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1. Strengthening Health Systems To Face Pandemics: Subnational Policy Responses To COVID-19 In Latin America

Author: Knaul, F.M., Touchton, M.M., Arreola-Ornelas, H., Calderon-Anyosa, R., Otero-Bahamón, S., Hummel, C., Pérez-Cruz, P., Porteny, T., Patino, F., Atun, R., Garcia Funegra, Patricia Jannet, Insua, J., Mendez, O., Undurraga, E., Boulding, C., Nelson-Nuñez, J., Velasco Guachalla, V.X., and Sanchez-Talanquer, M.
Subjects: Latin America, Policy, SARS-CoV-2, pandemic, COVID-19, Humans, epidemiology, prevention and control, human, Pandemics, South and Central America
Abstract: Nonpharmaceutical interventions such as stay-at-home orders continue to be the main policy response to the COVID-19 pandemic in countries with limited or slow vaccine rollout. Often, nonpharmaceutical interventions are managed or implemented at the subnational level, yet little information exists on within-country variation in nonpharmaceutical intervention policies. We focused on Latin America, a COVID-19 epicenter, and collected and analyzed daily subnational data on public health measures in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Mexico, and Peru to compare within- and across-country nonpharmaceutical interventions. We showed high heterogeneity in the adoption of these interventions at the subnational level in Brazil and Mexico; consistent national guidelines with subnational heterogeneity in Argentina and Colombia; and homogeneous policies guided by centralized national policies in Bolivia, Chile, and Peru. Our results point to the role of subnational policies and governments in responding to health crises. We found that subnational responses cannot replace coordinated national policy. Our findings imply that governments should focus on evidence-based national policies while coordinating with subnational governments to tailor local responses to changing local conditions.
Published: 2022

2. A bottom-up practitioner-derived set of Essential Variables for Protected Area management

Author: Hummel H.[1, Kalle V.[1], Bienfait L.[1], Boyer Y.[3], Heurich M.[5], Svajda J.[6], Adamescu M.[7], Cazacu C.[7], Medina F.M.[8], Mork?n? R.[9], Razinkovas-Baziukas A.[9], Poursanidis D.[10], Tasevska O.[11], Al Malla A.[12], Stritih A.[13, 14], Rossi C.[15], Arenas-Castro S.[16], Carvalho-Santos C.[16, 17], Smit I.P.J.[18, 19], Valentini E.[20, 21], Xuan A.N.[21], Orenstein D.[22], Provenzale A.[23], de Wit R.[3], Hummel C.[1, MARine Biodiversity Exploitation and Conservation (UMR MARBEC), and Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)
Subjects: [SDV]Life Sciences [q-bio], Essential variables, Ecosystem services, Protected areas, Ecosystem functions, Threats, Bottom-up procedure, Stakeholders, Management, Monitoring, Policy and Law, Environmental Science (miscellaneous), Agricultural and Biological Sciences (miscellaneous), [SHS]Humanities and Social Sciences, essential variables, ecosystem services, protected areas, ecosystem functions, threats, bottom-up procedure, stakeholders, Ecology, Evolution, Behavior and Systematics, ComputingMilieux_MISCELLANEOUS
Abstract: Assessing the environmental status of Protected Areas (PAs) is a challenging issue. To indicate that status, the identification of a common set of variables that are scientifically sound, and easy to assess and monitor by the PA practitioners, is particularly important. In this study, a set of 27 Essential Variables (EVs) for PA management was selected in a bottom-up process from 67 harmonised variables that describe the status of Ecosystem Functions and Structures, Ecosystem Services, and Threats in PAs. This bottom-up process involved 27 internationally recognised PAs, mostly European, with different level of protection, different extent, and a wide range of human-nature interactions. The EVs were selected by more than 120 practitioners, i.e. PA managers and rangers, as well as scientists, working in terrestrial and aquatic PAs. Across both terrestrial and aquatic PAs, scientists and practitioners largely identified the same variables as important. Data availability for these 27 EVs varied between PAs and av eraged 67% across all studied PAs. As this set of EVs for PAs is defined through a bottom-up approach considering variables already in use both in management and research, it is more than for previous EVs likely to be adopted, applied and developed to record the status and changes in the ecological and socio-economic conditions of PAs and to forecast future changes. Thereby, the EVs for PAs present a common vocabulary and tool to enhance in a uniform way the (inter)national communication, exchange and comparison of information on the status of PAs between policy makers, scientists and PA managers. The perceived status of the EVs, on an average 3.6 on a scale to a maximum of 5, indicates the surveyed PAs are in a moderate to good environmental condition. Moreover, the EVs for PAs form a cost- and time-efficient tool for PA managers to monitor developments in essential elements of their PAs, including the potential for Societal Goods and Benefits (SG&B), and to (pro-)actively tackle the potential threats that may arise in their area. Likewise, for policy makers EVs for PAs may support decision making on ecosystem management, spatial planning, and predictive modelling on the future status and requirements of PAs in their country or region., Environmental and Sustainability Indicators, 14
Published: 2022
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3. First MATISSE L -band observations of HD 179218

Author: Kokoulina, E., Matter, A., Lopez, B., Pantin, E., Ysard, N., Weigelt, G., Habart, E., Varga, J., Jones, A., Meilland, A., Dartois, E., Klarmann, L., Augereau, J.-C., Van Boekel, R., Hogerheijde, M., Yoffe, G., Waters, L., Dominik, C., Jaffe, W., Millour, F., Henning, Th., Hofmann, K.-H., Schertl, D., Lagarde, S., Petrov, R., Antonelli, P., Allouche, F., Berio, P., Robbe-Dubois, S., Ábraham, P., Beckmann, U., Bensberg, A., Bettonvil, F., Bristow, P., Cruzalèbes, P., Danchi, W., Dannhoff, M., Graser, U., Heininger, M., Labadie, L., Lehmitz, M., Leinert, C., Meisenheimer, K., Paladini, C., Percheron, I., Stee, Ph., Woillez, J., Wolf, S., Zins, G., Delbo, M., Drevon, J., Duprat, J., Gámez Rosas, V., Hocdé, V., Hron, J., Hummel, C., Isbell, J., Leftley, J., Soulain, A., Vakili, F., Wittkowski, M., Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), CEA- Saclay (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Max-Planck-Institut für Radioastronomie (MPIFR)
Subjects: [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract: International audience; Context. Carbon is one of the most abundant components in the Universe. While silicates have been the main focus of solid phase studies in protoplanetary discs (PPDs), little is known about the solid carbon content especially in the planet-forming regions (~0.1–10 au). Fortunately, several refractory carbonaceous species present C-H bonds (such as hydrogenated nano-diamond and amorphous carbon as well as polycyclic aromatic hydrocarbons), which generate infrared (IR) features that can be used to trace the solid carbon reservoirs. The new mid-IR instrument MATISSE, installed at the Very Large Telescope Interferometer (VLTI), can spatially resolve the inner regions (~1–10 au) of PPDs and locate, down to the au-scale, the emission coming from carbon grains. Aims. Our aim is to provide a consistent view on the radial structure, down to the au-scale, as well as basic physical properties and the nature of the material responsible for the IR continuum emission in the inner disk region around HD 179218. Methods. We implemented a temperature-gradient model to interpret the disk IR continuum emission, based on a multiwavelength dataset comprising a broadband spectral energy distribution and VLTI H -, L -, and N -bands interferometric data obtained in low spectral resolution. Then, we added a ring-like component, representing the carbonaceous L -band features-emitting region, to assess its detectability in future higher spectral resolution observations employing mid-IR interferometry. Results. Our temperature-gradient model can consistently reproduce our dataset. We confirmed a spatially extended inner 10 au emission in H - and L -bands, with a homogeneously high temperature (~1700 K), which we associate with the presence of stochastically heated nano-grains. On the other hand, the N -band emitting region presents a ring-like geometry that starts at about 10 au with a temperature of 400 K. Moreover, the existing low resolution MATISSE data exclude the presence of aromatic carbon grains (i.e., producing the 3.3 μm feature) in close proximity tothe star (≲1 au). Future medium spectral resolution MATISSE data will confirm their presence at larger distances. Conclusions. Our best-fit model demonstrates the presence of two separated dust populations: nano-grains that dominate the near- to mid-IR emission in the inner 10 au region and larger grains that dominate the emission outward. The presence of such nano-grains in the highly irradiated inner 10 au region of HD 179218 requires a replenishment process. Considering the expected lifetime of carbon nano-grains from The Heterogeneous dust Evolution Model for Interstellar Solids (THEMIS model), the estimated disk accretion inflow of HD 179218 could significantly contribute to feed the inner 10 au region in nano-grains.Moreover, we also expect a local regeneration of those nano-grains by the photo-fragmentation of larger aggregates.
Published: 2021

4. VLTI-MATISSE chromatic aperture-synthesis imaging of η Carinae’s stellar wind across the Br α line

Author: Weigelt, G., Hofmann, K.-H., Schertl, D., Lopez, B., Petrov, R., Lagarde, S., Berio, Ph., Jaffe, W., Henning, Th., Millour, F., Meilland, A., Allouche, F., Robbe-Dubois, S., Matter, A., Cruzalèbes, Pierre, Hillier, D., Russell, C., Madura, T., Gull, T., Corcoran, M., Damineli, A., Moffat, A., Morris, P., Richardson, N., Paladini, C., Schöller, M., Mérand, A., Glindemann, A., Beckmann, U., Heininger, M., Bettonvil, F., Zins, G., Woillez, J., Bristow, P., Sanchez-Bermudez, J., Ohnaka, K., Kraus, S., Mehner, A., Wittkowski, M., Hummel, C., Stee, P., Vakili, F., Hartman, H., Navarete, F., Hamaguchi, K., Espinoza-Galeas, D., Stevens, I., Van Boekel, R., Wolf, S., Hogerheijde, M., Dominik, C., Augereau, J.-C., Pantin, E., Waters, L., Meisenheimer, K., Varga, J., Klarmann, L., Gámez Rosas, V., Burtscher, L., Leftley, J., Isbell, J., Hocdé, V., Yoffe, G., Kokoulina, E., Hron, J., Groh, J., Kreplin, A., Rivinius, Th., de Wit, W.-J., Danchi, W.-C., Domiciano De Souza, A., Drevon, J., Labadie, L., Connot, C., Nußbaum, E., Lehmitz, M., Antonelli, P., Graser, U., Leinert, C., Max-Planck-Institut für Radioastronomie (MPIFR), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Max Planck Institute for Astronomy (MPIA), Observatoire de la Côte d'Azur (OCA), and Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], [SDU]Sciences of the Universe [physics], [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract: International audience; Context. Eta Carinae is a highly eccentric, massive binary system (semimajor axis ~15.5 au) with powerful stellar winds and a phase-dependent wind-wind collision (WWC) zone. The primary star, η Car A, is a luminous blue variable (LBV); the secondary, η Car B, is a Wolf-Rayet or O star with a faster but less dense wind. Aperture-synthesis imaging allows us to study the mass loss from the enigmatic LBV η Car. Understanding LBVs is a crucial step toward improving our knowledge about massive stars and their evolution. Aims. Our aim is to study the intensity distribution and kinematics of η Car’s WWC zone. Methods. Using the VLTI-MATISSE mid-infrared interferometry instrument, we perform Br α imaging of η Car’s distorted wind. Results. We present the first VLTI-MATISSE aperture-synthesis images of η Car A’s stellar windin several spectral channels distributed across the Br α 4.052 μm line (spectral resolving power R ~ 960). Our observations were performed close to periastron passage in February 2020 (orbital phase ~ 14.0022). The reconstructed iso-velocity images show the dependence of the primary stellar wind on wavelength or line-of-sight (LOS) velocity with a spatial resolution of 6 mas (~14 au). The radius of the faintest outer wind regions is ~26 mas (~60 au). At several negative LOS velocities, the primary stellar wind is less extended to the northwest than in other directions. This asymmetry is most likely caused by the WWC. Therefore, we see both the velocity field of the undisturbed primary wind and the WWC cavity. In continuum spectral channels, the primary star wind is more compact than in line channels. A fit of the observed continuum visibilities with the visibilities of a stellar wind CMFGEN model (CMFGEN is an atmosphere code developed to model the spectra of a variety of objects) provides a full width at half maximum fit diameter of the primary stellar wind of 2.84 ± 0.06 mas (6.54 ± 0.14 au). We comparethe derived intensity distributions with the CMFGEN stellar wind model and hydrodynamic WWC models.
Published: 2021

