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1. Tetris-inspired detector with neural network for radiation mapping

Author

Ryotaro Okabe, Shangjie Xue, Jayson R. Vavrek, Jiankai Yu, Ryan Pavlovsky, Victor Negut, Brian J. Quiter, Joshua W. Cates, Tongtong Liu, Benoit Forget, Stefanie Jegelka, Gordon Kohse, Lin-wen Hu, and Mingda Li

Subjects
Science
Abstract

Abstract Radiation mapping has attracted widespread research attention and increased public concerns on environmental monitoring. Regarding materials and their configurations, radiation detectors have been developed to identify the position and strength of the radioactive sources. However, due to the complex mechanisms of radiation-matter interaction and data limitation, high-performance and low-cost radiation mapping is still challenging. Here, we present a radiation mapping framework using Tetris-inspired detector pixels. Applying inter-pixel padding for enhancing contrast between pixels and neural networks trained with Monte Carlo (MC) simulation data, a detector with as few as four pixels can achieve high-resolution directional prediction. A moving detector with Maximum a Posteriori (MAP) further achieved radiation position localization. Field testing with a simple detector has verified the capability of the MAP method for source localization. Our framework offers an avenue for high-quality radiation mapping with simple detector configurations and is anticipated to be deployed for real-world radiation detection.

Published
2024
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2. Free-moving Quantitative Gamma-ray Imaging

Author

Daniel Hellfeld, Mark S. Bandstra, Jayson R. Vavrek, Donald L. Gunter, Joseph C. Curtis, Marco Salathe, Ryan Pavlovsky, Victor Negut, Paul J. Barton, Joshua W. Cates, Brian J. Quiter, Reynold J. Cooper, Kai Vetter, and Tenzing H. Y. Joshi

Subjects
Medicine, Science
Abstract

Abstract The ability to map and estimate the activity of radiological source distributions in unknown three-dimensional environments has applications in the prevention and response to radiological accidents or threats as well as the enforcement and verification of international nuclear non-proliferation agreements. Such a capability requires well-characterized detector response functions, accurate time-dependent detector position and orientation data, a digitized representation of the surrounding 3D environment, and appropriate image reconstruction and uncertainty quantification methods. We have previously demonstrated 3D mapping of gamma-ray emitters with free-moving detector systems on a relative intensity scale using a technique called Scene Data Fusion (SDF). Here we characterize the detector response of a multi-element gamma-ray imaging system using experimentally benchmarked Monte Carlo simulations and perform 3D mapping on an absolute intensity scale. We present experimental reconstruction results from hand-carried and airborne measurements with point-like and distributed sources in known configurations, demonstrating quantitative SDF in complex 3D environments.

Published
2021
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5. Mapping the Minimum Detectable Activities of Gamma-Ray Sources in a 3-D Scene

Author

M. S. Bandstra, D. Hellfeld, J. Lee, B. J. Quiter, M. Salathe, J. R. Vavrek, and T. H. Y. Joshi

Subjects
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Nuclear Energy and Engineering, Physics - Data Analysis, Statistics and Probability, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Electrical and Electronic Engineering, Data Analysis, Statistics and Probability (physics.data-an)
Abstract

The ability to formulate maps of minimum detectable activities (MDAs) that describe the sensitivity of an ad hoc measurement that used one or more freely moving radiation detector systems would be significantly beneficial for the conduct and understanding of many radiological search activities. In a real-time scenario with a free-moving detector system, an MDA map can provide useful feedback to the operator about which areas have not been searched as thoroughly as others, thereby allowing the operator to prioritize future actions. Similarly, such a calculation could be used to inform subsequent navigation decisions of autonomous platforms. Here we describe a near real-time MDA mapping approach that can be applied when searching for point sources using detected events in a spectral region of interest while assuming a constant, unknown background rate. We show the application of this MDA mapping method to a real scenario, a survey of the interior of a small building using a handheld detector system. Repeated measurements with no sources and with Cs-137 sources of different strengths yield results consistent with the estimated thresholds and MDA values; namely, that for background-only measurements no sources are seen above threshold anywhere in the scene, while when sources are present they are detected above the thresholds calculated for their locations., 12 pages, 9 figures, submitted to IEEE Transactions on Nuclear Science

Published
2022

6. Euclid mission status

Author

Marc Sauvage, J. Hoar, Stefanie Wachter, A. Short, L. Gaspar Venancio, Warren Holmes, G. Saavedra Criado, Mark Cropper, Yannick Mellier, P. Musi, Knud Jahnke, Ulf E. Israelsson, Luca Stagnaro, R. Kohley, V. Cazaubiel, Michael Seiffert, Anne Ealet, Guillermo Buenadicha, Giuseppe D. Racca, J. Amiaux, Michel Berthé, R. Vavrek, Cyril Colombo, S. Pottinger, S. Niemi, P. Strada, Jean-Christophe Salvignol, R. J. Laureijs, Alberto Anselmi, Thierry Maciaszek, J. Lorenzo Alvarez, Fabio Pasian, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de Marseille Provence (OAMP), and Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Scientific instrument, Spacecraft, Computer science, Payload, business.industry, ComputerApplications_COMPUTERSINOTHERSYSTEMS, law.invention, Telescope, Spitzer Space Telescope, law, [SDU]Sciences of the Universe [physics], Systems engineering, Key (cryptography), business, Simulation
Abstract

International audience; In June 2012, Euclid, ESA's Cosmology mission was approved for implementation. Afterwards the industrial contracts were signed for the payload module and the spacecraft prime, and the mission requirements consolidated. We present the status of the mission in the light of the design solutions adopted by the contractors. The performances of the spacecraft in its operation, the telescope assembly, the scientific instruments as well as the data-processing have been carefully budgeted to meet the demanding scientific requirements. We give an overview of the system and where necessary the key items for the interfaces between the subsystems.

