Diana Dragomir, Alexandre Santerne, M. Lund, Olivier Demangeon, Brendan P. Bowler, Benjamin F. Cooke, Xavier Dumusque, Andrew W. Mann, Hui Zhang, Carl Ziegler, Arpita Roy, Rosanna H. Tilbrook, Sérgio F. Sousa, George R. Ricker, Jonathan Horner, Elisa V. Quintana, Thiam-Guan Tan, Louise D. Nielsen, François Bouchy, University of New South Wales [Sydney] (UNSW), McDonald Observatory, University of Texas at Austin [Austin], Leiden Observatory [Leiden], Universiteit Leiden, Chalmers University of Technology [Gothenburg, Sweden], NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Instituto de Astrofísica e Ciências do Espaço (IASTRO), Center for Space Research [Cambridge] (CSR), Massachusetts Institute of Technology (MIT), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Département de Physique [Montréal], Université de Montréal (UdeM), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Leicester], University of Leicester, Infrared Processing and Analysis Center (IPAC), California Institute of Technology (CALTECH), Optimisation - Système - Energie (GEPEA-OSE), Laboratoire de génie des procédés - environnement - agroalimentaire (GEPEA), Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Université de Nantes (UN)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN), Institut für Virologie, Philipps University, MIT Kavli Institute for Astrophysics and Space Research, Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Department of Geology and Geophysics [Mānoa], University of Hawai‘i [Mānoa] (UHM), Universität Zürich [Zürich] = University of Zurich (UZH), Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Universidad de Chile = University of Chile [Santiago] (UCHILE), Pontificia Universidad Católica de Chile (UC), University of Louisville, Austrian Academy of Sciences (OeAW), Lund University [Lund], University of Warwick [Coventry], Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), German Aerospace Center (DLR), Swiss Bee Research Centre, Centre for Medical Image Computing (CMIC), and University College of London [London] (UCL)

Subjects
(TOI-431, planets and satellites: detection, Fundamental Parameters, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], (TOI-431, TIC 31374837), FOS: Physical sciences, Individual, Astrophysics, Q1, 01 natural sciences, Neptune, Planet, QB460, 0103 physical sciences, planets and satellites: fundamental parameters, 010303 astronomy & astrophysics, QB600, QC, 0105 earth and related environmental sciences, QB, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Super-Earth, Astronomy and Astrophysics, Planets and Satellites, Radius, Light curve, Exoplanet, Radial velocity, Photometry (astronomy), Detection, 13. Climate action, Space and Planetary Science, planets and satellites: individual: (TOI-431, TIC 31374837), Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the bright (V$_{mag} = 9.12$), multi-planet system TOI-431, characterised with photometry and radial velocities. We estimate the stellar rotation period to be $30.5 \pm 0.7$ days using archival photometry and radial velocities. TOI-431b is a super-Earth with a period of 0.49 days, a radius of 1.28 $\pm$ 0.04 R$_{\oplus}$, a mass of $3.07 \pm 0.35$ M$_{\oplus}$, and a density of $8.0 \pm 1.0$ g cm$^{-3}$; TOI-431d is a sub-Neptune with a period of 12.46 days, a radius of $3.29 \pm 0.09$ R$_{\oplus}$, a mass of $9.90^{+1.53}_{-1.49}$ M$_{\oplus}$, and a density of $1.36 \pm 0.25$ g cm$^{-3}$. We find a third planet, TOI-431c, in the HARPS radial velocity data, but it is not seen to transit in the TESS light curves. It has an $M \sin i$ of $2.83^{+0.41}_{-0.34}$ M$_{\oplus}$, and a period of 4.85 days. TOI-431d likely has an extended atmosphere and is one of the most well-suited TESS discoveries for atmospheric characterisation, while the super-Earth TOI-431b may be a stripped core. These planets straddle the radius gap, presenting an interesting case-study for atmospheric evolution, and TOI-431b is a prime TESS discovery for the study of rocky planet phase curves., Comment: 21 pages, 11 figures, 3 appendices, accepted for publication in MNRAS

Published
2021

30. Towards Uncertainty Quantification of the ONERA 7A Rotor using Comprehensive Analysis

Author

Salah El Din, Itham, Khurana, Manas, Yeo, Hyeonsoo, DAAA, ONERA, Université Paris Saclay [Meudon], ONERA-Université Paris-Saclay, NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), and United States Army (U.S. Army)

Subjects
[PHYS]Physics [physics], [SPI]Engineering Sciences [physics], RESPONSE SURFACE MODEL, MONTE CARLO, HELICOPTER ROTOR, UNCERTAINTY QUANTIFICATION, GLOBAL SENSITIVITY ANALYSIS
Abstract

International audience; The uncertainty and sensitivity of rotor blade torsion stiffness on rotor power and maximum torsion moment is studied. Comprehensive analysis tools are used to establish rotor performance and structural loads. A global-based uncertainty propagation scheme was applied using a scaling factor to uniformly induce spanwise variability in blade torsion stiffness using Monte Carlo simulations. A local-based uncertainty propagation scheme was also applied with a third-order polynomial function to induce a non-uniform distribution of material stiffness. The analysis confirmed that uncertainty in torsion stiffness has negligible impact on rotor power and maximum amplitude torsion moment along the blade span for the considered high-speed case. The analysis does confirm a pronounced effect on half peak-to-peak torsion moment at specific blade span stations where experimental measurements are available. Additionally, a sensitivity analysis using a non-uniform distribution approach with a scaling factor facilitated a comprehensive quantification of the direct and interaction effects between the uncertain parameters on the response outputs.