5. First MATISSE L-band observations of HD 179218

Author: Kokoulina, E., Matter, A., Lopez, B., Pantin, E., Ysard, N., Weigelt, G., Habart, E., Varga, J., Jones, A., Meilland, A., Dartois, E., Klarmann, L., Augereau, J.-C., Van Boekel, R., Hogerheijde, M., Yoffe, G., Waters, L. B. F. M., Dominik, C., Jaffe, W., Millour, F., Henning, Th., Hofmann, K.-H., Schertl, D., Lagarde, S., Petrov, R. G., Antonelli, P., Allouche, F., Berio, P., Robbe-Dubois, S., Ábraham, P., Beckmann, U., Bensberg, A., Bettonvil, F., Bristow, P., Cruzalèbes, P., Danchi, W. C., Dannhoff, M., Graser, U., Heininger, M., Labadie, L., Lehmitz, M., Leinert, C., Meisenheimer, K., Paladini, C., Percheron, I., Stee, Ph., Woillez, J., Wolf, S., Zins, G., Delbo, M., Drevon, J., Duprat, J., Gámez Rosas, V., Hocdé, V., Hron, J., Hummel, C. A., Isbell, J. W., Leftley, J., Soulain, A., Vakili, F., Wittkowski, M., 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), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: techniques: interferometric, protoplanetary disks, infrared: general, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], circumstellar matter
Abstract: International audience; Context. Carbon is one of the most abundant components in the Universe. While silicates have been the main focus of solid phase studies in protoplanetary discs (PPDs), little is known about the solid carbon content especially in the planet-forming regions (~0.1–10 au). Fortunately, several refractory carbonaceous species present C-H bonds (such as hydrogenated nano-diamond and amorphous carbon as well as polycyclic aromatic hydrocarbons), which generate infrared (IR) features that can be used to trace the solid carbon reservoirs. The new mid-IR instrument MATISSE, installed at the Very Large Telescope Interferometer (VLTI), can spatially resolve the inner regions (~1–10 au) of PPDs and locate, down to the au-scale, the emission coming from carbon grains.Aims. Our aim is to provide a consistent view on the radial structure, down to the au-scale, as well as basic physical properties and the nature of the material responsible for the IR continuum emission in the inner disk region around HD 179218.Methods. We implemented a temperature-gradient model to interpret the disk IR continuum emission, based on a multiwavelength dataset comprising a broadband spectral energy distribution and VLTI H-, L-, and N-bands interferometric data obtained in low spectral resolution. Then, we added a ring-like component, representing the carbonaceous L-band features-emitting region, to assess its detectability in future higher spectral resolution observations employing mid-IR interferometry.Results. Our temperature-gradient model can consistently reproduce our dataset. We confirmed a spatially extended inner 10 au emission in H- and L-bands, with a homogeneously high temperature (~1700 K), which we associate with the presence of stochastically heated nano-grains. On the other hand, the N-band emitting region presents a ring-like geometry that starts at about 10 au with a temperature of 400 K. Moreover, the existing low resolution MATISSE data exclude the presence of aromatic carbon grains (i.e., producing the 3.3 μm feature) in close proximity tothe star (≲1 au). Future medium spectral resolution MATISSE data will confirm their presence at larger distances.Conclusions. Our best-fit model demonstrates the presence of two separated dust populations: nano-grains that dominate the near- to mid-IR emission in the inner 10 au region and larger grains that dominate the emission outward. The presence of such nano-grains in the highly irradiated inner 10 au region of HD 179218 requires a replenishment process. Considering the expected lifetime of carbon nano-grains from The Heterogeneous dust Evolution Model for Interstellar Solids (THEMIS model), the estimated disk accretion inflow of HD 179218 could significantly contribute to feed the inner 10 au region in nano-grains.Moreover, we also expect a local regeneration of those nano-grains by the photo-fragmentation of larger aggregates.
Published: 2021

6. TO QUANTIFY MIXING QUALITY IN A SINGLE SCREW EXTRUDER SIMULATION

Author: Mateboer, TJ, Hummel, C., van Dijk, DJ, and Buist, J.
Subjects: Distributive mixing, Shannon entropy, Single screw extruder, Numerical simulation, CFD, Polymer mixing, Spiral Maddock, Non-Newtonian fluid dynamics
Abstract: Polymer mixing with a single screw extruder is a common process in industry. The mixing quality depends (amongst others) on the screw geometry. The main objective of this study was to develop a method for quantifying distributive mixing quality of a single screw extruder with computational fluid dynamics (CFD) simulations. Tracer particles and Shannon entropy calculations were used to determine the distributive mixing quality as a function of direction, position in the extruder and scale of observation. This method performed well for making a distinction in mixing quality between different extrusion simulations.
Published: 2020

7. Hunting Exoplanets with Single-Mode Optical Interferometry

Author: Abuter, R., Accardo, M., Adler, T., Amorim, A., Anugu, N., Ávila, G., Bauböck, M., Benisty, M., Berger, J.-P., Bestenlehner, J. M., Beust, H., Blind, N., Bonnefoy, M., BONNET, H., Bourget, P., Bouvier, J., Brandner, W., Brast, R., Buron, A., Burtscher, L., Cantalloube, F., Caratti O Garatti, A., Caselli, P., Cassaing, F., Chapron, F., Charnay, B., Choquet, E., Clénet, Y., Collin, C., Coudé Du Foresto, V., Davies, R., Deen, C., Delplancke-Ströbele, F., Dembet, R., Derie, F., de Wit, W.-J., Dexter, J., De Zeeuw, T., Dougados, C., Dubus, G., Duvert, G., Ebert, M., Eckart, A., Eisenhauer, F., Esselborn, M., Eupen, F., Fédou, P., Ferreira, M. C., Finger, G., Förster Schreiber, N. M., Gao, F., García Dabó, C. E., Garcia Lopez, R., Garcia, P. J. V., Gendron, É., Genzel, R., Gerhard, O., Gil, J. P., Gillessen, S., Gonté, F., Gordo, P., Gratadour, D., Greenbaum, A., Grellmann, R., Grözinger, U., Guajardo, P., Guieu, S., Habibi, M., Haguenauer, P., Hans, O., Haubois, X., Haug, M., Haußmann, F., Henning, T., Hippler, S., Hönig, S. F., Horrobin, M., Huber, A., Hubert, Z., Hubin, N., Hummel, C. A., Jakob, G., Janssen, A., Jimenez Rosales, A., Jochum, L., Jocou, L., Kammerer, J., Karl, M., Kaufer, A., Kellner, S., Kendrew, S., Kern, L., Kervella, P., Kiekebusch, M., Kishimoto, M., Klarmann, L., Klein, R., Köhler, R., Kok, Y., Kolb, J., Koutoulaki, M., Kulas, M., Labadie, L., Lacour, S., Lagrange, A.-M., Lapeyrère, V., Laun, W., Lazareff, B., Le Bouquin, J.-B., Léna, P., Lenzen, R., Lévêque, S., Lin, C.-C., Lippa, M., Lutz, D., Magnard, Y., Maire, A.-L., Mehrgan, L., Mérand, A., Millour, F., Mollière, P., Moulin, T., Müller, A., Müller, E., Müller, F., Netzer, H., Neumann, U., Nowak, M., Oberti, S., Ott, T., Pallanca, L., Panduro, J., Pasquini, L., Paumard, T., Percheron, I., Perraut, K., Perrin, G., Peterson, B. M., Petrucci, P.-O., Pflüger, A., Pfuhl, O., Phan Duc, T., Pineda, J. E., Plewa, P. m., Popovic, D., Pott, J.-U., Prieto, A., Pueyo, L., Rabien, S., Ramírez, A., Ramos, J. R., Rau, C., Ray, T., Riquelme, M., Rodríguez-Coira, G., Rohloff, R.-R., Rouan, D., Rousset, G., Sanchez-Bermudez, J., Schartmann, M., Scheithauer, S., Schöller, M., Schuhler, N., Segura-Cox, D., Shangguan, J., Shimizu, T. T., Spyromilio, J., Sternberg, A., Stock, M. R., Straub, O., Straubmeier, C., Sturm, E., Suárez Valles, M., Tacconi, L. J., Thi, W.-F., Tristram, K. R. W., Valenzuela, J. J., Van Boekel, R., Van Dishoeck, E. F., Vermot, P., Vincent, F., Von fellenberg, S., Waisberg, I., Wang, J. J., Wank, I., Weber, J., Weigelt, G., Widmann, F., Wieprecht, E., Wiest, M., Wiezorrek, E., Wittkowski, M., Woillez, J., Wolff, B., Yang, P., Yazici, S., Ziegler, D., Zins, G., and European Southern Observatory (ESO)
Subjects: [SDU]Sciences of the Universe [physics], Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The GRAVITY instrument was primarily conceived for imaging and astrometry of the Galactic centre. However, its sensitivity and astrometric capabilities have also enabled interferometry to reach a new domain of astrophysics: exoplanetology. In March 2019, the GRAVITY collaboration published the first spectrum and astrometry of an exoplanet obtained by optical interferometry. In this article, we show how this observation is paving the way to even more exciting discoveries — finding new planets, and characterising their atmospheres., Published in The Messenger vol. 178, pp. 47-49, December 2019.
Published: 2019