Published
2022

7. Improved Gamma-Ray Point Source Quantification in Three Dimensions by Modeling Attenuation in the Scene

Author

Daniel Hellfeld, Paul Barton, Mark S. Bandstra, Victor Negut, Joshua W. Cates, Ryan Pavlovsky, A. Moran, Tenzing H. Y. Joshi, Brian J. Quiter, Jayson R. Vavrek, and Kathryn Meehan

Subjects
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Attenuation correction, Point source, Acoustics, Biomedical Engineering, FOS: Physical sciences, maximum likelihood estimation, radiological source localization, Atomic, physics.data-an, Particle and Plasma Physics, Position (vector), Parameter estimation, Nuclear, Electrical and Electronic Engineering, Maximum likelihood detection, physics.ins-det, Physics, Estimation theory, Attenuation, Detector, Molecular, Ranging, Instrumentation and Detectors (physics.ins-det), radiological source search, Nuclear & Particles Physics, Other Physical Sciences, Laser radar, Nuclear Energy and Engineering, Attenuation coefficient, Physics - Data Analysis, Statistics and Probability, gamma-ray imaging, Ray casting, Solid modeling, Gamma-rays, Data Analysis, Statistics and Probability (physics.data-an)
Abstract

Using a series of detector measurements taken at different locations to localize a source of radiation is a well-studied problem. The source of radiation is sometimes constrained to a single point-like source, in which case the location of the point source can be found using techniques such as maximum likelihood. Recent advancements have shown the ability to locate point sources in 2D and even 3D, but few have studied the effect of intervening material on the problem. In this work we examine gamma-ray data taken from a freely moving system and develop voxelized 3-D models of the scene using data from the onboard LiDAR. Ray casting is used to compute the distance each gamma ray travels through the scene material, which is then used to calculate attenuation assuming a single attenuation coefficient for solids within the geometry. Parameter estimation using maximum likelihood is performed to simultaneously find the attenuation coefficient, source activity, and source position that best match the data. Using a simulation, we validate the ability of this method to reconstruct the true location and activity of a source, along with the true attenuation coefficient of the structure it is inside, and then we apply the method to measured data with sources and find good agreement., 10 pages, 8 figures, accepted for publication in IEEE Transactions on Nuclear Science

Published
2021

8. Free-moving Quantitative Gamma-ray Imaging

Author

Joshua W. Cates, Kai Vetter, D. Hellfeld, M. Salathe, Victor Negut, Mark S. Bandstra, Reynold J. Cooper, Brian J. Quiter, Jayson R. Vavrek, Paul Barton, Ryan Pavlovsky, Joseph C. Curtis, Tenzing H. Y. Joshi, and Donald Gunter

Subjects
Physics - Instrumentation and Detectors, Scale (ratio), Computer science, Science, Monte Carlo method, FOS: Physical sciences, Bioengineering, Iterative reconstruction, Imaging techniques, Article, Engineering, Position (vector), Computer vision, Uncertainty quantification, Multidisciplinary, Orientation (computer vision), business.industry, Prevention, Detector, Instrumentation and Detectors (physics.ins-det), Sensor fusion, Applied physics, Medicine, Artificial intelligence, business
Abstract

The ability to map and estimate the activity of radiological source distributions in unknown three-dimensional environments has applications in the prevention and response to radiological accidents or threats as well as the enforcement and verification of international nuclear non-proliferation agreements. Such a capability requires well-characterized detector response functions, accurate time-dependent detector position and orientation data, a digitized representation of the surrounding 3D environment, and appropriate image reconstruction and uncertainty quantification methods. We have previously demonstrated 3D mapping of gamma-ray emitters with free-moving detector systems on a relative intensity scale using a technique called Scene Data Fusion (SDF). Here we characterize the detector response of a multi-element gamma-ray imaging system using experimentally benchmarked Monte Carlo simulations and perform 3D mapping on an absolute intensity scale. We present experimental reconstruction results from hand-carried and airborne measurements with point-like and distributed sources in known configurations, demonstrating quantitative SDF in complex 3D environments., Comment: 20 pages, 5 figures, 4 supplementary figures, published in Scientific Reports

Published
2021
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9. Status of the performance of the Euclid spacecraft

Author

R. Vavrek, Tobias Boenke, A. Short, R. J. Laureijs, Paolo Strada, Giuseppe D. Racca, Luis M. Gaspar Venancio, Luciana Bonino, J. Amiaux, and Lionel Carminati

Subjects
Space segment, Spacecraft, Computer science, business.industry, Payload, Dark matter, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, law.invention, Telescope, Service module, law, Physics::Space Physics, Dark energy, Astrophysics::Earth and Planetary Astrophysics, Aerospace engineering, business
Abstract

The Euclid mission, of which the spacecraft is the essential space segment, is being developed to undertake the challenges of mapping the dark energy and dark matter distribution in the Universe. As the launch date is approaching (2nd half of 2022), the development of the spacecraft has successfully passed critical milestones with the manufacturing and integration of the telescope, instruments and service module. Each sub-element of the spacecraft has been qualified and their performance assessed. The assembly of the complete payload and spacecraft is currently on-going. The integrated optical performance end to end of the payload module is currently being assessed based on the as-built knowledge of the parts of the telescope and instruments.

Published
2020

10. Reconstructing the Position and Intensity of Multiple Gamma-Ray Point Sources with a Sparse Parametric Algorithm

Author

Reynold J. Cooper, Ryan Pavlovsky, Daniel Hellfeld, Joshua W. Cates, Mark S. Bandstra, Victor Negut, Kathryn Meehan, Tenzing H. Y. Joshi, Jayson R. Vavrek, Brian J. Quiter, and William Joe Vanderlip

Subjects
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, source localization, Point source, Biomedical Engineering, FOS: Physical sciences, Bioengineering, Iterative reconstruction, 01 natural sciences, Atomic, Particle and Plasma Physics, Position (vector), 0103 physical sciences, Point (geometry), Gamma-ray imaging, Nuclear, Electrical and Electronic Engineering, maximum likelihood, physics.ins-det, Parametric statistics, Mathematics, 010308 nuclear & particles physics, Detector, Gamma ray, Molecular, Maximization, Instrumentation and Detectors (physics.ins-det), radiological source search, Nuclear & Particles Physics, Poisson likelihood, Other Physical Sciences, Nuclear Energy and Engineering, Biomedical Imaging, Algorithm
Abstract