Published
2021

32. Plant phenology evaluation of CRESCENDO land surface models – Part 1: Start and end of the growing season

Author

D. Peano, D. Hemming, S. Materia, C. Delire, Y. Fan, E. Joetzjer, H. Lee, J. E. M. S. Nabel, T. Park, P. Peylin, D. Wårlind, A. Wiltshire, S. Zaehle, Centro Euro-Mediterraneo per i Cambiamenti Climatici [Bologna] (CMCC), Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office [Exeter], Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), NORCE Norwegian Research Center, Harvard University [Cambridge], Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Department of Physical Geography and Ecosystem Science [Lund], Lund University [Lund], Max Planck Institute for Biogeochemistry (MPI-BGC), European Project: 641816,H2020,H2020-SC5-2014-two-stage,CRESCENDO(2015), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Harvard University, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
0106 biological sciences, Biogeochemical cycle, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, Growing season, 01 natural sciences, Life, QH501-531, Leaf area index, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Southern Hemisphere, QH540-549.5, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, QE1-996.5, Ecology, Phenology, 010604 marine biology & hydrobiology, Northern Hemisphere, Geology, Vegetation, 15. Life on land, Deciduous, 13. Climate action, [SDE]Environmental Sciences, Environmental science, Physical geography
Abstract

Plant phenology plays a fundamental role in land–atmosphere interactions, and its variability and variations are an indicator of climate and environmental changes. For this reason, current land surface models include phenology parameterizations and related biophysical and biogeochemical processes. In this work, the climatology of the beginning and end of the growing season, simulated by the land component of seven state-of-the-art European Earth system models participating in the CMIP6, is evaluated globally against satellite observations. The assessment is performed using the vegetation metric leaf area index and a recently developed approach, named four growing season types. On average, the land surface models show a 0.6-month delay in the growing season start, while they are about 0.5 months earlier in the growing season end. The difference with observation tends to be higher in the Southern Hemisphere compared to the Northern Hemisphere. High agreement between land surface models and observations is exhibited in areas dominated by broadleaf deciduous trees, while high variability is noted in regions dominated by broadleaf deciduous shrubs. Generally, the timing of the growing season end is accurately simulated in about 25 % of global land grid points versus 16 % in the timing of growing season start. The refinement of phenology parameterization can lead to better representation of vegetation-related energy, water, and carbon cycles in land surface models, but plant phenology is also affected by plant physiology and soil hydrology processes. Consequently, phenology representation and, in general, vegetation modelling is a complex task, which still needs further improvement, evaluation, and multi-model comparison.

Published
2021

33. TIC 172900988: A Transiting Circumbinary Planet Detected in One Sector of TESS Data

Author

Isabelle Boisse, Greg Olmschenk, Nicholas M. Law, P. Guerra, Jessie L. Christiansen, Michael B. Lund, A. Santerne, Ward S. Howard, Richard P. Schwarz, Roland Vanderspek, Jon M. Jenkins, Steve Majewski, Joshua E. Schlieder, Mitchell Yenawine, Samuel N. Quinn, K. I. Collins, Brian P. Powell, Eric B. Ting, Joshua N. Winn, Avi Shporer, John F. Kielkopf, Ravi Kumar Kopparapu, Robert M. Quimby, Jason F. Rowe, Caleb Ben Christiansen, Ethan Kruse, Eric L. N. Jensen, Michael Fausnaugh, Matthew R. Standing, David Wood, Nader Haghighipour, Phillip J. MacQueen, David R. Ciardi, Guillaume Hébrard, Coel Hellier, Denise C. Stephens, Knicole D. Colón, Robert F. Wilson, David J. James, Pat Boyce, Serge Bergeron, Thomas Barclay, Allyson Bieryla, Guillermo Torres, Jeffrey Herman, Elisa V. Quintana, Tsevi Mazeh, Matthew J. Nelson, Dennis M. Conti, Thomas G. Beatty, Karen A. Collins, William F. Welsh, Douglas A. Caldwell, George R. Ricker, Amaury H. M. J. Triaud, Eric Agol, Joshua Pepper, S. Otero, Keivan G. Stassun, Laurance R. Doyle, Edward Wiley, Scott Dixon, Sara Seager, Daniel J. Stevens, Magali Deleuil, David W. Latham, Robert Buchheim, Eric G. Hintz, Michael Endl, Veselin B. Kostov, Jerome A. Orosz, David P. Martin, Benjamin T. Montet, Bradley S. Walter, Lalitha Sairam, Gábor Fűrész, Richard C. Kidwell, Pierre F. L. Maxted, Joseph E. Rodriguez, Gongjie Li, Joe Ulowetz, Jack J. Lissauer, Michael Richmond, Emily A. Gilbert, Felipe Murgas, Billy Quarles, William D. Cochran, Stephen R. Kane, McDonald Observatory, University of Texas at Austin [Austin], Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, Georgia Institute of Technology [Atlanta], Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), University of Washington [Seattle], NASA Goddard Space Flight Center (GSFC), Universities Space Research Association (USRA), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Center for Space Research [Cambridge] (CSR), Massachusetts Institute of Technology (MIT), Institut de Recherche sur les Exoplanètes (iREX), Université de Montréal (UdeM), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Harvard University [Cambridge]-Smithsonian Institution, Institut de Recherche Mathématique de Rennes (IRMAR), Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Rennes (ENS Rennes)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Nutrition, Métabolismes et Cancer (NuMeCan), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Genève (UNIGE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)