8. Images at the Highest Angular Resolution with GRAVITY: The Case of η Carinae

Author: Abuter, R., Accardo, M., Adler, T., Amorim, A., Anugu, N., Ávila, G., Bauböck, M., Benisty, M., Berger, J.-P., Bestenlehner, J. M., Beust, H., Blind, N., Bonnefoy, M., BONNET, H., Bourget, P., Bouvier, J., Brandner, W., Brast, R., Buron, A., Burtscher, L., Cantalloube, F., Caratti O Garatti, A., Caselli, P., Cassaing, F., Chapron, F., Charnay, B., Choquet, E., Clénet, Y., Collin, C., Coudé Du Foresto, V., Davies, R., Deen, C., Delplancke-Ströbele, F., Dembet, R., Derie, F., de Wit, W.-J., Dexter, J., De Zeeuw, T., Dougados, C., Dubus, G., Duvert, G., Ebert, M., Eckart, A., Eisenhauer, F., Esselborn, M., Eupen, F., Fédou, P., Ferreira, M. C., Finger, G., Förster Schreiber, N. M., Gao, F., García Dabó, C. E., Garcia Lopez, R., Garcia, P. J. V., Gendron, É., Genzel, R., Gerhard, O., Gil, J. P., Gillessen, S., Gonté, F., Gordo, P., Gratadour, D., Greenbaum, A., Grellmann, R., Grözinger, U., Guajardo, P., Guieu, S., Habibi, M., Haguenauer, P., Hans, O., Haubois, X., Haug, M., Haußmann, F., Henning, T., Hippler, S., Hönig, S. F., Horrobin, M., Huber, A., Hubert, Z., Hubin, N., Hummel, C. A., Jakob, G., Janssen, A., Jimenez Rosales, A., Jochum, L., Jocou, L., Kammerer, J., Karl, M., Kaufer, A., Kellner, S., Kendrew, S., Kern, L., Kervella, P., Kiekebusch, M., Kishimoto, M., Klarmann, L., Klein, R., Köhler, R., Kok, Y., Kolb, J., Koutoulaki, M., Kulas, M., Labadie, L., Lacour, S., Lagrange, A.-M., Lapeyrère, V., Laun, W., Lazareff, B., Le Bouquin, J.-B., Léna, P., Lenzen, R., Lévêque, S., Lin, C.-C., Lippa, M., Lutz, D., Magnard, Y., Maire, A.-L., Mehrgan, L., Mérand, A., Millour, F., Mollière, P., Moulin, T., Müller, A., Müller, E., Müller, F., Netzer, H., Neumann, U., Nowak, M., Oberti, S., Ott, T., Pallanca, L., Panduro, J., Pasquini, L., Paumard, T., Percheron, I., Perraut, K., Perrin, G., Peterson, B. M., Petrucci, P.-O., Pflüger, A., Pfuhl, O., Phan Duc, T., Pineda, J. E., Plewa, P. m., Popovic, D., Pott, J.-U., Prieto, A., Pueyo, L., Rabien, S., Ramírez, A., Ramos, J. R., Rau, C., Ray, T., Riquelme, M., Rodríguez-Coira, G., Rohloff, R.-R., Rouan, D., Rousset, G., Sanchez-Bermudez, J., Schartmann, M., Scheithauer, S., Schöller, M., Schuhler, N., Segura-Cox, D., Shangguan, J., Shimizu, T. T., Spyromilio, J., Sternberg, A., Stock, M. R., Straub, O., Straubmeier, C., Sturm, E., Suárez Valles, M., Tacconi, L. J., Thi, W.-F., Tristram, K. R. W., Valenzuela, J. J., Van Boekel, R., Van Dishoeck, E. F., Vermot, P., Vincent, F., Von fellenberg, S., Waisberg, I., Wang, J. J., Wank, I., Weber, J., Weigelt, G., Widmann, F., Wieprecht, E., Wiest, M., Wiezorrek, E., Wittkowski, M., Woillez, J., Wolff, B., Yang, P., Yazici, S., Ziegler, D., Zins, G., and European Southern Observatory (ESO)
Subjects: [SDU]Sciences of the Universe [physics], Astrophysics::High Energy Astrophysical Phenomena, 0103 physical sciences, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences
Abstract: The main goal of an interferometer is to probe the physics of astronomical objects at the highest possible angular resolution. The most intuitive way of doing this is by reconstructing images from the interferometric data. GRAVITY at the Very Large Telescope Interferometer (VLTI) has proven to be a fantastic instrument in this endeavour. In this article, we describe the reconstruction of the wind-wind collision cavity of the massive binary η Car with GRAVITY across two spectral lines: HeI and Brγ., Published in The Messenger vol. 178, pp. 31-33, December 2019.
Published: 2019

9. The Future of Exoplanet Direct Detection

Author: Monnier, J., Rau, G., Baines, E., Sanchez-Bermudez, J., Elvis, M., Ragland, S., Akeson, R., van Belle, G., Norris, R., Gordon, K., Defrère, D., Ridgway, S., Le Bouquin, J., Anugu, N., Scott, N., Kane, S., Richardson, N., Regaly, Z., Zhu, Z., Chiavassa, A., Vasisht, G., Stassun, K., Dong, C., Absil, O., Lacour, S., Weigelt, G., Gies, D., Adams, F., Calvet, N., Quanz, S., Espaillat, C., Gardner, T., Greenbaum, A., Millan-Gabet, R., Packham, C., Gai, M., Kral, Q., Berger, J., Linz, H., Klarmann, L., Bae, J., Lopez Garcia, R., Alexandre, G., Baron, F., Hartmann, L., Kishimoto, M., McClure, M., Olofsson, J., Haniff, C., Line, M., Petrov, R., Smith, M., Hummel, C., ten Brummelaar, T., De Furio, M., Rinehart, S., Leisawitz, D., Danchi, W., Huber, D., Wishnow, E., Mourard, D., Pope, B., Ireland, M., Kraus, S., Setterholm, B., White, R., ITA, USA, GBR, FRA, DEU, ESP, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Computer Science::Digital Libraries, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract: International audience; Diffraction fundamentally limits our ability to image and characterize exoplanets. Interferometry offers some advantages in exoplanet detection and characterization and we explore in this white paper some of the potential scientific breakthroughs possible.
Published: 2019

10. Multiple Star Systems in the Orion Nebula

Author: Abuter, R., Accardo, M., Adler, T., Amorim, A., Anugu, N., Ávila, G., Bauböck, M., Benisty, M., Berger, J.-P., Bestenlehner, J. M., Beust, H., Blind, N., Bonnefoy, M., BONNET, H., Bourget, P., Bouvier, J., Brandner, W., Brast, R., Buron, A., Burtscher, L., Cantalloube, F., Caratti O Garatti, A., Caselli, P., Cassaing, F., Chapron, F., Charnay, B., Choquet, E., Clénet, Y., Collin, C., Coudé Du Foresto, V., Davies, R., Deen, C., Delplancke-Ströbele, F., Dembet, R., Derie, F., de Wit, W.-J., Dexter, J., De Zeeuw, T., Dougados, C., Dubus, G., Duvert, G., Ebert, M., Eckart, A., Eisenhauer, F., Esselborn, M., Eupen, F., Fédou, P., Ferreira, M. C., Finger, G., Förster Schreiber, N. M., Gao, F., García Dabó, C. E., Garcia Lopez, R., Garcia, P. J. V., Gendron, É., Genzel, R., Gerhard, O., Gil, J. P., Gillessen, S., Gonté, F., Gordo, P., Gratadour, D., Greenbaum, A., Grellmann, R., Grözinger, U., Guajardo, P., Guieu, S., Habibi, M., Haguenauer, P., Hans, O., Haubois, X., Haug, M., Haußmann, F., Henning, T., Hippler, S., Hönig, S. F., Horrobin, M., Huber, A., Hubert, Z., Hubin, N., Hummel, C. A., Jakob, G., Janssen, A., Jimenez Rosales, A., Jochum, L., Jocou, L., Kammerer, J., Karl, M., Kaufer, A., Kellner, S., Kendrew, S., Kern, L., Kervella, P., Kiekebusch, M., Kishimoto, M., Klarmann, L., Klein, R., Köhler, R., Kok, Y., Kolb, J., Koutoulaki, M., Kulas, M., Labadie, L., Lacour, S., Lagrange, A.-M., Lapeyrère, V., Laun, W., Lazareff, B., Le Bouquin, J.-B., Léna, P., Lenzen, R., Lévêque, S., Lin, C.-C., Lippa, M., Lutz, D., Magnard, Y., Maire, A.-L., Mehrgan, L., Mérand, A., Millour, F., Mollière, P., Moulin, T., Müller, A., Müller, E., Müller, F., Netzer, H., Neumann, U., Nowak, M., Oberti, S., Ott, T., Pallanca, L., Panduro, J., Pasquini, L., Paumard, T., Percheron, I., Perraut, K., Perrin, G., Peterson, B. M., Petrucci, P.-O., Pflüger, A., Pfuhl, O., Phan Duc, T., Pineda, J. E., Plewa, P. m., Popovic, D., Pott, J.-U., Prieto, A., Pueyo, L., Rabien, S., Ramírez, A., Ramos, J. R., Rau, C., Ray, T., Riquelme, M., Rodríguez-Coira, G., Rohloff, R.-R., Rouan, D., Rousset, G., Sanchez-Bermudez, J., Schartmann, M., Scheithauer, S., Schöller, M., Schuhler, N., Segura-Cox, D., Shangguan, J., Shimizu, T. T., Spyromilio, J., Sternberg, A., Stock, M. R., Straub, O., Straubmeier, C., Sturm, E., Suárez Valles, M., Tacconi, L. J., Thi, W.-F., Tristram, K. R. W., Valenzuela, J. J., Van Boekel, R., Van Dishoeck, E. F., Vermot, P., Vincent, F., Von fellenberg, S., Waisberg, I., Wang, J. J., Wank, I., Weber, J., Weigelt, G., Widmann, F., Wieprecht, E., Wiest, M., Wiezorrek, E., Wittkowski, M., Woillez, J., Wolff, B., Yang, P., Yazici, S., Ziegler, D., Zins, G., and European Southern Observatory (ESO)
Subjects: [SDU]Sciences of the Universe [physics], Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: GRAVITY observations reveal that most massive stars in the Orion Trapezium cluster live in multiple systems. Our deep, milliarcsecond-resolution interferometry fills the gap at 1–100 astronomical units (au), which is not accessible to traditional imaging and spectroscopy, but is crucial to uncovering the mystery of high-mass star formation.The new observations find a significantly higher companion fraction than earlier studies of mostly OB associations. The observed distribution of mass ratios declines steeply with mass and follows a Salpeter power-law initial mass function. The observations therefore exclude stellar mergers as the dominant formation mechanism for massive stars in Orion., Published in The Messenger vol. 178, pp. 36-38, December 2019.
Published: 2019
Full Text: View/download PDF