We present an experimental demonstration of Additive Point Source Localization (APSL), a sparse parametric imaging algorithm that reconstructs the 3D positions and activities of multiple gamma-ray point sources. Using a handheld gamma-ray detector array and up to four $8$ ${\mu}$Ci $^{137}$Cs gamma-ray sources, we performed both source-search and source-separation experiments in an indoor laboratory environment. In the majority of the source-search measurements, APSL reconstructed the correct number of sources with position accuracies of ${\sim}20$ cm and activity accuracies (unsigned) of ${\sim}20\%$, given measurement times of two to three minutes and distances of closest approach (to any source) of ${\sim}20$ cm. In source-separation measurements where the detector could be moved freely about the environment, APSL was able to resolve two sources separated by $75$ cm or more given only ${\sim}60$ s of measurement time. In these source-separation measurements, APSL produced larger total activity errors of ${\sim}40\%$, but obtained source separation distances accurate to within $15$ cm. We also compare our APSL results against traditional Maximum Likelihood-Expectation Maximization (ML-EM) reconstructions, and demonstrate improved image accuracy and interpretability using APSL over ML-EM. These results indicate that APSL is capable of accurately reconstructing gamma-ray source positions and activities using measurements from existing detector hardware., Comment: 10 pages, 9 figures. Accepted for publication at IEEE Transactions on Nuclear Science

Published
2020
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11. Physical cryptographic verification of nuclear warheads

Author

Jayson R. Vavrek, Ruaridh R. Macdonald, Areg Danagoulian, and R. Scott Kemp

Subjects
0301 basic medicine, Engineering, Multidisciplinary, business.industry, Poison control, Interactive proof system, Cryptography, 010403 inorganic & nuclear chemistry, Computer security, computer.software_genre, Object (computer science), 01 natural sciences, 0104 chemical sciences, 03 medical and health sciences, 030104 developmental biology, Software, Warhead, Computer engineering, Physical Sciences, Cryptographic hash function, business, Protocol (object-oriented programming), computer
Abstract

How does one prove a claim about a highly sensitive object such as a nuclear weapon without revealing information about the object? This paradox has challenged nuclear arms control for more than five decades. We present a mechanism in the form of an interactive proof system that can validate the structure and composition of an object, such as a nuclear warhead, to arbitrary precision without revealing either its structure or composition. We introduce a tomographic method that simultaneously resolves both the geometric and isotopic makeup of an object. We also introduce a method of protecting information using a provably secure cryptographic hash that does not rely on electronics or software. These techniques, when combined with a suitable protocol, constitute an interactive proof system that could reject hoax items and clear authentic warheads with excellent sensitivity in reasonably short measurement times.

Published
2016

12. Validation of Geant4's G4NRF module against nuclear resonance fluorescence data from $^{238}$U and $^{27}$Al

Author

Areg Danagoulian, Brian S. Henderson, and Jayson R. Vavrek

Subjects
Experimental validation, Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, G4NRF, Nuclear resonance fluorescence, Analytical chemistry, FOS: Physical sciences, Geant4, nucl-ex, Atomic, 01 natural sciences, Particle and Plasma Physics, 0103 physical sciences, Nuclear, Nuclear Experiment (nucl-ex), 010306 general physics, physics.ins-det, Instrumentation, Nuclear Experiment, Applied Physics, Physics, 010308 nuclear & particles physics, Molecular, Absolute level, Instrumentation and Detectors (physics.ins-det), Geochemistry, Interdisciplinary Engineering
Abstract

G4NRF is a simulation module for modeling nuclear resonance fluorescence (NRF) interactions in the Geant4 framework. In this work, we validate G4NRF against both absolute and relative measurements of three NRF interactions near 2.2 MeV in $^{238}$U and $^{27}$Al using the transmission NRF data from the experiments described in arXiv:1712.02904. Agreement between the absolute NRF count rates observed in the data and predicted by extensive Geant4+G4NRF modeling validate the combined Geant4+G4NRF to within $15$--$20\%$ in the $^{238}$U NRF transitions and $8\%$ in $^{27}$Al, for an average $13\%$ discrepancy across the entire study. The difference between simulation and experiment in relative NRF rates, as expressed as ratios of count rates in various NRF lines, is found at the level of ${\lesssim}4\%$, and is statistically identical to zero. Inverting the analysis, approximate values of the absolute level widths and branching ratios for $^{238}$U and $^{27}$Al are also obtained., 12 pages, 4 figures, 4 tables; revisions after peer review comments, chiefly making the paper more concise and the reporting of results more clear

Published
2018

14. High-accuracy Geant4 simulation and semi-analytical modeling of nuclear resonance fluorescence

Author

Jayson R. Vavrek, Brian S. Henderson, Areg Danagoulian, and Massachusetts Institute of Technology. Department of Nuclear Science and Engineering

Subjects
Nuclear and High Energy Physics, Work (thermodynamics), Photon, Physics - Instrumentation and Detectors, Applied physics, G4NRF, Monte Carlo method, Nuclear resonance fluorescence, Geant4, FOS: Physical sciences, 01 natural sciences, Atomic, Cross section (physics), Particle and Plasma Physics, 0103 physical sciences, Nuclear, 010306 general physics, Instrumentation, physics.ins-det, Applied Physics, Physics, 010308 nuclear & particles physics, Verification, Molecular, Instrumentation and Detectors (physics.ins-det), Computational physics, Numerical integration, Gaussian approximation, Benchmarking, Geochemistry, Interdisciplinary Engineering
Abstract

Nuclear resonance fluorescence (NRF) is a photonuclear interaction that enables highly isotope-specific measurements in both pure and applied physics scenarios. High-accuracy design and analysis of NRF measurements in complex geometries is aided by Monte Carlo simulations of photon physics and transport, motivating Jordan and Warren (2007) to develop the G4NRF codebase for NRF simulation in Geant4. In this work, we enhance the physics accuracy of the G4NRF code and perform improved benchmarking simulations. The NRF cross section calculation in G4NRF, previously a Gaussian approximation, has been replaced with a full numerical integration for improved accuracy in thick-target scenarios. A high-accuracy semi-analytical model of expected NRF count rates in a typical NRF measurement is then constructed and compared against G4NRF simulations for both simple homogeneous and more complex heterogeneous geometries. Agreement between rates predicted by the semi-analytical model and G4NRF simulation is found at a level of ∼1% in simple test cases and ∼3% in more realistic scenarios, improving upon the ∼20% level of the initial benchmarking study and establishing a highly-accurate NRF framework for Geant4. Keywords: Nuclear resonance fluorescence; G4NRF; Geant4; Benchmarking; Verification, United States. Department of Energy (Award DE-NA0002534)

Published
2018
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15. Experimental demonstration of an isotope-sensitive warhead verification technique using nuclear resonance fluorescence