Subjects
Exoplanet astronomy, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Q1, Planet, Eclipsing binary stars, Binary star, QB460, Exoplanet detection methods, QA, QC, ComputingMilieux_MISCELLANEOUS, QB, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Exoplanets, Astronomy, Astronomy and Astrophysics, Exoplanet, Space and Planetary Science, Circumbinary planet, QB799, Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the first discovery of a transiting circumbinary planet detected from a single sector of TESS data. During Sector 21, the planet TIC 172900988b transited the primary star and then 5 days later it transited the secondary star. The binary is itself eclipsing, with a period of P = 19.7 days and an eccentricity of e = 0.45. Archival data from ASAS-SN, Evryscope, KELT, and SuperWASP reveal a prominent apsidal motion of the binary orbit, caused by the dynamical interactions between the binary and the planet. A comprehensive photodynamical analysis of the TESS, archival and follow-up data yields stellar masses and radii of M1 = 1.2384 +/- 0.0007 MSun and R1 = 1.3827 +/- 0.0016 RSun for the primary and M2 = 1.2019 +/- 0.0007 MSun and R2 = 1.3124 +/- 0.0012 RSun for the secondary. The radius of the planet is R3 = 11.25 +/- 0.44 REarth (1.004 +/- 0.039 RJup). The planet's mass and orbital properties are not uniquely determined - there are six solutions with nearly equal likelihood. Specifically, we find that the planet's mass is in the range of 824 < M3 < 981 MEarth (2.65 < M3 < 3.09 MJup), its orbital period could be 188.8, 190.4, 194.0, 199.0, 200.4, or 204.1 days, and the eccentricity is between 0.02 and 0.09. At a V = 10.141 mag, the system is accessible for high-resolution spectroscopic observations, e.g. Rossiter-McLaughlin effect and transit spectroscopy., 57 pages, 30 figures, 25 tables; Accepted AJ

Published
2021

34. XCO2 retrieval for GOSAT and GOSAT-2 based on the FOCAL algorithm

Author

Noël, Stefan, Reuter, Maximilian, Buchwitz, Michael, Borchardt, Jakob, Hilker, Michael, Bovensmann, Heinrich, Burrows, John P., Di Noia, Antonio, Suto, Hiroshi, Yoshida, Yukio, Buschmann, Matthias, Deutscher, Nicholas M., Feist, Dietrich G., Griffith, David W. T., Hase, Frank, Kivi, Rigel, Morino, Isamu, Notholt, Justus, Ohyama, Hirofumi, Petri, Christof, Podolske, James R., Pollard, David F., Sha, Mahesh K., Shiomi, Kei, Sussmann, Ralf, Té, Yao, Velazco, Voltaire A., Warneke, Thorsten, Institute of Environmental Physics [Bremen] (IUP), University of Bremen, Earth Observation Science Group [Leicester] (EOS), Space Research Centre [Leicester], University of Leicester-University of Leicester, Japan Aerospace Exploration Agency [Tsukuba] (JAXA), National Institute for Environmental Studies (NIES), University of Wollongong [Australia], Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Karlsruhe Institute of Technology (KIT), Finnish Meteorological Institute (FMI), NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), National Institute of Water and Atmospheric Research [Lauder] (NIWA), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
OCO-2, Earth sciences, remote sensing, [SDU]Sciences of the Universe [physics], satellite, ddc:550, TCCON, XCO2, retrieval, GOSAT
Abstract

Since 2009, the Greenhouse gases Observing SATellite (GOSAT) performs radiance measurements in the shortwave-infrared (SWIR) spectral region. From February 2019 onward, data from GOSAT-2 are also available. We present first results from the application of the Fast atmOspheric traCe gAs retrieval (FOCAL) algorithm to derive column-averaged dry-air mole fractions of carbon dioxide (XCO2) from GOSAT and GOSAT-2 radiances and their validation. FOCAL has initially been developed for OCO-2 XCO2 retrievals and allows simultaneous retrievals of several gases over both land and ocean. Because FOCAL is accurate and numerically very fast it is currently considered as a candidate algorithm for the forthcoming European anthropogenic CO2 Monitoring (CO2M) mission, to be launched in 2025. We present the adaptation of FOCAL to GOSAT and discuss the changes made and GOSAT specific additions. This includes particularly modifications in pre-processing (e.g. cloud detection) and post-processing (bias correction and filtering). A feature of the new application of FOCAL to GOSAT/GOSAT-2 is the independent use of both S and P polarisation spectra in the retrieval. This is not possible for OCO-2, which measures only one polarisation direction. Additionally, we make use of GOSAT’s wider spectral coverage compared to OCO-2 and derive not only XCO2, water vapour (H2O) and solar induced fluorescence (SIF) but also methane (XCH4), with the potential for further atmospheric constituents and parameters like semiheavy water vapour (HDO) and (in the case of GOSAT-2) also carbon monoxide (CO) total columns and possibly nitrous oxide (XN2O). Here, we concentrate on the new FOCAL XCO2 data products. We describe the generation of the products as well as applied filtering and bias correction procedures. GOSAT-FOCAL XCO2 data have been produced for the time interval 2009 to 2019. Comparisons with other independent GOSAT data sets reveal an agreement of long-term temporal variations within about 1 ppm over one decade; differences in seasonal variations of about 0.5 ppm are observed. Furthermore, we obtain a mean regional bias of the new GOSAT-FOCAL product to the ground based Total Carbon Column Observing Network (TCCON) of 0.56 ppm with a mean scatter of 1.89 ppm. The GOSAT-2-FOCAL XCO2 product is generated in a similar way as the GOSAT-FOCAL product, but with adapted settings. All GOSAT-2 data until end of 2019 have been processed. Because of this limited time interval, the GOSAT-2 results are considered to be preliminary only, but first comparisons show that these data compare well with the GOSAT-FOCAL results.