11. Spatially Resolving the Inner Gaseous Disc of the Herbig Star 51 Oph through its CO Ro-vibration Emission

Author: Abuter, R., Accardo, M., Adler, T., Amorim, A., Anugu, N., Ávila, G., Bauböck, M., Benisty, M., Berger, J.-P., Bestenlehner, J. M., Beust, H., Blind, N., Bonnefoy, M., BONNET, H., Bourget, P., Bouvier, J., Brandner, W., Brast, R., Buron, A., Burtscher, L., Cantalloube, F., Caratti O Garatti, A., Caselli, P., Cassaing, F., Chapron, F., Charnay, B., Choquet, E., Clénet, Y., Collin, C., Coudé Du Foresto, V., Davies, R., Deen, C., Delplancke-Ströbele, F., Dembet, R., Derie, F., de Wit, W.-J., Dexter, J., De Zeeuw, T., Dougados, C., Dubus, G., Duvert, G., Ebert, M., Eckart, A., Eisenhauer, F., Esselborn, M., Eupen, F., Fédou, P., Ferreira, M. C., Finger, G., Förster Schreiber, N. M., Gao, F., García Dabó, C. E., Garcia Lopez, R., Garcia, P. J. V., Gendron, É., Genzel, R., Gerhard, O., Gil, J. P., Gillessen, S., Gonté, F., Gordo, P., Gratadour, D., Greenbaum, A., Grellmann, R., Grözinger, U., Guajardo, P., Guieu, S., Habibi, M., Haguenauer, P., Hans, O., Haubois, X., Haug, M., Haußmann, F., Henning, T., Hippler, S., Hönig, S. F., Horrobin, M., Huber, A., Hubert, Z., Hubin, N., Hummel, C. A., Jakob, G., Janssen, A., Jimenez Rosales, A., Jochum, L., Jocou, L., Kammerer, J., Karl, M., Kaufer, A., Kellner, S., Kendrew, S., Kern, L., Kervella, P., Kiekebusch, M., Kishimoto, M., Klarmann, L., Klein, R., Köhler, R., Kok, Y., Kolb, J., Koutoulaki, M., Kulas, M., Labadie, L., Lacour, S., Lagrange, A.-M., Lapeyrère, V., Laun, W., Lazareff, B., Le Bouquin, J.-B., Léna, P., Lenzen, R., Lévêque, S., Lin, C.-C., Lippa, M., Lutz, D., Magnard, Y., Maire, A.-L., Mehrgan, L., Mérand, A., Millour, F., Mollière, P., Moulin, T., Müller, A., Müller, E., Müller, F., Netzer, H., Neumann, U., Nowak, M., Oberti, S., Ott, T., Pallanca, L., Panduro, J., Pasquini, L., Paumard, T., Percheron, I., Perraut, K., Perrin, G., Peterson, B. M., Petrucci, P.-O., Pflüger, A., Pfuhl, O., Phan Duc, T., Pineda, J. E., Plewa, P. m., Popovic, D., Pott, J.-U., Prieto, A., Pueyo, L., Rabien, S., Ramírez, A., Ramos, J. R., Rau, C., Ray, T., Riquelme, M., Rodríguez-Coira, G., Rohloff, R.-R., Rouan, D., Rousset, G., Sanchez-Bermudez, J., Schartmann, M., Scheithauer, S., Schöller, M., Schuhler, N., Segura-Cox, D., Shangguan, J., Shimizu, T. T., Spyromilio, J., Sternberg, A., Stock, M. R., Straub, O., Straubmeier, C., Sturm, E., Suárez Valles, M., Tacconi, L. J., Thi, W.-F., Tristram, K. R. W., Valenzuela, J. J., Van Boekel, R., Van Dishoeck, E. F., Vermot, P., Vincent, F., Von fellenberg, S., Waisberg, I., Wang, J. J., Wank, I., Weber, J., Weigelt, G., Widmann, F., Wieprecht, E., Wiest, M., Wiezorrek, E., Wittkowski, M., Woillez, J., Wolff, B., Yang, P., Yazici, S., Ziegler, D., Zins, G., and European Southern Observatory (ESO)
Subjects: [SDU]Sciences of the Universe [physics], Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Near-infrared interferometry gives us the opportunity to spatially resolve the circumstellar environment of young stars at sub-astronomical-unit (au) scales, which a standalone telescope could not reach. In particular, the sensitivity of GRAVITY on the VLTI allows us to spatially resolve the CO overtone emission at 2.3 microns. In this article, we present a new method of using the model of the CO spectrum to reconstruct the differential phase signal and extract the geometry and size of the emitting region., Published in The Messenger vol. 178, pp. 40-42, December 2019.
Published: 2019
Full Text: View/download PDF

12. An Image of the Dust Sublimation Region in the Nucleus of NGC 1068

Author: Abuter, R., Accardo, M., Adler, T., Amorim, A., Anugu, N., Ávila, G., Bauböck, M., Benisty, M., Berger, J.-P., Bestenlehner, J. M., Beust, H., Blind, N., Bonnefoy, M., BONNET, H., Bourget, P., Bouvier, J., Brandner, W., Brast, R., Buron, A., Burtscher, L., Cantalloube, F., Caratti O Garatti, A., Caselli, P., Cassaing, F., Chapron, F., Charnay, B., Choquet, E., Clénet, Y., Collin, C., Coudé Du Foresto, V., Davies, R., Deen, C., Delplancke-Ströbele, F., Dembet, R., Derie, F., de Wit, W.-J., Dexter, J., De Zeeuw, T., Dougados, C., Dubus, G., Duvert, G., Ebert, M., Eckart, A., Eisenhauer, F., Esselborn, M., Eupen, F., Fédou, P., Ferreira, M. C., Finger, G., Förster Schreiber, N. M., Gao, F., García Dabó, C. E., Garcia Lopez, R., Garcia, P. J. V., Gendron, É., Genzel, R., Gerhard, O., Gil, J. P., Gillessen, S., Gonté, F., Gordo, P., Gratadour, D., Greenbaum, A., Grellmann, R., Grözinger, U., Guajardo, P., Guieu, S., Habibi, M., Haguenauer, P., Hans, O., Haubois, X., Haug, M., Haußmann, F., Henning, T., Hippler, S., Hönig, S. F., Horrobin, M., Huber, A., Hubert, Z., Hubin, N., Hummel, C. A., Jakob, G., Janssen, A., Jimenez Rosales, A., Jochum, L., Jocou, L., Kammerer, J., Karl, M., Kaufer, A., Kellner, S., Kendrew, S., Kern, L., Kervella, P., Kiekebusch, M., Kishimoto, M., Klarmann, L., Klein, R., Köhler, R., Kok, Y., Kolb, J., Koutoulaki, M., Kulas, M., Labadie, L., Lacour, S., Lagrange, A.-M., Lapeyrère, V., Laun, W., Lazareff, B., Le Bouquin, J.-B., Léna, P., Lenzen, R., Lévêque, S., Lin, C.-C., Lippa, M., Lutz, D., Magnard, Y., Maire, A.-L., Mehrgan, L., Mérand, A., Millour, F., Mollière, P., Moulin, T., Müller, A., Müller, E., Müller, F., Netzer, H., Neumann, U., Nowak, M., Oberti, S., Ott, T., Pallanca, L., Panduro, J., Pasquini, L., Paumard, T., Percheron, I., Perraut, K., Perrin, G., Peterson, B. M., Petrucci, P.-O., Pflüger, A., Pfuhl, O., Phan Duc, T., Pineda, J. E., Plewa, P. m., Popovic, D., Pott, J.-U., Prieto, A., Pueyo, L., Rabien, S., Ramírez, A., Ramos, J. R., Rau, C., Ray, T., Riquelme, M., Rodríguez-Coira, G., Rohloff, R.-R., Rouan, D., Rousset, G., Sanchez-Bermudez, J., Schartmann, M., Scheithauer, S., Schöller, M., Schuhler, N., Segura-Cox, D., Shangguan, J., Shimizu, T. T., Spyromilio, J., Sternberg, A., Stock, M. R., Straub, O., Straubmeier, C., Sturm, E., Suárez Valles, M., Tacconi, L. J., Thi, W.-F., Tristram, K. R. W., Valenzuela, J. J., Van Boekel, R., Van Dishoeck, E. F., Vermot, P., Vincent, F., Von fellenberg, S., Waisberg, I., Wang, J. J., Wank, I., Weber, J., Weigelt, G., Widmann, F., Wieprecht, E., Wiest, M., Wiezorrek, E., Wittkowski, M., Woillez, J., Wolff, B., Yang, P., Yazici, S., Ziegler, D., Zins, G., Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-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)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU]Sciences of the Universe [physics], Astrophysics::High Energy Astrophysical Phenomena, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences, Astrophysics::Galaxy Astrophysics
Abstract: The superb resolution of the Very Large Telescope Interferometer (VLTI) and the unrivalled sensitivity of GRAVITY have allowed us to reconstruct the first detailed image of the dust sublimation region in an active galaxy. In the nearby archetypal Seyfert 2 galaxy NGC 1068, the 2 µm continuum emission traces a highly inclined thin ring-like structure with a radius of 0.24 pc. The observed morphology challenges the picture of a geometrically and optically thick torus., Published in The Messenger vol. 178, pp. 24-26, December 2019.
Published: 2019