Author

Jayson R. Vavrek, Brian S. Henderson, and Areg Danagoulian

Subjects
0301 basic medicine, Physics - Physics and Society, Multidisciplinary, Physics - Instrumentation and Detectors, 010308 nuclear & particles physics, business.industry, Computer science, Nuclear engineering, Design information, Detector, Verification problem, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Physics and Society (physics.soc-ph), Cryptographic protocol, Encryption, 01 natural sciences, Semiconductor detector, 03 medical and health sciences, 030104 developmental biology, Warhead, Physical Sciences, 0103 physical sciences, Nuclear resonance fluorescence, business
Abstract

Future nuclear arms reduction efforts will require technologies to verify that warheads slated for dismantlement are authentic without revealing any sensitive weapons design information to international inspectors. Despite several decades of research, no technology has met these requirements simultaneously. Recent work by Kemp et al. [Kemp RS, Danagoulian A, Macdonald RR, Vavrek JR (2016) Proc Natl Acad Sci USA 113:8618--8623] has produced a novel physical cryptographic verification protocol that approaches this treaty verification problem by exploiting the isotope-specific nature of nuclear resonance fluorescence (NRF) measurements to verify the authenticity of a warhead. To protect sensitive information, the NRF signal from the warhead is convolved with that of an encryption foil that contains key warhead isotopes in amounts unknown to the inspector. The convolved spectrum from a candidate warhead is statistically compared against that from an authenticated template warhead to determine whether the candidate itself is authentic. Here we report on recent proof-of-concept warhead verification experiments conducted at the Massachusetts Institute of Technology. Using high-purity germanium (HPGe) detectors, we measured NRF spectra from the interrogation of proxy 'genuine' and 'hoax' objects by a 2.52 MeV endpoint bremsstrahlung beam. The observed differences in NRF intensities near 2.2 MeV indicate that the physical cryptographic protocol can distinguish between proxy genuine and hoax objects with high confidence in realistic measurement times., Comment: 38 pages, 19 figures; revised for peer review and copy editing; addition to SI for realistic scenario projections; minor length reduction for journal requirements

Published
2017
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16. Model-based system engineering approach for the Euclid mission to manage scientific and technical complexity

Author

R. Vavrek, Harold Metselaar, Jose Lorenzo Alvarez, Luis M. Gaspar Venancio, René J. Laureijs, Jean-Christophe Salvignol, Jérôme Amiaux, and Gonzalo Saavedra Criado

Subjects
Information management, System of systems, Requirements management, Standardization, Computer science, Systems modeling, 01 natural sciences, 010309 optics, Level of Effort, Systems Modeling Language, Software deployment, 0103 physical sciences, Complexity management, Systems engineering, Added value, 010303 astronomy & astrophysics
Abstract

In the last years, the system engineering field is coming to terms with a paradigm change in the approach for complexity management. Different strategies have been proposed to cope with highly interrelated systems, system of systems and collaborative system engineering have been proposed and a significant effort is being invested into standardization and ontology definition. In particular, Model Based System Engineering (MBSE) intends to introduce methodologies for a systematic system definition, development, validation, deployment, operation and decommission, based on logical and visual relationship mapping, rather than traditional 'document based' information management. The practical implementation in real large-scale projects is not uniform across fields. In space science missions, the usage has been limited to subsystems or sample projects with modeling being performed 'a-posteriori' in many instances. The main hurdle for the introduction of MBSE practices in new projects is still the difficulty to demonstrate their added value to a project and whether their benefit is commensurate with the level of effort required to put them in place. In this paper we present the implemented Euclid system modeling activities, and an analysis of the benefits and limitations identified to support in particular requirement break-down and allocation, and verification planning at mission level.

Published
2016

17. Coating induced phase shift and impact on Euclid imaging performance

Author

Jose Lorenzo Alvarez, R. Vavrek, Jérôme Amiaux, P. Strada, Luis M. Gaspar Venancio, Lionel Carminati, Jean-Christophe Salvignol, R. J. Laureijs, Tobias Boenke, Alex Short, and Luciana Bonino

Subjects
Wavefront, Materials science, Image quality, business.industry, engineering.material, Dichroic glass, law.invention, Telescope, Wavelength, Optical coating, Optics, Coating, law, engineering, business
Abstract

The challenging constraints imposed on the Euclid telescope imaging performances have driven the design, manufacturing and characterisation of the multi-layers coatings of the dichroic. Indeed it was found that the coatings layers thickness inhomogeneity will introduce a wavelength dependent phase-shift resulting in degradation of the image quality of the telescope. Such changes must be characterized and/or simulated since they could be non-negligible contributors to the scientific performance accuracy. Several papers on this topic can be found in literature, however the results can not be applied directly to Euclid’s dichroic coatings. In particular an applicable model of the phase-shift variation with the wavelength could not be found and was developed. The results achieved with the mathematical model are compared to experimental results of tests performed on a development prototype of the Euclid’s dichroic.

Published
2016

18. The Euclid mission design

Author

Marc Sauvage, J. Hoar, Valentina Lesna, Cyril Colombo, Jérôme Amiaux, Yannick Mellier, R. Vavrek, Alex Short, Roberto Scaramella, Michel Berthé, Sylvain Prezelus, S. Pottinger, Elena Maiorano, Paolo Musi, R. Kohley, Tobias Boenke, Thierry Maciaszek, Jacques Pinel, Paolo Strada, Anne Ealet, Ruyman Azzollini, Luis Gaspar Venancio, H. Rozemeijer, Jean Christophe Salvignol, Micha Schmidt, Marco Sias, Luca Stagnaro, Fabio Pasian, Knud Jahnke, Adriano Calvi, René J. Laureijs, Pierluigi Rosato, Andrea Zacchei, Jose Lorenzo Alvarez, Vincent Cazaubiel, Mark Cropper, Giuseppe D. Racca, Osvaldo Piersanti, Andreas Rudolph, Alberto Anselmi, Gonzalo Saavedra Criado, Ludovic Vaillon, ITA, GBR, FRA, DEU, ESP, NLD, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and EUCLID

Subjects
Computer science, media_common.quotation_subject, Dark matter, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 7. Clean energy, law.invention, Photometry (optics), Telescope, Service module, law, 0103 physical sciences, Ground segment, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Weak gravitational lensing, media_common, Spacecraft, 010308 nuclear & particles physics, Payload, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Redshift, Galaxy, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 13. Climate action, Sky, Dark energy, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, business
Abstract