Published
2020

35. Understanding polarized dust emission from $\rho$ Ophiuchi A in light of grain alignment and disruption by radiative torques

Author

William T. Reach, Le Ngoc Tram, Thiem Hoang, Pierre Lesaffre, Hye Seung Lee, Archana Soam, Fabio P. Santos, Antoine Gusdorf, Korea Astronomy and Space Science Institute (KASI), Okayama University, NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Astrophysique, Laboratoire de physique de l'ENS - ENS Paris (LPENS (UMR_8023)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Laboratoire de physique de l'ENS - ENS Paris (LPENS), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
[PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 010504 meteorology & atmospheric sciences, Polarimetry, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Interstellar dust (836), 0103 physical sciences, Radiative transfer, Astrophysics::Solar and Stellar Astrophysics, Interstellar radiation field (852), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Cosmic dust, [PHYS]Physics [physics], Physics, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, Interstellar medium, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, Polarimetry (1278), Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Interstellar dust extinction (837), Interstellar medium (847), Dust emission
Abstract

The alignment of dust grains with the ambient magnetic field produces polarization of starlight as well as thermal dust emission. Using the archival SOFIA/HAWC+ polarimetric data observed toward $\rho$ Ophiuchus (Oph) A cloud hosted by a B association star at 89 $\mu$m and 154 $\mu$m, we find that the fractional polarization of thermal dust emission first increases with the grain temperature and then decreases once the grain temperature exceeds $\simeq$ 25-32 K. The latter trend differs from the prediction of the popular RAdiative Torques (RATs) alignment theory which implies a monotonic increase of the polarization fraction with the grain temperature. We perform numerical modeling of polarized dust emission for the $\rho$ Oph-A cloud and calculate the degree of dust polarization by simultaneously considering the dust grain alignment and rotational disruption by RATs. Our modeling results could successfully reproduce both the rising and declining trends of the observational data. Moreover, we show that the alignment of only silicate grains or a mixture of silicate-carbon grains within a composite structure can reproduce the observational trends, assuming that all dust grains follow a power-law size distribution. Although there are a number of simplifications and limitations to our modeling, our results suggest grains in $\rho$ Oph-A cloud have a composite structure, and the grain size distribution has steeper slope than the standard size distribution for the interstellar medium. Combination of SOFIA/HAWC+ data with JCMT observations 450 $\mu$m and 850 $\mu$m would be useful to test the proposed scenario based on grain alignment and disruption by RATs., Comment: 14 pages, 12 figures, 1 table, accepted to ApJ

Published
2020

36. Production and excitation of molecules by dissipation of two-dimensional turbulence

Author

N Dzyurkevich, Le Ngoc Tram, E. Falgarone, F Levrier, Valeska Valdivia, P Todorov, A Lehmann, A. Gusdorf, B Godard, P Lesaffre, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Astrophysique, Laboratoire de physique de l'ENS - ENS Paris (LPENS), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-École normale supérieure - Paris (ENS Paris), Laboratoire Aimé Cotton (LAC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Institute for Theoretical Astrophysics [Heidelberg], Heidelberg University, University of sciences and technologies of hanoi (USTH), NASA Ames Research Center (ARC), Laboratoire de physique de l'ENS - ENS Paris (LPENS (UMR_8023)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Universität Heidelberg [Heidelberg], Stratospheric Observatory for Infrared Astronomy (SOFIA), NASA Ames Research Center (ARC)-Universities Space Research Association (USRA)-Deutsches Zentrum für Luft- und Raumfahrt [Stuttgart] (DLR), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris)

Subjects
Shock wave, Astrochemistry, 01 natural sciences, Molecular physics, ISM: kinematicsand dynamics, 0103 physical sciences, 010303 astronomy & astrophysics, ISM: kinematics and dynamics, Physics, [PHYS]Physics [physics], 010308 nuclear & particles physics, Turbulence, astrochemistry, diffusion, Astronomy and Astrophysics, shock waves, Dissipation, ISM: molecules, Interstellar medium, 13. Climate action, Space and Planetary Science, Excited state, hydrodynamics, Dissipative system, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Excitation
Abstract

The interstellar medium (ISM) is typically a hostile environment: cold, dilute and irradiated. Nevertheless, it appears very fertile for molecules. The localized heating resulting from turbulence dissipation is a possible channel to produce and excite molecules. However, large-scale simulations cannot resolve the dissipative scales of the ISM. Here, we present two-dimensional small-scale simulations of decaying hydrodynamic turbulence using the chemses code, with fully resolved viscous dissipation, time-dependent heating, cooling, chemistry and excitation of a few rotational levels of H2. We show that molecules are produced and excited in the wake of strong dissipation ridges. We carefully identify shocks and we assess their statistics and contribution to the molecular yields and excitation. We find that the formation of molecules is strongly linked to increased density as a result of shock compression and to the opening of endothermic chemical routes because of higher temperatures. We identify a new channel for molecule production via H2 excitation, illustrated by CH+ yields in our simulations. Despite low temperatures and the absence of magnetic fields (favouring CH+ production through ion-neutral velocity drifts), the excitation of the first few rotational levels of H2 shrinks the energy gap to form CH+. The present study demonstrates how dissipative chemistry can be modelled by statistical collections of one-dimensional steady-state shocks. Thus, the excitation of higher J levels of H2 is likely to be a direct signature of turbulence dissipation, and an indirect probe for molecule formation. We hope these results will help to bring new tools and ideas for the interpretation of current observations of H2 rotational lines carried out using the Stratospheric Observatory for Infrared Astronomy (SOFIA), and pave the way for a better understanding of the high-resolution mapping of H2 emission by future instruments, such as theJames Webb Space Telescope and the Space Infrared Telescope for Cosmology and Astrophysics.