13. Probing the Discs of Herbig Ae/Be Stars at Terrestrial Orbits

Author: Abuter, R., Accardo, M., Adler, T., Amorim, A., Anugu, N., Ávila, G., Bauböck, M., Benisty, M., Berger, J.-P., Bestenlehner, J. M., Beust, H., Blind, N., Bonnefoy, M., BONNET, H., Bourget, P., Bouvier, J., Brandner, W., Brast, R., Buron, A., Burtscher, L., Cantalloube, F., Caratti O Garatti, A., Caselli, P., Cassaing, F., Chapron, F., Charnay, B., Choquet, E., Clénet, Y., Collin, C., Coudé Du Foresto, V., Davies, R., Deen, C., Delplancke-Ströbele, F., Dembet, R., Derie, F., de Wit, W.-J., Dexter, J., De Zeeuw, T., Dougados, C., Dubus, G., Duvert, G., Ebert, M., Eckart, A., Eisenhauer, F., Esselborn, M., Eupen, F., Fédou, P., Ferreira, M. C., Finger, G., Förster Schreiber, N. M., Gao, F., García Dabó, C. E., Garcia Lopez, R., Garcia, P. J. V., Gendron, É., Genzel, R., Gerhard, O., Gil, J. P., Gillessen, S., Gonté, F., Gordo, P., Gratadour, D., Greenbaum, A., Grellmann, R., Grözinger, U., Guajardo, P., Guieu, S., Habibi, M., Haguenauer, P., Hans, O., Haubois, X., Haug, M., Haußmann, F., Henning, T., Hippler, S., Hönig, S. F., Horrobin, M., Huber, A., Hubert, Z., Hubin, N., Hummel, C. A., Jakob, G., Janssen, A., Jimenez Rosales, A., Jochum, L., Jocou, L., Kammerer, J., Karl, M., Kaufer, A., Kellner, S., Kendrew, S., Kern, L., Kervella, P., Kiekebusch, M., Kishimoto, M., Klarmann, L., Klein, R., Köhler, R., Kok, Y., Kolb, J., Koutoulaki, M., Kulas, M., Labadie, L., Lacour, S., Lagrange, A.-M., Lapeyrère, V., Laun, W., Lazareff, B., Le Bouquin, J.-B., Léna, P., Lenzen, R., Lévêque, S., Lin, C.-C., Lippa, M., Lutz, D., Magnard, Y., Maire, A.-L., Mehrgan, L., Mérand, A., Millour, F., Mollière, P., Moulin, T., Müller, A., Müller, E., Müller, F., Netzer, H., Neumann, U., Nowak, M., Oberti, S., Ott, T., Pallanca, L., Panduro, J., Pasquini, L., Paumard, T., Percheron, I., Perraut, K., Perrin, G., Peterson, B. M., Petrucci, P.-O., Pflüger, A., Pfuhl, O., Phan Duc, T., Pineda, J. E., Plewa, P. m., Popovic, D., Pott, J.-U., Prieto, A., Pueyo, L., Rabien, S., Ramírez, A., Ramos, J. R., Rau, C., Ray, T., Riquelme, M., Rodríguez-Coira, G., Rohloff, R.-R., Rouan, D., Rousset, G., Sanchez-Bermudez, J., Schartmann, M., Scheithauer, S., Schöller, M., Schuhler, N., Segura-Cox, D., Shangguan, J., Shimizu, T. T., Spyromilio, J., Sternberg, A., Stock, M. R., Straub, O., Straubmeier, C., Sturm, E., Suárez Valles, M., Tacconi, L. J., Thi, W.-F., Tristram, K. R. W., Valenzuela, J. J., Van Boekel, R., Van Dishoeck, E. F., Vermot, P., Vincent, F., Von fellenberg, S., Waisberg, I., Wang, J. J., Wank, I., Weber, J., Weigelt, G., Widmann, F., Wieprecht, E., Wiest, M., Wiezorrek, E., Wittkowski, M., Woillez, J., Wolff, B., Yang, P., Yazici, S., Ziegler, D., Zins, G., and European Southern Observatory (ESO)
Subjects: [SDU]Sciences of the Universe [physics], Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: More than 4000 exoplanets are known to date in systems that differ greatly from our Solar System. In particular, inner exoplanets tend to follow orbits around their parent star that are much more compact than that of Earth. These systems are also extremely diverse, covering a range of intrinsic properties. Studying the main physi- cal processes at play in the innermost regions of the protoplanetary discs is crucial to understanding how these planets form and migrate so close to their host. With GRAVITY, we focused on the study of near-infrared emission of a sample of young intermediate- mass stars, the Herbig Ae/Be stars., Published in The Messenger vol. 178, pp. 38-40, December 2019.
Published: 2019
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14. Analysis of coastal areas using SAR images: A case study of the Dutch Wadden Sea region

Author: Dumitru, C.O., Schwartz, G., Espinoza-Molina, D., Datcu, M., Hummel, H., and Hummel, C.
Abstract: The increased availability of civil synthetic aperture radar (SAR) satellite images withdifferent resolution allows us to compare the imaging capabilities of these instruments, toassess the quality of the available data and to investigate different areas (e.g., the Wadden Sea region). In our investigation, we propose to explore the content of Terra SAR-X and Sentinel-1A satellite images via a data mining approach in which the main steps are patch tiling, feature extraction, classification, semantic annotation and visual-statistical analytics. Once all the extracted categories are mapped and quantified, then the next step is to interpret them from an environmental point of view. The objective of our study is the application of semi-automated SAR image interpretation. Its novelty is the automated multiclass categorisation of coastal areas. We found out that the north-west of the Netherlands can be interpreted routinely as land surfaces by our satellite image analyses,while for the Wadden Sea, we can discriminate the different water levels and their impact on the visibility of the tidal flats. This necessitates a selection of time series data spanning a full tidal cycle.
Published: 2018

15. GRAVITY chromatic imaging of Eta Car's core

Author: GRAVITY Collaboration, Sanchez-Bermudez, J., Weigelt, G., Bestenlehner, J. M., Kervella, P., Brandner, W., Henning, Th., Müller, A., Perrin, G., Pott, J. -U., Schöller, M., van Boekel, R., Abuter, R., Accardo, M., Amorim, A., Anugu, N., Ávila, G., Benisty, M., Berger, J. P., Blind, N., Bonnet, H., Bourget, P., Brast, R., Buron, A., Cantalloube, F., Garatti, A. Caratti o, Cassaing, F., Chapron, F., Choquet, E., Clénet, Y., Collin, C., Foresto, V. Coudé du, de Wit, W., de Zeeuw, T., Deen, C., Delplancke-Ströbele, F., Dembet, R., Derie, F., Dexter, J., Duvert, G., Ebert, M., Eckart, A., Eisenhauer, F., Esselborn, M., Fédou, P., Garcia, P. J. V., Dabo, C. E. Garcia, Lopez, R. Garcia, Gao, F., Gendron, E., Genzel, R., Gillessen, S., Haubois, X., Haug, M., Haussmann, F., Hippler, S., Horrobin, M., Huber, A., Hubert, Z., Hubin, N., Hummel, C. A., Jakob, G., Jochum, L., Jocou, L., Karl, M., Kaufer, A., Kellner, S., Kendrew, S., Kern, L., Kiekebusch, M., Klein, R., Kolb, J., Kulas, M., Lacour, S., Lapeyrère, V., Lazareff, B., Bouquin, J. -B. Le, Léna, P., Lenzen, R., Levêque, S., Lippa, M., Magnard, Y., Mehrgan, L., Mellein, M., Mérand, A., Moreno-Ventas, J., Moulin, T., Müller, E., Müller, F., Neumann, U., Oberti, S., Ott, T., Pallanca, L., Panduro, J., Pasquini, L., Paumard, T., Percheron, I., Perraut, K., Petrucci, P. -O., Pflüger, A., Pfuhl, O., Duc, T. P., Plewa, P. M., Popovic, D., Rabien, S., Ramirez, A., Ramos, J., Rau, C., Riquelme, M., Rodríguez-Coira, G., Rohloff, R. -R., Rosales, A., Rousset, G., Scheithauer, S., Schuhler, N., Spyromilio, J., Straub, O., Straubmeier, C., Sturm, E., Suarez, M., Tristram, K. R. W., Ventura, N., Vincent, F., Waisberg, I., Wank, I., Widmann, F., Wieprecht, E., Wiest, M., Wiezorrek, E., Wittkowski, M., Woillez, J., Wolff, B., Yazici, S., Ziegler, D., Zins, G., European Southern Observatory (ESO), Max-Planck-Institut für Radioastronomie (MPIFR), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Institut de biologie et chimie des protéines [Lyon] (IBCP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), CENTRA-SIM, IDL-Faculdade de Ciencias da Universidade de Lisboa, 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), Max Planck Institute for Astronomy (MPIA), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Caltech Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), Max Planck Institute for Extraterrestrial Physics (MPE), Observatoire de Paris - Site de Paris (OP), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Norwegian Institute for Air Research (NILU), European Southern Observatory [Santiago] (ESO), Department of General, Centre de recherche sur l'eau, Veolia Environnement, University of Bologna [Italy], School of Electrical Engineering (ETF), University of Belgrade [Belgrade], Universidad Mayor, Diamond Light Source, Harwell, Berks, England, Délégation à la Recherche Clinique et à l'Innovation (DRCI), Universität zu Köln, Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Technologie de Belfort-Montbeliard (UTBM), AUTRES, 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), 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]), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Astrophysics - Solar and Stellar Astrophysics, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Eta Car is one of the most intriguing luminous blue variables in the Galaxy. Observations and models at different wavelengths suggest a central binary with a 5.54 yr period residing in its core. 2D and 3D radiative transfer and hydrodynamic simulations predict a primary with a dense and slow stellar wind that interacts with the faster and lower density wind of the secondary. The wind-wind collision scenario suggests that the secondary's wind penetrates the primary's wind creating a low-density cavity in it, with dense walls where the two winds interact. We aim to trace the inner ~5-50 au structure of Eta Car's wind-wind interaction, as seen through BrG and, for the first time, through the He I 2s-2p line. We have used spectro-interferometric observations with GRAVITY at the VLTI. Our modeling of the continuum allows us to estimate its FWHM angular size close to 2 mas and an elongation ratio of 1.06 +/- 0.05 over a PA = 130 +/- 20 deg. Our CMFGEN modeling helped us to confirm that the role of the secondary should be taken into account to properly reproduce the observed BrG and He I lines. Chromatic images across BrG reveal a southeast arc-like feature, possibly associated to the hot post-shocked winds flowing along the cavity wall. The images of He I 2s-2p served to constrain the 20 mas structure of the line-emitting region. The observed morphology of He I suggests that the secondary is responsible for the ionized material that produces the line profile. Both the BrG and the He I 2s-2p maps are consistent with previous hydrodynamical models of the colliding wind scenario. Future dedicated simulations together with an extensive interferometric campaign are necessary to refine our constraints on the wind and stellar parameters of the binary, which finally will help us predict the evolutionary path of Eta Car., Comment: 32 pages, 27 figures (14 in the main body, 13 in the appendices), accepted for publication in AA
Published: 2018
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16. GRAVITY chromatic imaging of η Car's core. Milliarcsecond resolution imaging of the wind-wind collision zone (Brγ, He I)