Euclid is a space-based optical/near-infrared survey mission of the European Space Agency (ESA) to investigate the nature of dark energy, dark matter and gravity by observing the geometry of the Universe and on the formation of structures over cosmological timescales. Euclid will use two probes of the signature of dark matter and energy: Weak gravitational Lensing, which requires the measurement of the shape and photometric redshifts of distant galaxies, and Galaxy Clustering, based on the measurement of the 3-dimensional distribution of galaxies through their spectroscopic redshifts. The mission is scheduled for launch in 2020 and is designed for 6 years of nominal survey operations. The Euclid Spacecraft is composed of a Service Module and a Payload Module. The Service Module comprises all the conventional spacecraft subsystems, the instruments warm electronics units, the sun shield and the solar arrays. In particular the Service Module provides the extremely challenging pointing accuracy required by the scientific objectives. The Payload Module consists of a 1.2 m three-mirror Korsch type telescope and of two instruments, the visible imager and the near-infrared spectro-photometer, both covering a large common field-of-view enabling to survey more than 35% of the entire sky. All sensor data are downlinked using K-band transmission and processed by a dedicated ground segment for science data processing. The Euclid data and catalogues will be made available to the public at the ESA Science Data Centre., Comment: 23 pages, 19 figures, Presented at the SPIE Astronomical Telescopes and Instrumentation conference in Edinburgh, Scotland, United Kingdom, 6 June 1 July 2016

Published
2016

19. Herschel PACS far-IR spectral imaging of a jet from an intermediate mass protostar in the OMC-2 region

Author

B. Gonzalez-Garcia, R. Vavrek, Friedrich Wyrowski, William J. Fischer, John J. Tobin, Amelia M. Stutz, M. Sanchez-Portal, Mayra Osorio, A. K. Diaz Rodriguez, T. L. Wilson, P. Manoj, S. T. Megeath, Dan M. Watson, European Commission, and Ministerio de Economía y Competitividad (España)

Subjects
Physics, Jet (fluid), medicine.medical_specialty, 010308 nuclear & particles physics, jets and outflows [ISM], Stars: formation, FOS: Physical sciences, Techniques: spectroscopic, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Spectral imaging, spectroscopic [Techniques], ISM: jets and outflows, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, medicine, Protostar, 010303 astronomy & astrophysics, formation [Stars], Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

We present the first detection of a jet in the far-IR [O I] lines from an intermediate mass protostar. This jet was detected in a Herschel/PACS spectral mapping study in the [O I] lines of OMC-2 FIR 3 and FIR 4, two of the most luminous protostars in Orion outside of the Orion Nebula. The spatial morphology of the fine structure line emission reveals the presence of an extended photodissociation region (PDR) and a narrow, but intense jet connecting the two protostars. The jet seen in [O I] emission is spatially aligned with the Spitzer/IRAC 4.5 μm jet and the CO (6-5) molecular outflow centered on FIR 3. The mass-loss rate derived from the total [O I] 63 μm line luminosity of the jet is 7.7 × 10Myr, more than an order of magnitude higher than that measured for typical low-mass class 0 protostars. The implied accretion luminosity is significantly higher than the observed bolometric luminosity of FIR 4, indicating that the [O I] jet is unlikely to be associated with FIR 4. We argue that the peak line emission seen toward FIR 4 originates in the terminal shock produced by the jet driven by FIR 3. The higher mass-loss rate that we find for FIR 3 is consistent with the idea that intermediate-mass protostars drive more powerful jets than their low-mass counterparts. Our results also call into question the nature of FIR 4. © ESO, 2016., M.O. and A.K.D.R. acknowledge support from MINECO (Spain) AYA2011-3O228-CO3-01 and AYA2014-57369-C3-3-P grants (co-funded with FEDER funds).

Published
2016

20. Filamentary structure and magnetic field orientation in Musca

Author

Pierre Royer, J.-Ph. Bernard, Álvaro Ribas, Vera Könyves, Pierre Didelon, K. L. J. Rygl, P. Palmeirim, Göran Pilbratt, C. Alves de Oliveira, Ph. André, Alexander Men'shchikov, Nick L. J. Cox, C. Waelkens, Ágnes Kóspál, Bruno Merín, Doris Arzoumanian, R. Vavrek, Nicola Schneider, Sylvain Bontemps, Timo Prusti, Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire arc électrique et plasmas thermiques (LAEPT), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Sécurité et Qualité des Produits d'Origine Végétale (SQPOV), Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre d'EPistémologie et d'ERgologie Comparatives (CEPERC), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], FORMATION STELLAIRE 2016, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Herschel Science Center [Madrid], European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP), European Space Agency (ESA), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), European Space Agency (ESA)-European Space Agency (ESA), Institut National de la Recherche Agronomique (INRA)-Avignon Université (AU), and Centre d'EPistémologie et d'ERgologie Comparatives - UMR 7304 (CEPERC)

Subjects
Physics, 010504 meteorology & atmospheric sciences, Field line, Molecular cloud, Astronomy, Astronomy and Astrophysics, Optical polarization, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Position angle, 01 natural sciences, Magnetic field, Protein filament, Stars, Space and Planetary Science, 0103 physical sciences, Substructure, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract

International audience; Herschel has shown that filamentary structures are ubiquitous in star-forming regions, in particular in nearby molecular clouds associated with Gould's Belt. High dynamic range far-infrared imaging of the Musca cloud with SPIRE and PACS reveals at least two types of filamentary structures: (1) the main ~10-pc scale high column-density linear filament; and (2) low column-density striations in close proximity to the main filament. In addition, we find features with intermediate column densities (hair-like strands) that appear physically connected to the main filament. We present an analysis of this filamentary network traced by Herschel and explore its connection with the local magnetic field. We find that both the faint dust emission striations and the plane-of-the-sky (POS) magnetic field are locally oriented close to perpendicular to the high-density main filament (position angle ~25-35°). The low-density striations and strands are oriented parallel to the POS magnetic field lines, which are derived previously from optical polarization measurements of background stars and more recently from Planck observations of dust polarized emission. The position angles are 97 ± 25°, 105 ± 7°, and 105 ± 5°. From these observations, we propose a scenario in which local interstellar material in this cloud has condensed into a gravitationally-unstable filament (with "supercritical" mass per unit length) that is accreting background matter along field lines through the striations. We also compare the filamentary structure in Musca with what is seen in similar Herschel observations of the Taurus B211/3 filament system and find that there is significantly less substructure in the Musca main filament than in the B211/3 filament. We suggest that the Musca cloud may represent an earlier evolutionary stage in which the main filament has not yet accreted sufficient mass and energy to develop a multiple system of intertwined filamentary components.Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Published
2016