Published
2020

37. Detection of Polarization due to Cloud Bands in the Nearby Luhman 16 Brown Dwarf Binary

Author

Mark S. Marley, Jos de Boer, Arthur Vigan, Tiffany Kataria, Julien Girard, Dimitri Mawet, Theodora Karalidi, Sasha Hinkley, Sujan Sengupta, Frans Snik, Maxwell A. Millar-Blanchaer, Rob G. van Holstein, Rebecca Jensen-Clem, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Southern Observatory (ESO), NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Caltech Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), Stony Brook University [SUNY] (SBU), State University of New York (SUNY), Universiteit Leiden, Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), School of Physics and Astronomy [Exeter], University of Exeter, Leiden University, University of California [Berkeley], University of California-University of California, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and California Institute of Technology (CALTECH)-NASA

Subjects
Physics, Very Large Telescope, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Linear polarization, Brown dwarf, Astronomy and Astrophysics, Astrophysics, Polarization (waves), 01 natural sciences, Stars, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Binary star, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Cosmic dust
Abstract

Brown dwarfs exhibit patchy or spatially varying banded cloud structures that are inferred through photometric and spectroscopic variability modeling techniques. However, these methods are insensitive to rotationally invariant structures, such as the bands seen in Jupiter. Here, we present H-band Very Large Telescope/NaCo linear polarization measurements of the nearby Luhman 16 L/T transition binary, which suggest that Luhman 16A exhibits constant longitudinal cloud bands. The instrument was operated in pupil tracking mode, allowing us to unambiguously distinguish between a small astrophysical polarization and the ∼2% instrumental linear polarization. We measure the degree and angle of linear polarization of Luhman 16A and B to be p A = 0.031% ± 0.004% and ψ A = −32° ± 4°, and p B = 0.010% ± 0.004% and , respectively. Using known physical parameters of the system, we demonstrate that an oblate homogeneous atmosphere cannot account for the polarization measured in Luhman 16A, but could be responsible for that of the B component. Through a nonexhaustive search of banded cloud morphologies, we demonstrate a two-banded scenario that can achieve a degree of linear polarization of p = 0.03% and conclude that the measured polarization of the A component must be predominantly due to cloud banding. For Luhman 16B, either oblateness or cloud banding could be the dominant source of the measured polarization. The misaligned polarization angles of the two binary components tentatively suggest spin–orbit misalignment. These measurements provide new evidence for the prevalence of cloud banding in brown dwarfs while at the same time demonstrating a new method—complementary to photometric and spectroscopic variability methods—for characterizing the cloud morphologies of substellar objects without signs of variability.

Published
2020

38. Interstellar anatomy of the TeV gamma-ray peak in the IC443 supernova remnant

Author

Maryvonne Gerin, F. Louvet, Le Ngoc Tram, Alberto Noriega-Crespo, Rolf Güsten, Marco Padovani, Pierre Guillard, Antoine Gusdorf, Pierre Lesaffre, Denise Riquelme, Alexandre Marcowith, P. Dell'Ova, A. Lehmann, Martin Houde, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Astrophysique, Laboratoire de physique de l'ENS - ENS Paris (LPENS), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Space Telescope Science Institute (STSci), Stratospheric Observatory for Infrared Astronomy (SOFIA), Deutsches Zentrum für Luft- und Raumfahrt [Stuttgart] (DLR)-NASA Ames Research Center (ARC)-Universities Space Research Association (USRA), Institut de Recherche en Immunologie et en Cancérologie [UdeM-Montréal] (IRIC), Université de Montréal (UdeM), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Ecole Normale Supérieure, Université Marien Ngouabi, Storengy France, Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Département de Physique de l'ENS-PSL, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Département de Physique de l'ENS-PSL, Max-Planck-Institut für Radioastronomie (MPIFR), NASA Ames Research Center (ARC)-Universities Space Research Association (USRA)-Deutsches Zentrum für Luft- und Raumfahrt [Stuttgart] (DLR), University of Western Ontario (UWO), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de l'ENS - ENS Paris (LPENS (UMR_8023)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)

Subjects
ISM: individual objects: IC443, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, cosmic rays, 0103 physical sciences, Protostar, Astrophysics::Solar and Stellar Astrophysics, Supernova remnant, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ISM: supernova remnants, Physics, ISM: kinematics and dynamics, High Energy Astrophysical Phenomena (astro-ph.HE), stars: formation, 010308 nuclear & particles physics, Star formation, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Interstellar medium, Supernova, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - High Energy Astrophysical Phenomena
Abstract

Context.Supernova remnants (SNRs) represent a major feedback source from stars in the interstellar medium of galaxies. During the latest stage of supernova explosions, shock waves produced by the initial blast modify the chemistry of gas and dust, inject kinetic energy into the surroundings, and may alter star formation characteristics. Simultaneously,γ-ray emission is generated by the interaction between the ambient medium and cosmic rays (CRs), including those accelerated in the early stages of the explosion.Aims.We study the stellar and interstellar contents of IC443, an evolved shell-type SNR at a distance of 1.9 kpc with an estimated age of 30 kyr. We aim to measure the mass of the gas and characterize the nature of infrared point sources within the extended G region, which corresponds to the peak ofγ-ray emission detected by VERITAS andFermi.Methods.We performed 10′ × 10′ mapped observations of12CO,13COJ= 1–0,J= 2–1, andJ= 3–2 pure rotational lines, as well as C18OJ= 1–0 andJ= 2–1 obtained with the IRAM 30 m and APEX telescopes over the extent of theγ-ray peak to reveal the molecular structure of the region. We first compared our data with local thermodynamic equilibrium models. We estimated the optical depth of each line from the emission of the isotopologs13CO and C18O. We used the population diagram and large velocity gradient assumption to measure the column density, mass, and kinetic temperature of the gas using12CO and13CO lines. We used complementary data (stars, gas, and dust at multiple wavelengths) and infrared point source catalogs to search for protostar candidates.Results.Our observations reveal four molecular structures: a shocked molecular clump associated with emission lines extending between −31 and 16 km s−1, a quiescent, dark cloudlet associated with a line width of ~2 km s−1, a narrow ring-like structure associated with a line width of ~1.5 km s−1, and a shocked knot. We measured a total mass of ~230, ~90, ~210, and ~4M⊙, respectively, for the cloudlet, ring-like structure, shocked clump, and shocked knot. We measured a mass of ~1100M⊙throughout the rest of the field of observations where an ambient cloud is detected. We found 144 protostar candidates in the region.Conclusions.Our results emphasize how the mass associated with the ring-like structure and the cloudlet cannot be overlooked when quantifying the interaction of CRs with the dense local medium. Additionally, the presence of numerous possible protostars in the region might represent a fresh source of CRs, which must also be taken into account in the interpretation ofγ-ray observationsin this region.