Author: Collaboration, G., Sanchez-Bermudez, J., Weigelt, G., Bestenlehner, J., Kervella, P., Brandner, W., Henning, T., Müller, A., Perrin, G., Pott, J., Schöller, M., van Boekel, R., Abuter, R., Accardo, M., Amorim, A., Anugu, N., Ávila, G., Benisty, M., Berger, J., Blind, N., Bonnet, H., Bourget, P., Brast, R., Buron, A., Cantalloube, F., Caratti O Garatti, A., Cassaing, F., Chapron, F., Choquet, E., Clénet, Y., Collin, C., Coudé Du Foresto, V., de Wit, W., de Zeeuw, T., Deen, C., Delplancke-Ströbele, F., Dembet, R., Derie, F., Dexter, J., Duvert, G., Ebert, M., Eckart, A., Eisenhauer, F., Esselborn, M., Fédou, P., Garcia, P., Garcia Dabo, C., Garcia Lopez, R., Gao, F., Gendron, E., Genzel, R., Gillessen, S., Haubois, X., Haug, M., Haussmann, F., Hippler, S., Horrobin, M., Huber, A., Hubert, Z., Hubin, N., Hummel, C., Jakob, G., Jochum, L., Jocou, L., Karl, M., Kaufer, A., Kellner, S., Kendrew, S., Kern, L., Kiekebusch, M., Klein, R., Kolb, J., Kulas, M., Lacour, S., Lapeyrère, V., Lazareff, B., Le Bouquin, J., Léna, P., Lenzen, R., Lévêque, S., Lippa, M., Magnard, Y., Mehrgan, L., Mellein, M., Mérand, A., Moreno-Ventas, J., Moulin, T., Müller, E., Müller, F., Neumann, U., Oberti, S., Ott, T., Pallanca, L., Panduro, J., Pasquini, L., Paumard, T., Percheron, I., Perraut, K., Petrucci, P., Pflüger, A., Pfuhl, O., Duc, T., Plewa, P., Popovic, D., Rabien, S., Ramirez, A., Ramos, J., Rau, C., Riquelme, M., Rodríguez-Coira, G., Rohloff, R., Rosales, A., Rousset, G., Scheithauer, S., Schuhler, N., Spyromilio, J., Straub, O., Straubmeier, C., Sturm, E., Suarez, M., Tristram, K., Ventura, N., Vincent, F., Waisberg, I., Wank, I., Widmann, F., Wieprecht, E., Wiest, M., Wiezorrek, E., Wittkowski, M., Woillez, J., Wolff, B., Yazici, S., Ziegler, D., and Zins, G.
Subjects: Astrophysics::Solar and Stellar Astrophysics
Abstract: Context. η Car is one of the most intriguing luminous blue variables in the Galaxy. Observations and models of the X-ray, ultraviolet, optical, and infrared emission suggest a central binary in a highly eccentric orbit with a 5.54 yr period residing in its core. 2D and 3D radiative transfer and hydrodynamic simulations predict a primary with a dense and slow stellar wind that interacts with the faster and lower density wind of the secondary. The wind-wind collision scenario suggests that the secondary's wind penetrates the primary's wind creating a low-density cavity in it, with dense walls where the two winds interact. However, the morphology of the cavity and its physical properties are not yet fully constrained. Aims: We aim to trace the inner ̃5-50 au structure of η Car's wind-wind interaction, as seen through Brγ and, for the first time, through the He I 2s-2p line. Methods: We have used spectro-interferometric observations with the K-band beam-combiner GRAVITY at the VLTI. The analyses of the data include (i) parametrical model-fitting to the interferometric observables, (ii) a CMFGEN model of the source's spectrum, and (iii) interferometric image reconstruction. Results: Our geometrical modeling of the continuum data allows us to estimate its FWHM angular size close to 2 mas and an elongation ratio ∊ = 1.06 ± 0.05 over a PA = 130° ± 20°. Our CMFGEN modeling of the spectrum helped us to confirm that the role of the secondary should be taken into account to properly reproduce the observed Brγ and He I lines. Chromatic images across the Brγ line reveal a southeast arc-like feature, possibly associated to the hot post-shocked winds flowing along the cavity wall. The images of the He I 2s-2p line served to constrain the 20 mas (̃50 au) structure of the line-emitting region. The observed morphology of He I suggests that the secondary is responsible for the ionized material that produces the line profile. Both the Brγ and the He I 2s-2p maps are consistent with previous hydrodynamical models of the colliding wind scenario. Future dedicated simulations together with an extensive interferometric campaign are necessary to refine our constraints on the wind and stellar parameters of the binary, which finally will help us predict the evolutionary path of η Car.
Published: 2018

17. Stability of FORS2 Sky Flats

Author: Boffin, Henri M. J., Dobrzycka, D., Hummel, C., Moehler, S., Smoker, J., Anderson, J., and Dias, B.
Abstract: "The FORS2 calibration plan previously had a validity for imaging sky flatfields of four days. This placed some stress on the observers, especially during periods of bad weather. We therefore decided to analyse a series of flats to check if it was possible to extend this validity range, and if yes, to what level. The analysis allowed us to change the FORS2 calibration plan, increasing the validity of sky flats from four to 14 days."
Published: 2017
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18. VLTI-AMBER velocity-resolved aperture-synthesis imaging of η Carinae with a spectral resolution of 12 000

Author: Weigelt, G., Hofmann, K.-H., Schertl, D., Clementel, N., Corcoran, M. F., Damineli, A., de Wit, W.-J., Grellmann, R., Groh, J., Guieu, S., Gull, T., Heininger, M., Hillier, D. J., Hummel, C. A., Kraus, S., Madura, T., Mehner, A., Mérand, A., Millour, F., Moffat, A. F. J., Ohnaka, K., Patru, F., Petrov, R. G., Rengaswamy, S., Richardson, N. D., Rivinius, T., Schöller, M., Teodoro, M., and Wittkowski, M.
Published: 2016
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19. Scenario for the organisation of conferences and symposia. 4th edition

Author: Hummel, H. and Hummel, C.
Published: 2016

20. Making FORS2 fit for exoplanet observations (again)

Author: Boffin, H., Blanchard, G., Gonzalez, O., Moehler, S., Sedaghati, E., Gibson, N., Mario van den Ancker, Smoker, J., Anderson, J., Hummel, C., Dobrzycka, D., Smette, A., and Rupprecht, G.
Subjects: Physics - Instrumentation and Detectors, Astrophysics - Solar and Stellar Astrophysics, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: For about three years, it was known that precision spectrophotometry with FORS2 suffered from systematic errors that made quantitative observations of planetary transits impossible. We identified the Longitudinal Atmospheric Dispersion Compensator (LADC) as the most likely culprit, and therefore engaged in a project to exchange the LADC prisms with the uncoated ones from FORS1. This led to a significant improvement in the depth of FORS2 zero points, a reduction in the systematic noise, and should make FORS2 again competitive for transmission spectroscopy of exoplanets., Comment: To appear in the March issue of the ESO Messenger
Published: 2015
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21. Experience using a rapid assay for aneuploidy and microdeletion/microduplication detection in over 2,900 prenatal specimens

Author: Scott G. Sulpizio, Roger A. Schultz, Morton Sa, Jay W. Ellison, McDaniel Ld, Hummel C, Allan J. Fisher, Jill A. Rosenfeld, Beth S. Torchia, and Ravnan Jb
Subjects: Adult, Male, Embryology, medicine.medical_specialty, Microarray, Aneuploidy, Pregnancy, Prenatal Diagnosis, Chromosome Duplication, False positive paradox, medicine, Humans, Radiology, Nuclear Medicine and imaging, Retrospective Studies, Fetus, business.industry, Obstetrics, Microarray analysis techniques, Ultrasound, Obstetrics and Gynecology, Chromosome, Karyotype, General Medicine, medicine.disease, Molecular biology, Molecular Diagnostic Techniques, Pediatrics, Perinatology and Child Health, Cytogenetic Analysis, Female, business
Abstract: Background: While microarray testing can identify chromosomal abnormalities missed by karyotyping, its prenatal use is often avoided in low-risk pregnancies due to the possible identification of variants of uncertain significance (VOUS). Methods: We tested 2,970 prenatal samples of all referral indications using a rapid BACs-on-Beads-based assay with probes for sex chromosomes, common autosomal aneuploidies, and 20 microdeletion/microduplication syndromes, designed as an alternative to microarray in low-risk pregnancies and an alternative to rapid aneuploidy testing in pregnancies also undergoing microarray analysis. Results: Interpretable results were obtained in 2,940 cases (99.0%), with 89% receiving results in 1 day. Aneuploidies were detected in 7.3% and partial chromosome abnormalities in 0.45% (n = 13), including 5 referred for maternal age, abnormal maternal serum screen, or isolated ultrasound markers. The added detection above karyotype was 1 in 745 in lower-risk cases with normal ultrasounds or isolated ultrasound markers/increased nuchal measurements and 1 in 165 for fetuses with structural/growth abnormalities. Neither false negatives nor false positives were found within test limitations. Female polyploidy could not be detected, while polyploidies with Y chromosomes were suspected and confirmed through additional analysis. Conclusion: When combined with karyotyping, this assay provides increased interrogation of specific chromosomal regions, while limiting VOUS identification.
Published: 2013

22. An interferometric study of the post-AGB binary 89 Herculis

Author: Hillen, M., Verhoelst, T., Van Winckel, H., Chesneau, O., Hummel, C., Monnier, J., Farrington, C., Tycner, C., Mourard, D., Ten Brummelaar, T., Banerjee, D., Zavala, R., Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2013

23. Perception of a blending odor mixture: an fMRI study in humans

Author: Sinding , Charlotte, Coureaud , Gérard, Béno , Noëlle, Le Berre , Elodie, Hummel , C., Prescott , John, Bensafi , Moustafa, Hummel , Thomas, Thomas-Danguin , Thierry, Centre des Sciences du Goût et de l'Alimentation [Dijon] (CSGA), Centre National de la Recherche Scientifique (CNRS)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB), Julien, Sabine, Centre National de la Recherche Scientifique (CNRS), Centre des Sciences du Goût et de l'Alimentation [Dijon] ( CSGA ), Institut National de la Recherche Agronomique ( INRA ) -Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique ( CNRS ), Centre National de la Recherche Scientifique ( CNRS ), Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique (CNRS), and ProdInra, Archive Ouverte
Subjects: [SDV.AEN] Life Sciences [q-bio]/Food and Nutrition, stomatognathic diseases, InformationSystems_MODELSANDPRINCIPLES, ComputingMilieux_THECOMPUTINGPROFESSION, GeneralLiterature_INTRODUCTORYANDSURVEY, [ SDV.AEN ] Life Sciences [q-bio]/Food and Nutrition, health care facilities, manpower, and services, education, ComputingMilieux_COMPUTERSANDEDUCATION, [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition, ComputingMilieux_MISCELLANEOUS, health care economics and organizations
Abstract: Supported by grants from the Burgundy Regional council and EU-ERDF, European Dijon-Dresden Laboratory (LEA 549); Odors we perceive from our environment arise from the processing of mixtures of odorants. Some mixtures can lead to configural or elemental perception depending, in part, on experience. However, the neural bases of such influences are still unknown. In the present study, we examined the neurophysiological correlates of the configural and elemental processing of a binary odor mixture (AB). This AB mixture has previously been shown to blend into one percept, but also to produce a more or less configural perception depending on pre-exposure to either the mixture itself or to the single components of the mixture. Therefore, subjects were pre-exposed twice either to AB (group Gmix, n=12) or to its single components (A & B; Gcomp, n=14) in order to favor configural processing in the Gmix group or analytical processing in the Gcomp group. During fMRI, subjects were stimulated with AB, A and B, following a block design, using a computer-controlled olfactometer. At the end of the session, subjects rated intensity, pleasantness, and complexity for each stimulus. Psychophysical data revealed no significant difference in pleasantness but a small difference in intensity (B slightly less intense). Concerning complexity, Gmix subjects perceived the mixture as simple as the components whereas Gcomp subjects perceived the mixture as more complex, revealing experience-induced analytical processing of the mixture for this group. For fMRI data recorded when AB was the stimulus, the contrast Gcomp minus Gmix did not yield any significant differences in activation. However, the contrast Gmix minus Gcomp indicated an increased activation in five brain regions, among which the right superior frontal gyrus, already found to be specifically activated in a PET study on mixtures, and the hippocampus known to be involved in holistic processing of complex visual scenes. These preliminary results shed some light on cerebral mechanisms implied in the processing of complex odors.
Published: 2012