21. Mission-level performance verification approach for the Euclid space mission

Author

Roberto Scaramella, Tom Kitching, Marc Sauvage, Anna Gregorio, J. Hoar, René J. Laureijs, Will J. Percival, Christophe Dabin, Guillermo Buenadicha, Stefanie Wachter, Andrea Zacchei, Yun Wang, Jose Lorenzo Alvarez, Bianca Garilli, Jérôme Amiaux, Jean Christophe Salvignol, Gonzalo Saavedra Criado, Ruyman Azzollini, Mark Cropper, Yannick Mellier, Martin Kilbinger, Giuseppe D. Racca, Anne Ealet, Luis M. Gaspar Venancio, Knud Jahnke, Henk Hoekstra, R. Vavrek, Angeli, George Z., Dierickx, Philippe, George Z. Angeli, Philippe Dierickx, Vavrek, Roland D., Laureijs, René J., Lorenzo Alvarez, Jose, Amiaux, Jérôme, Mellier, Yannick, Azzollini, Ruyman, Buenadicha, Guillermo, Saavedra Criado, Gonzalo, Cropper, Mark, Dabin, Christophe, Ealet, Anne, Garilli, Bianca, Gregorio, Anna, Hoekstra, Henk, Jahnke, Knud, Kilbinger, Martin, Kitching, Tom, Hoar, John, Percival, Will, Racca, Giuseppe D., Salvignol, Jean Christophe, Sauvage, Marc, Scaramella, Roberto, Gaspar Venancio, Luis M., Wang, Yun, Zacchei, Andrea, and Wachter, Stefanie

Subjects
Mission Database, Galactic astronomy, Condensed Matter Physic, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, law.invention, 010309 optics, Telescope, Euclid, parameter database, performance verification, Electronic, Optical and Magnetic Materials, Condensed Matter Physics, Computer Science Applications1707 Computer Vision and Pattern Recognition, Applied Mathematics, Electrical and Electronic Engineering, law, 0103 physical sciences, Electronic, Optical and Magnetic Materials, Aerospace engineering, 010303 astronomy & astrophysics, Weak gravitational lensing, Astrophysics::Galaxy Astrophysics, Photometric redshift, Physics, Spacecraft, Spectrometer, business.industry, Electronic, Optical and Magnetic Material, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Galaxy, Applied Mathematic, Dark energy, Astrophysics::Earth and Planetary Astrophysics, business
Abstract

ESA's Dark Energy Mission Euclid will map the 3D matter distribution in our Universe using two Dark Energy probes: Weak Lensing (WL) and Galaxy Clustering (GC). The extreme accuracy required for both probes can only be achieved by observing from space in order to limit all observational biases in the measurements of the tracer galaxies. Weak Lensing requires an extremely high precision measurement of galaxy shapes realised with the Visual Imager (VIS) as well as photometric redshift measurements using near-infrared photometry provided by the Near Infrared Spectrometer Photometer (NISP). Galaxy Clustering requires accurate redshifts (Δz/(z+1)

Published
2016

22. Is sky distribution of gamma-ray bursts random?

Author

Z. Bagoly, Gábor E. Tusnády, R. Vavrek, Péter Veres, Attila Mészáros, I. Horváth, and Lajos G. Balázs

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Monte Carlo method, Astronomy and Astrophysics, Function (mathematics), Multifractal system, Parameter space, Minimum spanning tree, Distribution (mathematics), Sky, Statistical physics, Instrumentation, Randomness, media_common
Abstract

We investigate the full randomness of the angular distribution of gamma-ray bursts (GRBs) detected by the BATSE (the Burst and Transient Source Experiment). We divided the BATSE sample into 5 subsamples (short1, short2, intermediate, long1, long2 based on their durations and peak fluxes and studied the angular distributions separately. We used three methods, the Voronoi tesselation, minimal spanning tree and multifractal spectra to search for non-randomness in the subsamples. To investigate the eventual non-randomness in the subsamples we defined 13 test-variables (9 from the Voronoi tesselation, 3 from the minimal spanning tree and one from the multifractal spectrum). We performed Monte Carlo simulations taking into account the BATSE sky-exposure function. We tested the randomness by introducing squared Euclidean distances in the parameter space of the test-variables. We concluded that the short1, short2 groups deviate significantly (99.90%, 99.98%) from the full randomness in the distribution of the squared Euclidean distances, however, it is not the case with the long subsamples. In the intermediate group, the squared Euclidean distances also yield a significant deviation (98.51%).

Published
2010

23. Discovery of Molecular Gas around HD 131835 in an APEX Molecular Line Survey of Bright Debris Disks

Author

Attila Juhasz, Th. Henning, Ilaria Pascucci, Timea Csengeri, Rolf Güsten, Gy. M. Szabó, P. Ábrahám, R. Vavrek, Carol A. Grady, Zoltan Balog, A. Moór, Cs. Kiss, Ágnes Kóspál, and Michel Curé

Subjects
Physics, Earth and Planetary Astrophysics (astro-ph.EP), Planetesimal, Debris disk, FOS: Physical sciences, Astronomy and Astrophysics, Radius, Astrophysics, Debris, Radio telescope, chemistry.chemical_compound, Stars, chemistry, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Stellar evolution, Solar and Stellar Astrophysics (astro-ph.SR), Carbon monoxide, Astrophysics - Earth and Planetary Astrophysics
Abstract