Published
2020
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39. A Search for Polarized Thermal Emission from Directly Imaged Exoplanets and Brown Dwarf Companions to Nearby Stars

Author

Jos de Boer, R. Jensen-Clem, Maxwell A. Millar-Blanchaer, Sloane Wiktorowicz, James R. Graham, Mark S. Marley, Julien Girard, Marshall D. Perrin, Sujan Sengupta, Frans Snik, Robert J. De Rosa, Rob G. van Holstein, Sasha Hinkley, Bruce Macintosh, Arthur Vigan, Dimitri Mawet, Brendan P. Bowler, Justin R. Crepp, Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley], University of California-University of California, Caltech Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Leiden University, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), School of Physics and Astronomy [Exeter], University of Exeter, University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), and Universiteit Leiden

Subjects
Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Stellar atmosphere, Brown dwarf, Astronomy, Astronomy and Astrophysics, Thermal emission, 01 natural sciences, Exoplanet, 010309 optics, Stars, Space and Planetary Science, 0103 physical sciences, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2020
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41. Contributions to the Sixth Drag Prediction Workshop Using Structured, Overset Grid Methods

Author

Coder, James G., Pulliam, Thomas H., Sclafani, Anthony J., Vassberg, John C., Coder, James, Hue, David, Kenway, Gaetan, Pulliam, Thomas, Sclafani, Anthony, Serrano, Leonel, Vassberg, John, The University of Tennessee [Knoxville], ONERA - The French Aerospace Lab [Meudon], ONERA-Université Paris Saclay (COmUE), University of Michigan [Ann Arbor], University of Michigan System, NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), and Boeing Commercial Airplanes

Subjects
Lift coefficient, Nacelle, Computer science, DPW, Aerospace Engineering, 02 engineering and technology, Computational fluid dynamics, 01 natural sciences, DRAG, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], 010305 fluids & plasmas, Computational science, Physics::Fluid Dynamics, 0203 mechanical engineering, 0103 physical sciences, ComputingMethodologies_COMPUTERGRAPHICS, 020301 aerospace & aeronautics, Adaptive mesh refinement, business.industry, Turbulence modeling, Mechanics, CRM, Flow (mathematics), Drag, Astrophysics::Earth and Planetary Astrophysics, OVERSET GRID, business, Reynolds-averaged Navier–Stokes equations
Abstract

International audience; Structured-grid solutions obtained for the NASA Common Research Model for the Sixth AIAA Computational Fluid Dynamics Drag Prediction Workshop are detailed. Three different flow solvers were used among the contributors, and the numerical methodologies and turbulence modeling strategies employed by each code are described. Key results for all authors include grid convergence studies for the drag increment of a nacelle and pylon added to a wing–body configuration and a buffet study accounting for static aeroelastic deformation. Additional studies performed include feature-based adaptive mesh refinement and higher-order convective flux discretization, among others.

Published
2018

45. Sodium and Potassium Signatures of Volcanic Satellites Orbiting Close-in Gas Giant Exoplanets

Author

Christoph Mordasini, Diana Gamborino, Carl Schmidt, Brice-Olivier Demory, Robert E. Johnson, Chenliang Huang, Apurva Oza, Emmanuel Lellouch, Prabal Saxena, Nicolas Thomas, Aurélien Wyttenbach, Nicholas M. Schneider, Arielle Moullet, David Dubois, Andrea Gebek, Universität Bern [Bern], University of Virginia [Charlottesville], New York University [New York] (NYU), NYU System (NYU), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Boston University [Boston] (BU), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], University of Nevada [Las Vegas] (WGU Nevada), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Leiden University, NASA Goddard Space Flight Center (GSFC), NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)

Subjects
Solar System, 010504 meteorology & atmospheric sciences, 530 Physics, Gas giant, FOS: Physical sciences, Astrophysics, Orbital decay, 7. Clean energy, 01 natural sciences, Jupiter, Atmosphere, 0103 physical sciences, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 520 Astronomy, Astronomy and Astrophysics, 620 Engineering, Exoplanet, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Equivalent width, Astrophysics - Earth and Planetary Astrophysics, Exosphere
Abstract

Extrasolar satellites are generally too small to be detected by nominal searches. By analogy to the most active body in the Solar System, Io, we describe how sodium (Na I) and potassium (K I) $\textit{gas}$ could be a signature of the geological activity venting from an otherwise hidden exo-Io. Analyzing $\sim$ a dozen close-in gas giants hosting robust alkaline detections, we show that an Io-sized satellite can be stable against orbital decay below a planetary tidal $\mathcal{Q}_p \lesssim 10^{11}$. This tidal energy is focused into the satellite driving a $\sim 10^{5 \pm 2}$ higher mass loss rate than Io's supply to Jupiter's Na exosphere, based on simple atmospheric loss estimates. The remarkable consequence is that several exo-Io column densities are on average $\textit{more than sufficient}$ to provide the $\sim$ 10$^{10 \pm 1}$ Na cm$^{-2}$ required by the equivalent width of exoplanet transmission spectra. Furthermore, the benchmark observations of both Jupiter's extended ($\sim 1000$ R$_J$) Na exosphere and Jupiter's atmosphere in transmission spectroscopy yield similar Na column densities that are purely exogenic in nature. As a proof of concept, we fit the "high-altitude" Na at WASP 49-b with an ionization-limited cloud similar to the observed Na profile about Io. Moving forward, we strongly encourage time-dependent ingress and egress monitoring along with spectroscopic searches for other volcanic volatiles., Comment: 23 pages, 5 figures, accepted to ApJ