24. Convex hulls in singular spaces of negative curvature

Author: Hummel, C, Lang, U, Schroeder, Viktor, University of Zurich, and Hummel, C
Subjects: Alexandrov space, 10123 Institute of Mathematics, 510 Mathematics, 3320 Political Science and International Relations, 2603 Analysis, negative curvature, 2608 Geometry and Topology, almost convex, convex hull
Published: 2000

25. Carnets de bord en sciences humaines : genèse, dynamique et fin d'une revue

Author: Benninghoff, M., Cicchini, M., Ferreira, C., Frauenfelder, A., Hummel, C., Schubert, Y., and Verdrager, P.
Abstract: Ce dernier numéro est l'occasion de faire un bilan et d'analyser les raisons qui nous ont conduits à décider de mettre un terme à l'existence d'une revue que nous avons animée pendant près de dix ans. Fidèles à la ligne éditoriale, nous dévoilons les coulisses de la production de Carnets de bord. Chemin faisant, nous nous livrons à un exercice d'auto-analyse susceptible d'éclairer la fragilité de ce genre d'initiatives intellectuelles dans un contexte universitaire où les critères managériaux d'évaluation ont largement gagné du terrain.
Published: 2011

26. Tolerance to natural environmental change and the effect of added chemical stress

Author: Hummel, H., Sokolowski, A., Hummel, C., Wijnhoven, S., Amiard-Triquet, C., Rainbow, P., and Monitoring Taskforce
Abstract: no abstract
Published: 2011

27. Masses of the astrometric SB2 ��Ori A

Author: Rivinius, Th., Hummel, C. A., and Stahl, O.
Subjects: Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: We report the first dynamic mass for an O-type supergiant, the interferometrically resolved SB2 system ��Ori A (O9.5Ib+B0/1). The separation of the system excludes any previous mass-transfer, ensuring that the derived masses can be compared to single star evolutionary tracks., 2 pages, 1 figure, IAUS 272 - Active OB Stars: Structure, Evolution, Mass Loss and Critical Limits
Published: 2010
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28. Cyclic Variability of the Circumstellar Disc of the Be Star $��$ Tau. II. Testing the 2D Global Disc Oscillation Model

Author: Carciofi, A. C., Okazaki, A. T., Bouquin, J-B. le, ��tefl, S., Rivinius, Th., Baade, D., Bjorkman, J. E., and Hummel, C. A.
Subjects: Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Aims. In this paper we model, in a self-consistent way, polarimetric, photometric, spectrophotometric and interferometric observations of the classical Be star $��$ Tauri. Our primary goal is to conduct a critical quantitative test of the global oscillation scenario. Methods. We have carried out detailed three-dimensional, NLTE radiative transfer calculations using the radiative transfer code HDUST. For the input for the code we have used the most up-to-date research on Be stars to include a physically realistic description for the central star and the circumstellar disc. We adopt a rotationally deformed, gravity darkened central star, surrounded by a disc whose unperturbed state is given by a steady-state viscous decretion disc model. We further assume that disc is in vertical hydrostatic equilibrium. Results. By adopting a viscous decretion disc model for $��$ Tauri and a rigorous solution of the radiative transfer, we have obtained a very good fit of the time-average properties of the disc. This provides strong theoretical evidence that the viscous decretion disc model is the mechanism responsible for disc formation. With the global oscillation model we have successfully fitted spatially resolved VLTI/AMBER observations and the temporal V/R variations of the H$��$ and Br$��$ lines. This result convincingly demonstrates that the oscillation pattern in the disc is a one-armed spiral. Possible model shortcomings, as well as suggestions for future improvements, are also discussed., 14 pages, 9 figures, accepted to A&A
Published: 2009
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29. Einfluss eines Riechverlustes auf die Ernährung

Author: Hummel, T, Seo, HS, Teszmer, K, Krone, F, Hummel, C, Ishimaru, T, and Aschenbrenner, K
Subjects: ddc: 610
Published: 2008

30. Tests of stellar model atmospheres by optical interferometry III: NPOI and VINCI interferometry of the M0 giant gamma Sge covering 0.5 - 2.2 microns

Author: Wittkowski, M., Hummel, C. A., Aufdenberg, J. P., and Roccatagliata, V.
Subjects: Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics
Abstract: Aims: We present a comparison of the visual and NIR intensity profile of the M0 giant gamma Sagittae to plane-parallel ATLAS 9 as well as to plane-parallel & spherical PHOENIX model atmospheres. Methods: We use previously described visual interferometric data obtained with the NPOI in July 2000. We apply the recently developed technique of coherent integration, and thereby obtain visibility data of more spectral channels and with higher precision than before. In addition, we employ new measurements of the K-band diameter of gamma Sagittae obtained with the instrument VINCI at the VLTI in 2002. Results: The spherical PHOENIX model leads to a precise definition of the Rosseland angular diameter and a consistent high-precision diameter value for our NPOI and VLTI/VINCI data sets of Theta_Ross=6.06 pm 0.02 mas, with the Hipparcos parallax corresponding to R_Ross=55 pm 4 R_sun, and with the bolometric flux corresponding to an effective temperature T_eff=3805 pm 55 K. Our visual visibility data close to the first minimum and in the second lobe constrain the limb-darkening effect and are generally consistent with the model atmosphere predictions. The visual closure phases exhibit a smooth transition between 0 and pi. Conclusions: The agreement between the NPOI and VINCI diameter values increases the confidence in the model atmosphere predictions from optical to NIR wavelengths as well as in the calibration and accuracy of both interferometric facilities. The consistent night-by-night diameter values of VINCI give additional confidence in the given uncertainties. The closure phases suggest a slight deviation from circular symmetry, which may be due to surface features, an asymmetric extended layer, or a faint unknown companion., 12 pages, 9 figures, accepted by A&A. Also available from http://www.aanda.org/articles/aa/pdf/forth/aa5853_06.pdf
Published: 2006

31. The HgMn Binary Star Phi Herculis: Detection and Properties of the Secondary and Revision of the Elemental Abundances of the Primary

Author: Zavala, R. T., Adelman, S. J., Hummel, C. A., Gulliver, A. F., Caliskan, H., Armstrong, J. T., Hutter, D. J., Johnston, K. J., and Pauls, T. A.
Subjects: Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics
Abstract: Observations of the Mercury-Manganese star Phi Herculis with the Navy Prototype Optical Interferometer (NPOI) conclusively reveal the previously unseen companion in this single-lined binary system. The NPOI data were used to predict a spectral type of A8V for the secondary star Phi Her B. This prediction was subsequently confirmed by spectroscopic observations obtained at the Dominion Astrophysical Observatory. Phi Her B is rotating at 50 +/-3 km/sec, in contrast to the 8 km/sec lines of Phi Her A. Recognizing the lines from the secondary permits one to separate them from those of the primary. The abundance analysis of Phi Her A shows an abundance pattern similar to those of other HgMn stars with Al being very underabundant and Sc, Cr, Mn, Zn, Ga, Sr, Y, Zr, Ba, Ce, and Hg being very overabundant., Comment: Accepted to ApJ, 45 pages, 11 figures
Published: 2006
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32. Tests of stellar model atmospheres by optical interferometry

Author: Wittkowski, M., Hummel, C. A., Aufdenberg, J. P., and Roccatagliata, V.
Published: 2006

33. Astrophysical Quantities of Cepheid Variables Measured with the NPOI

Author: Nordgren, Tyler E., Armstrong, J. T., Germain, M. E., Hindsley, R. B., Hajian, A. R., Sudol, J. J., and Hummel, C. A.
Subjects: Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics
Abstract: We present mean angular diameters for two cepheid variables, alpha Ursae Minoris and zeta Geminorum, determined with the Navy Prototype Optical Interferometer (NPOI). We present linear radii for these cepheids and two additional cepheids, delta Cephei and eta Aquilae, previously observed at the NPOI. We find the limb-darkened angular diameter of alpha Ursae Minoris and of zeta Geminorum to be 3.28 +/- 0.02 and 1.55 +/- 0.09 milliarcseconds respectively. Using trigonometric parallaxes, we find the linear radii of alpha Ursae Minoris, zeta Geminorum, delta Cephei and eta Aquilae to be 46 (+/- 3), 60 (+25, -14), 45 (+8, -6), and 69 (+28, -15) Solar radii respectively. We compare the pulsation periods and linear radii of this sample of cepheids, which range in period from three to 11 days, to theoretical and empirical period-radius and period-radius-mass relations found in the literature. We find that the observed diameter of alpha Ursae Minoris is in excellent agreement with the predicted diameter as determined from both surface brightness techniques and theory only if alpha Ursae Minoris is a first overtone pulsator.
Published: 2000

34. A comparison of the antinociceptive effects of imipramine, tramadol and anpirtoline

Author: Hummel, T, Hummel, C, Friedel, I, Pauli, E, and Kobal, G
Subjects: Research Article
Abstract: The pain relieving properties of imipramine (100 mg orally), tramadol (150 mg orally), and anpirtoline (60 mg orally) were compared in 16 healthy subjects in a cross-over, double-blind, randomized, and placebo-controlled study. Anpirtoline exhibits analgesia which is possibly mediated via serotoninergic pathways, whereas tramadol exerts its effects at opioid receptors. The pain-relieving effect of the tricyclic antidepressant imipramine may involve both serotoninergic and opioid mechanisms. Chemo-somatosensory event-related potentials (CSSERP) were recorded after painful stimulation of the nasal mucosa with carbon dioxide. Subjects rated the perceived intensity of the stimuli by means of a visual analogue scale. In addition, acoustically evoked responses were recorded, the spontaneous EEG was analyzed in the frequency domain, the subjects' vigilance was assessed in a tracking task, and side effects of the drugs were monitored. Anpirtoline and tramadol produced a decrease of both CSSERP amplitudes and subjective estimates of pain, the effects of the former compound being greater. In contrast, after administration of imipramine no change of CSSERP amplitudes could be detected, whereas the subjective estimate of pain intensity decreased significantly. This was accompanied by a significant decrease of arousal indicating that pain relief produced by acute administration of imipramine was primarily related to its sedation action. The analgesic properties of anpirtoline were demonstrated in man. Tramadol was characterized as a week opioid analgesic. In contrast, imipramine appeared to produce its pain-relieving effects predominantly by non-specific actions. It is hypothesized that different analgesics may change ERP sources in a drug-specific manner.
Published: 1994

35. 4 Blade med Skibsmaskintegninger : udførte af Constructions-Elev C. G. Hummel efter den af ham i Juli og Aug. 1831 foretagne Opmaaling og efter Anvisning af G. F. Ursin

Author: Hummel, C. G.
Published: 1830
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36. CalVin 3 — A New Release of the ESO Calibrator Selection Tool for the VLT Interferometer

Author: Wittkowski, M., Ballester, P., Bonneau, D., Chelli, A., Chesneau, O., Cruzalèbes, P., Duvert, G., Hummel, C., Lafrasse, S., Mella, G., Melnick, J., Antoine Mérand, Mourard, D., Percheron, I., Sacuto, S., Shabun, K., Stefl, S., and Vinther, J.