Debris disks are considered to be gas-poor, but recent observations revealed molecular or atomic gas in several 10-40 Myr old systems. We used the APEX and IRAM 30m radiotelescopes to search for CO gas in 20 bright debris disks. In one case, around the 16 Myr old A-type star HD 131835, we discovered a new gas-bearing debris disk, where the CO 3-2 transition was successfully detected. No other individual system exhibited a measurable CO signal. Our Herschel Space Observatory far-infrared images of HD 131835 marginally resolved the disk both at 70 and 100$\mu$m, with a characteristic radius of ~170 au. While in stellar properties HD 131835 resembles $\beta$ Pic, its dust disk properties are similar to those of the most massive young debris disks. With the detection of gas in HD 131835 the number of known debris disks with CO content has increased to four, all of them encircling young ($\leq$40 Myr) A-type stars. Based on statistics within 125 pc, we suggest that the presence of detectable amount of gas in the most massive debris disks around young A-type stars is a common phenomenon. Our current data cannot conclude on the origin of gas in HD 131835. If the gas is secondary, arising from the disruption of planetesimals, then HD 131835 is a comparably young and in terms of its disk more massive analogue of the $\beta$ Pic system. However, it is also possible that this system similarly to HD 21997 possesses a hybrid disk, where the gas material is predominantly primordial, while the dust grains are mostly derived from planetesimals., Comment: Accepted for publication in ApJ, 18 pages, 9 figures, 5 tables

Published
2015

24. HST/NICMOS observations of a proto-brown dwarf candidate

Author

Thomas Henning, Zoltán Kovács, R. Vavrek, Daniel Apai, L. V. Toth, and Dietrich Lemke

Subjects
Physics, Young stellar object, Astrophysics (astro-ph), Brown dwarf, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Young age, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present deep HST/NICMOS observations peering through the outflow cavity of the protostellar candidate IRAS 04381+2540 in the Taurus Molecular Cloud-1. A young stellar object as central source, a jet and a very faint and close (0.6") companion are identified. The primary and the companion have similar colours, consistent with strong reddening. We argue that the companion is neither a shock-excited knot nor a background star. The colour/magnitude information predicts a substellar upper mass limit for the companion, but the final confirmation will require spectroscopic information. Because of its geometry, young age and its rare low-mass companion, this system is likely to provide a unique insight into the formation of brown dwarfs., Astronomy & Astrophysics Letters, in press; 4 pages, 2 figures

Published
2005

25. A very young star forming region detected by the ISOPHOT Serendipity Survey

Author

R. Vavrek, Oliver Krause, Dietrich Lemke, L. V. Toth, Martin Haas, Manfred Stickel, and Ulrich Klaas

Subjects
Physics, Star formation, Infrared, Molecular cloud, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Star (graph theory), Accretion (astrophysics), Luminosity, Space and Planetary Science, Extinction (optical mineralogy), STAR model
Abstract

We present a multi-wavelength study of the star forming region ISOSS J 20298+3559, which was identified by a cross-correlation of cold compact sources from the 170 micron ISOPHOT Serendipity Survey (ISOSS) database coinciding with objects detected by the MSX, 2MASS and IRAS infrared surveys. ISOSS J 20298+3559 is associated with a massive dark cloud complex (M ~ 760 M$_{\odot}$) and located in the Cygnus X giant molecular cloud. We derive a distance of 1800 pc on the basis of optical extinction data. The low average dust temperature (T ~ 16 K) and large mass (M ~ 120 M$_{\odot}$) of the dense inner part of the cloud, which has not been dispersed, indicates a recent begin of star formation. The youth of the region is supported by the early evolutionary stage of several pre- and protostellar objects discovered across the regio n: I) Two candidate Class 0 objects with masses of 8 and 3.5 M$_{\odot}$, II) a gravitationally bound, cold (T ~ 12 K) and dense (n(H$_{2}$) \~ 2 x 10$^{5}$ cm$^{-3}$) cloud core with a mass of 50 M$_{\odot}$ and III) a Herbig B2 star with a mass of 6.5 M$_{\odot}$ and a bolometric luminosity of 2200 L$_{\odot}$, showing evidence for ongoing accretion and a stellar age of less than 40000 years. The dereddened SED of the Herbig star is well reproduced by an accretion disc + star model. The externally heated cold cloud core is a good candidate for a massive pre-protostellar object. The star formation efficiency in the central cloud region is about 14 %., 14 pages, 14 figures, 7 tables. Accepted for publication in Astronomy & Astrophysics

Published
2003

26. Euclid payload module: telescope characteristics and technical challenges

Author

René J. Laureijs, Jose Lorenzo, Ludovic Vaillon, Corrado Gennaro, Luis M. Gaspar Venancio, Jérôme Amiaux, Paolo Strada, Alex Short, R. Vavrek, Jean-Christophe Salvignol, and Eric Prieto

Subjects
Physics, Galactic astronomy, Payload, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Redshift, law.invention, Telescope, Galaxy groups and clusters, law, Dark energy, Baryon acoustic oscillations, Astrophysics::Galaxy Astrophysics, Weak gravitational lensing
Abstract

Euclid is an European Space Agency (ESA) mission to map the geometry of the dark Universe. The mission will investigate the distance-redshift relationship and the evolution of cosmic structures. It will achieve this by measuring shapes and redshifts of galaxies and clusters of galaxies out to redshifts ~2, equivalent to 10 billion years back in time. Euclid will make use of two primary cosmological probes, in a wide survey over the full extragalactic sky : the Weak Gravitational Lensing (WL) and Baryon Acoustic Oscillations (BAO). The main goal of the Euclid payload module (PLM) is to provide high quality imaging of galaxies and accurate measurement (less than 0.1%) of galaxies redshift over a large field of view (FoV). The present paper focuses on the telescope of the PLM excluding the instruments. We present a brief introduction to the Euclid PLM system and will report how the constraints of each instrument have driven the definition of the telescope-to-instrument optical interfaces. Furthermore we introduce the description of the telescope optical characteristics and report its nominal performances. Finally, the technical challenges to be faced by ESA’s industrial partners are underlined.