Published
2019

46. Three Red Suns in the Sky: A Transiting, Terrestrial Planet in a Triple M-dwarf System at 6.9 pc

Author

Winters, Jennifer G., Medina, Amber A., Irwin, Jonathan M., Charbonneau, David, Astudillo-Defru, Nicola, Horch, Elliott P., Eastman, Jason D., Halley Vrijmoet, Eliot, Henry, Todd J., Diamond-Lowe, Hannah, Winston, Elaine, Barclay, Thomas, Bonfils, Xavier, Ricker, George R., Vanderspek, Roland, Latham, David W., Seager, Sara, Winn, Joshua N., Jenkins, Jon M., Udry, Stéphane, Twicken, Joseph D., Teske, Johanna K., Tenenbaum, Peter, Pepe, Francesco, Murgas, Felipe, Muirhead, Philip S., Mink, Jessica, Lovis, Christophe, Levine, Alan M., Lépine, Sébastien, Jao, Wei-Chun, Henze, Christopher E., Furész, Gábor, Forveille, Thierry, Figueira, Pedro, Esquerdo, Gilbert A., Dressing, Courtney D., Diaz, Rodrigo F., Delfosse, Xavier, Burke, Christopher J., Bouchy, François, Berlind, Perry, Almenara, Jose-Manuel, Winters, Jennifer, Medina, Amber, Irwin, Jonathan, Horch, Elliott, Eastman, Jason, Vrijmoet, Eliot Halley, Henry, Todd, Ricker, George, Latham, David, Winn, Joshua, Jenkins, Jon, Twicken, Joseph, Teske, Johanna, Muirhead, Philip, Levine, Alan, Henze, Christopher, Esquerdo, Gilbert, Dressing, Courtney, DIAZ, Rodrigo, Burke, Christopher, NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Center for Space Research [Cambridge] (CSR), Massachusetts Institute of Technology (MIT), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Optimisation - Système - Energie (GEPEA-OSE), Laboratoire de génie des procédés - environnement - agroalimentaire (GEPEA), Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidad de Concepción [Chile], Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Smithsonian Institution-Harvard University [Cambridge], Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
planets and satellites: detection, 010504 meteorology & atmospheric sciences, Brown dwarf, FOS: Physical sciences, Astrophysics, 01 natural sciences, stars: individual: LTT 1445, Primary (astronomy), Planet, stars: low-mass, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), binaries: close, Center (category theory), Astronomy and Astrophysics, Orbital period, Exoplanet, Radial velocity, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Terrestrial planet, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the discovery from TESS data of LTT 1445Ab. At a distance of 6.9 parsecs, it is the second nearest transiting exoplanet system found to date, and the closest one known for which the primary is an M dwarf. The host stellar system consists of three mid-to-late M dwarfs in a hierarchical configuration, which are blended in one TESS pixel. We use data from MEarth and results from the SPOC DV report to determine that the planet transits the primary star in the system. The planet has a radius 1.38 R_Earth, an orbital period of 5.35882 days, and an equilibrium temperature of 433 K. With radial velocities from HARPS, we place a three-sigma upper mass limit of 8.4 M_Earth on the candidate. The planet provides one of the best opportunities to date for the spectroscopic study of the atmosphere of a terrestrial world. The presence of stellar companions of similar spectral type may facilitate such ground-based studies by providing a calibration source to remove telluric variations. In addition, we present a detailed characterization of the host stellar system. We use high-resolution spectroscopy and imaging to rule out the presence of any other close stellar or brown dwarf companions. Nineteen years of photometric monitoring of A and BC indicates a moderate amount of variability, in agreement with the observed low-level, short-term variability in the TESS light curve data. We derive a preliminary astrometric orbit for the BC pair that reveals an edge-on and eccentric configuration. The presence of a transiting planet in this system raises the possibility that the entire system is co-planar, which implies that the system may have formed from the early fragmentation of an individual protostellar core., Comment: Accepted to AJ; 21 pages, 8 tables, 7 figures

Published
2019

47. Haze formation in the atmospheres of super-Earths and mini-Neptunes

Author

Hörst, Sarah, HE, Chao, Lewis, Nikole, Moses, Julianne, Kempton, Eliza, McGuiggan, Patricia, Marley, Mark, Morley, Caroline, Valenti, Jeff, Vuitton, Véronique, Yu, Xinting, Johns Hopkins University (JHU), Space Telescope Science Institute (STSci), NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astrophysics::Earth and Planetary Astrophysics, Physics::Atmospheric and Oceanic Physics
Abstract

International audience; We have conducted a series of laboratory atmosphere simulation experiments to understand the chemistry occurring in the diversity of atmospheres expected for super-Earths and mini-Neptunes, including processes that may lead to the formation of hazes in these atmospheres. We will present the results of these experiments including production rates, particle size distributions, and gas phase chemistry.

Published
2019

48. The Hubble Space Telescope PanCET Program: Exospheric Mg ii and Fe ii in the Near-ultraviolet Transmission Spectrum of WASP-121b Using Jitter Decorrelation

Author

Gregory W. Henry, Hannah R. Wakeford, Panayotis Lavvas, Mark S. Marley, Lars A. Buchhave, David Ehrenreich, Jorge Sanz-Forcada, Alain Lecavelier des Etangs, Antonio García Muñoz, Jessica Spake, Gilda E. Ballester, Nikolay Nikolov, Thomas Mikal-Evans, Tiffany Kataria, David K. Sing, Vincent Bourrier, Lotfi Ben-Jaffel, Drake Deming, Mercedes Lopez-Morales, Nikole K. Lewis, School of Physics and Astronomy [Exeter], University of Exeter, Groupe de spectrométrie moléculaire et atmosphérique (GSMA), Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Stiftelsen for INdustriell og TEknisk Forskning Digital [Trondheim] (SINTEF Digital), University of Geneva [Switzerland], Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), University of Maryland [College Park], University of Maryland System, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Space Telescope Science Institute (STSci), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Zentrum für Astronomie und Astrophysik [Berlin] (ZAA), Technische Universität Berlin (TU), Tennessee State University, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), NASA Goddard Space Flight Center (GSFC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Stony Brook University [SUNY] (SBU), State University of New York (SUNY), and Smithsonian Institution-Harvard University [Cambridge]