37. An Overview of the MATISSE Instrument — Science, Concept and Current Status

Author: Lopez, B., Lagarde, S., Jaffe, W., Petrov, R., Schöller, M., Antonelli, P., Beckmann, U., Berio, P., Bettonvil, F., Glindemann, A., Gonzalez, J. -C, Graser, U., Hofmann, K. -H, Millour, F., Robbe-Dubois, S., Venema, L., Wolf, S., Henning, T., Lanz, T., Weigelt, G., Agocs, T., Bailet, C., Bresson, Y., Bristow, P., Dugué, M., Heininger, M., Kroes, G., Laun, W., Lehmitz, M., Neumann, U., Augereau, J. -C, Avila, G., Behrend, J., Belle, G., Jean-Philippe Berger, Boekel, R., Bonhomme, S., Bourget, P., Brast, R., Clausse, J. -M, Connot, C., Conzelmann, R., Cruzalèbes, P., Csepany, G., Danchi, W., Delbo, M., Delplancke, F., Dominik, C., Duin, A., Elswijk, E., Fantei, Y., Finger, G., Gabasch, A., Gay, J., Girard, P., Girault, V., Gitton, P., Glazenborg, A., Gonté, F., Guitton, F., Guniat, S., Haan, M., Haguenauer, P., Hanenburg, H., Hogerheijde, M., Ter Horst, R., Hron, J., Hugues, Y., Hummel, C., Idserda, J., Ives, D., Jakob, G., Jasko, A., Jolley, P., Kiraly, S., Köhler, R., Kragt, J., Kroener, T., Kuindersma, S., Labadie, L., Leinert, C., Le Poole, R., Lizon, J. -L, Lucuix, C., Marcotto, A., Martinache, F., Martinot-Lagarde, G., Mathar, R., Matter, A., Mauclert, N., Mehrgan, L., Meilland, A., Meisenheimer, K., Meisner, J., Mellein, M., Menardi, S., Menut, J. -L, Merand, A., Morel, S., Mosoni, L., Navarro, R., Nussbaum, E., Ottogalli, S., Palsa, R., Panduro, J., Pantin, E., Parra, T., Percheron, I., Duc, T. P., Pott, J. -U, Pozna, E., Przygodda, F., Rabbia, Y., Richichi, A., Rigal, F., Roelfsema, R., Rupprecht, G., Schertl, D., Schmidt, C., Schuhler, N., Schuil, M., Spang, A., Stegmeier, J., Thiam, L., Tromp, N., Vakili, F., Vannier, M., Wagner, K., and Woillez, J.

38. Combined Spectroscopic and Interferometric (NPOI) Observations of the Be star o Cassiopeiae

Author: Koubský, P., Hummel, C., Harmanec, P., Yang, S., Božić, H., Tycner, C., Robert Zavala, Rivinius, T., and Curé, M.
Subjects: astrometry, binaries: spectroscopic, stars: emission-line, Be
Abstract: The analysis of radial velocities of the Be star o Cas from spectra taken between 1992 and 2008 at Ondrejov and Dominion Astrophysical Observatories allowed us to reconfirm the binary nature of this object, first suggested by Abt and Levy in 1978, but later refuted by several authors. The orbital parameters of this SB1 system imply a very high mass function of about one solar mass. This in turn leads to a very high mass of the secondary, possibly higher than that of the primary. In order to check for the existence of such a massive secondary, o Cas was observed with the Navy Prototype Optical Interferometer, which allowed the binary components to be spatially resolved for the first time. The interferometric observations lead to the detection of a secondary, about 3 mag fainter than the primary. The possible properties of this peculiar binary system are discussed.

39. Ecosystem services in European protected areas: Ambiguity in the views of scientists and managers?

Author: Hummel C., Provenzale A., van der Meer J., Wijnhoven S., Nolte A., Poursanidis D., Janss G., Jurek M., Andresen M., Poulin B., Kobler J., Beierkuhnlein C., Honrado J., Razinkovas A., Stritih A., Bargmann T., Ziemba A., Bonet-Garcia F., Adamescu M.C., Janssen G., and Hummel H.
Subjects: coastal/marine, Knowledge, 13. Climate action, Wetlands, Manager, Camargue, Ecosystem services, Perception, 14. Life underwater, 15. Life on land
Abstract: The perception of factors related to ecosystem services differs markedly between scientists and managers based on a survey involving several protected areas. Scientists emphasise variables of abiotic and biotic nature, whereas managers highlight socio-economic, cultural and anthropogenic variables. It is concluded that intensified and harmonised communication across disciplinary and professional boundaries will be needed to implement and improve Ecosystem Service oriented management strategies in current and future protected areas.

40. The radio jet of quasar 0153+744

Author: Hummel, C. A., T. P. Krichbaum, Witzel, A., Wüllner, K. H., Steffen, W., Alef, W., and Fey, A.

41. The 2004 Optical/IR Interferometry Imaging Beauty Contest

Author: Lawson, P. R., Cotton, W. D., Hummel, C. A., John D Monnier, Zhao, M., Young, J. S., Thorsteinsson, H., Meimon, S. C., Mugnier, L., Le Besnerais, G., Thiebaut, E., and Tuthill, P. G.

42. Ecosystem services in European protected areas: Ambiguity in the views of scientists and managers?

Author: Hummel, C., Provenzale, A., Van Der Meer, J., Wijnhoven, S., Nolte, A., Poursanidis, D., Janss, G., Jurek, M., Andresen, M., Poulin, B., Kobler, J., Beierkuhnlein, C., Honrado, J., Razinkovas, A., Stritih, A., Bargmann, T., Ziemba, A., Bonet-Garcia, F., Adamescu, M.C., Janssen, G., and Hummel, H.
Subjects: coastal/marine, Knowledge, 13. Climate action, Wetlands, Manager, Camargue, Ecosystem services, Perception, 14. Life underwater, 15. Life on land
Abstract: The perception of factors related to ecosystem services differs markedly between scientists and managers based on a survey involving several protected areas. Scientists emphasise variables of abiotic and biotic nature, whereas managers highlight socio-economic, cultural and anthropogenic variables. It is concluded that intensified and harmonised communication across disciplinary and professional boundaries will be needed to implement and improve Ecosystem Service oriented management strategies in current and future protected areas.

43. PND2 BUDGET IMPACT ANALYSIS OF FIXED DOSAGE COMBINATION (FDC) OF LEVODOPA/CARBIDOPA/ENTACAPONE IN PARKINSON DISEASE TREATMENT BY DISTRITO FEDERAL PUBLIC HEALTH CARE SYSTEM

Author: Suzuki, C, Navarro, J, and Hummel, C
Subjects: Health Policy, Public Health, Environmental and Occupational Health
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44. Cusp closing in rank one symmetric spaces

Author: Christoph Hummel, Viktor Schroeder, University of Zurich, and Hummel, C
Subjects: General Mathematics, Hyperbolic space, Mathematical analysis, Hyperbolic 3-manifold, Hyperbolic manifold, Curvature, Mathematics::Geometric Topology, Relatively hyperbolic group, 10123 Institute of Mathematics, 510 Mathematics, Mathematics::Differential Geometry, Compactification (mathematics), Sectional curvature, 2600 General Mathematics, Mathematics, Scalar curvature
Abstract: We investigate conditions under which cusps of pinched negative curvature can be closed as manifolds or orbifolds with nonpositive sectional curvature. We show that all cusps of complex hyperbolic type can be closed in this way whereas cusps of quaternionic or Cayley hyperbolic type cannot be closed. For cusps of real hyperbolic type we derive necessary and sufficient closing conditions. In this context we prove that a noncompact finite volume quotient of a rank one symmetric space can be approximated in the Gromov Hausdorff topology by closed orbifolds with nonpositive curvature if and only if it is real or complex hyperbolic. Using cusp closing methods we obtain new examples of real analytic manifolds of nonpositive sectional curvature and rank one containing flats. By the same methods we get an explicit resolution of the singularities in the Baily–Borel resp.Siu–Yau compactification of finite volume quotients of the complex hyperbolic space.
Published: 1996

45. Tits geometry of cocompact real-analytic Hadamard manifolds of dimension 4

Author: Christoph Hummel, Viktor Schroeder, University of Zurich, and Hummel, C
Subjects: higher rank subspaces, Nonpositive curvature, Dimension (graph theory), Boundary (topology), Rigidity (psychology), Geometry, Rank (differential topology), Mathematics::Group Theory, Corollary, 510 Mathematics, Hadamard transform, Mathematics::Metric Geometry, Tits geometry, Mathematics::Representation Theory, Mathematics::Symplectic Geometry, Mathematics, homogeneous spaces, 2603 Analysis, Hadamard manifold, 10123 Institute of Mathematics, Computational Theory and Mathematics, 2608 Geometry and Topology, Mathematics::Differential Geometry, Geometry and Topology, Isometry group, Analysis, 1703 Computational Theory and Mathematics
Abstract: Let X be a 4-dimensional irreducible real analytic Hadamard manifold with cocompact isometry group Iso( X ). We show that if Iso( X ) is not discrete, then the Tits boundary of X is isometric to the Tits boundary of a homogeneous Hadamard manifold. As a corollary we obtain a rank rigidity result for these manifolds.
Published: 1999

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