Subjects
010504 meteorology & atmospheric sciences, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, spectroscopic [Techniques], Planet, 0103 physical sciences, Hot Jupiter, Astrophysics::Solar and Stellar Astrophysics, Roche lobe, Absorption (logic), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Line (formation), Physics, planets and satellites: atmospheres, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], photometric [Techniques], Astronomy and Astrophysics, Light curve, techniques photometric, individual (WASP-121) [Stars], 13. Climate action, Space and Planetary Science, atmospheres [Planets and satellites], Astrophysics::Earth and Planetary Astrophysics, techniques: spectroscopic, Exosphere, stars: individual (WASP-121)
Abstract

We present Hubble Space Telescope (HST) near-ultraviolet (NUV) transits of the hot Jupiter WASP-121b, acquired as part of the PanCET program. Time-series spectra during two transit events were used to measure the transmission spectra between 2280 and 3070 Å at a resolution of 30,000. Using HST data from 61 Space Telescope Imaging Spectrograph visits, we show that data from HST's Pointing Control System can be used to decorrelate the instrument systematic errors (jitter decorrelation), which we used to fit the WASP-121b light curves. The NUV spectra show very strong absorption features, with the NUV white light curve found to be larger than the average optical and near-infrared value at 6σ confidence. We identify and spectrally resolve absorption from the Mg ii doublet in the planetary exosphere at a 5.9σ confidence level. The Mg ii doublet is observed to reach altitudes of R pl/R star = 0.284 ± 0.037 for the 2796 Å line and 0.242 ± 0.0431 for the 2804 Å line, which exceeds the Roche lobe size as viewed in transit geometry (R eqRL/R star = 0.158). We also detect and resolve strong features of the Fe ii UV1 and UV2 multiplets, and observe the lines reaching altitudes of R pl/R star ≈ 0.3. At these high altitudes, the atmospheric Mg ii and Fe ii gas is not gravitationally bound to the planet, and these ionized species may be hydrodynamically escaping or could be magnetically confined. Refractory Mg and Fe atoms at high altitudes also indicate that these species are not trapped into condensate clouds at depth, which places constraints on the deep interior temperature.

Published
2019

49. Modeling rotational disruption of grains and microwave emission from spinning dust in AGB envelopes

Author

Archana Soam, Thiem Hoang, Pierre Lesaffre, William T. Reach, Le Ngoc Tram, NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Korea Astronomy and Space Science Institute (KASI), Okayama University, Observatoire de Paris, Université Paris sciences et lettres (PSL), Astrophysique, Laboratoire de physique de l'ENS - ENS Paris (LPENS (UMR_8023)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de physique de l'ENS - ENS Paris (LPENS), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Sorbonne Université (SU)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Radio telescope, Asymptotic giant branch stars, 0103 physical sciences, Thermal, Radiative transfer, Asymptotic giant branch, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Spinning, Interstellar extinction, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Spinning dust, Interstellar dust extinction, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Circumstellar envelopes, Stars, Radio continuum emission, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Microwave
Abstract

Radio observations of some Asymptotic Giant Branch (AGB) star envelopes show the excess emission at frequencies below 100 GHz which cannot be explained by thermal dust emission (hereafter anomalous microwave emission-AME). Moreover, AGB envelopes are a common place where gas molecules condense to form nanoparticles (e.g., polycyclic aromatic hydrocarbons) and large grains. In this paper, we will study whether electric dipole emission from rapidly spinning nanoparticles can reproduce the AME observed toward AGB stars. To properly model the size distribution of nanoparticles in the AGB envelope, we take into account both the increase of nanoparticles due to rotational disruption of large grains spun-up by radiative torques and the decrease of smallest nanoparticles due to rotational disruption driven by stochastic gas collisions. We then perform detailed modeling of microwave emission from rapidly spinning nanoparticles from both C-rich and O-rich AGB envelopes using the grain size distribution constrained by rotational disruption. We find that spinning dust emission is dominant over thermal dust emission at frequencies below 100 GHz. We attempt to fit the observational data of AME using our spinning dust model and demonstrate that spinning dust can reproduce the observed AME in six AGB stars. Finally, we discuss that microwave emission from spinning dust in AGB envelopes could be observed with high-resolution upcoming radio telescopes such as ngVLA and ALMA Band 1. This would be a major leap for understanding AGB envelopes, formation, evolution, and internal structures of dust. Observations would help to distinguish the carrier of AME from comparing C-rich to O-rich stars, because PAHs are formed in C-rich AGB stars while silicates are formed in O-rich stars., 15 pages, 10 figures, and 2 tables

Published
2019

50. Community Involvement in the WFIRST Exoplanet Microlensing Survey

Author

Bennett, David, Akeson, Rachel, Barclay, Thomas, Beaulieu, Jean-Phillipe, Bhattacharya, Aparna, Boyd, Padi, Bozza, Valerio, Bryden, Geoffrey, Calchi Novati, Sebastiano, Colon, Knicole, Gaudi, B. Scott, Henderson, Calen B., Hirao, Yuki, Jacklin, Savannah, Koshimoto, Naoki, Lu, Jessica, Penny, Matthew, Poleski, Radek, Quintana, Elisa, Ranc, Clément, Sahu, Kailash C., Street, Rachel, Sumi, Takahiro, Suzuki, Daisuke, Yee, Jennifer, Aston Business School, Aston University [Birmingham], NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy [Berkeley], University of California [Berkeley], University of California-University of California, and goddard space

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

WFIRST is NASA's first flagship mission with predefined core core science programs. We present a set of high level data products that will enable broad participation in the science of the exoplanet microlensing survey and a community science team concept that will allow broad community involvement in the survey development and scientific output.

Published
2019

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