Published
2014

27. Herschel's view of the large-scale structure in the Chamaeleon dark clouds

Author

Álvaro Ribas, Pierre Didelon, C. Waelkens, Elena Puga, Vera Konyves, Sylvain Bontemps, Timo Prusti, Ágnes Kóspál, Nicola Schneider, L. Spezzi, Nick L. J. Cox, C. Alves de Oliveira, Alexander Men'shchikov, Göran Pilbratt, Elaine Winston, R. Royer, Doris Arzoumanian, R. Vavrek, Bruno Merín, Ph. André, FORMATION STELLAIRE 2014, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Agence Spatiale Européenne (ESA), European Space Agency (ESA), European Space Research and Technology Centre (ESTEC), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Agence Spatiale Européenne = European Space Agency (ESA), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, 010308 nuclear & particles physics, Turbulence, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Molecular cloud, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Protein filament, Stars, Computer Science::Systems and Control, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Scale structure, Log-normal distribution, Astrophysics::Solar and Stellar Astrophysics, Chamaeleon, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The Chamaeleon molecular cloud complex is one of the nearest star-forming sites encompassing three molecular clouds with a different star-formation history, from quiescent (Cha III) to actively forming stars (Cha II), and reaching the end of star-formation (Cha I). To charactize its large-scale structure, we derived column density and temperature maps using PACS and SPIRE observations from the Herschel Gould Belt Survey, and applied several tools, such as filament tracing, power-spectra, \Delta-variance, and probability distribution functions of column density (PDFs), to derive physical properties. The column density maps reveal a different morphological appearance for the three clouds, with a ridge-like structure for Cha I, a clump-dominated regime for Cha II, and an intricate filamentary network for Cha III. The filament width is measured to be around 0.12\pm0.04 pc in the three clouds, and the filaments found to be gravitationally unstable in Cha I and II, but mostly subcritical in Cha III. Faint filaments (striations) are prominent in Cha I showing a preferred alignment with the large-scale magnetic field. The PDFs of all regions show a lognormal distribution at low column densities. For higher densities, the PDF of Cha I shows a turnover indicative of an extended higher density component, culminating with a power-law tail. Cha II shows a power-law tail with a slope characteristic of gravity. The PDF of Cha III can be best fit by a single lognormal. The turbulence properties of the three regions are found to be similar, pointing towards a scenario where the clouds are impacted by large-scale processes. The magnetic field could possibly play an important role for the star-formation efficiency in the Chamaeleon clouds if proven that it can effectively channel material on Cha I, and possibly Cha II, but probably less efficiently on the quiescent Cha III cloud., Comment: Accepted for publication in A&A

Published
2014

28. The Herschel view of the massive star-forming region NGC 6334

Author

Lise Deharveng, Nicolas Peretto, Stefano Pezzuto, D. Polychroni, Volker Ossenkopf, D. Russeil, Q. Nguyen Luong, J. Tigé, J. Di Francesco, Tracey Hill, Luigi Spinoglio, Glenn J. White, Sergio Molinari, Doris Arzoumanian, Paolo Persi, Sylvain Bontemps, Ph. André, R. Vavrek, Nicola Schneider, L. D. Anderson, Pierre Didelon, Jin-Zeng Li, Kazi L.J. Rygl, Leonardo Testi, Vera Könyves, Annie Zavagno, M. Hennemann, Davide Elia, Peter G. Martin, J.-Ph. Bernard, Derek Ward-Thompson, H. Roussel, Frédérique Motte, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), FORMATION STELLAIRE 2013, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Herzberg Institute of Astrophysics, National Research Council of Canada (NRC), National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), Antarctic Research a European Network for Astrophysics (ARENA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Southern Observatory (ESO), School of Physics and Astronomy [Cardiff], Cardiff University, STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), 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), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)

Subjects
Gravity (chemistry), Star-forming complexes, Stars: formation, Astrophysics, 01 natural sciences, Power law, ISM: clouds, ISM : clouds, Using probabilities, ISM: individual objects: NGC 6334, Space applications, ISM: individual objects, 0103 physical sciences, 010303 astronomy & astrophysics, QB, Physics, 010308 nuclear & particles physics, Turbulence, Star formation, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Molecular cloud, Astronomy, Astronomy and Astrophysics, Density structures, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Wavelength, Probability distributions, Space and Planetary Science, Log-normal distribution, Probability distribution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Density distributions, Star-forming region, Distribution functions, Gravitation
Abstract

International audience; Aims: Fundamental to any theory of high-mass star formation are gravity and turbulence. Their relative importance, which probably changes during cloud evolution, is not known. By investigating the spatial and density structure of the high-mass star-forming complex NGC 6334 we aim to disentangle the contributions of turbulence and gravity. Methods: We used Herschel PACS and SPIRE imaging observations from the HOBYS key programme at wavelengths of 160, 250, 350, and 500 μm to construct dust temperature and column density maps. Using probability distribution functions (PDFs) of the column density determined for the whole complex and for four distinct sub-regions (distinguished on the basis of differences in the column density, temperature, and radiation field), we characterize the density structure of the complex. We investigate the spatial structure using the Δ-variance, which probes the relative amount of structure on different size scales and traces possible energy injection mechanisms into the molecular cloud. Results: The Δ-variance analysis suggests that the significant scales of a few parsec that were found are caused by energy injection due to expanding H ii regions, which are numerous, and by the lengths of filaments seen everywhere in the complex. The column density PDFs have a lognormal shape at low densities and a clearly defined power law at high densities for all sub-regions whose slope is linked to the exponent α of an equivalent spherical density distribution. In particular with α = 2.37, the central sub-region is largly dominated by gravity, caused by individual collapsing dense cores and global collapse of a larger region. The collapse is faster than free-fall (which would lead only to α = 2) and thus requires a more dynamic scenario (external compression, flows). The column density PDFs suggest that the different sub-regions are at different evolutionary stages, especially the central sub-region, which seems to be in a more evolved stage. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendix A is available in electronic form at http://www.aanda.org

Published
2013

29. Identification of transitional disks in Chamaeleon with Herschel

Author

Ágnes Kóspál, Álvaro Ribas, Elena Puga, Göran Pilbratt, Luca Matrà, Ph. André, Timo Prusti, C. Alves de Oliveira, Nick L. J. Cox, Bruno Merín, Hervé Bouy, David R. Ardila, R. Vavrek, and Loredana Spezzi

Subjects
Physics, Earth and Planetary Astrophysics (astro-ph.EP), education.field_of_study, Population, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Planetary system, Space observatory, Transitional phase, Identification (information), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Planet, Chamaeleon, Spectral energy distribution, Astrophysics::Earth and Planetary Astrophysics, education, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics
Abstract

Transitional disks are circumstellar disks with inner holes that in some cases are produced by planets and/or substellar companions in these systems. For this reason, these disks are extremely important for the study of planetary system formation. The Herschel Space Observatory provides an unique opportunity for studying the outer regions of protoplanetary disks. In this work we update previous knowledge on the transitional disks in the Chamaeleon I and II regions with data from the Herschel Gould Belt Survey. We propose a new method for transitional disk classification based on the WISE 12 micron-PACS 70 micron color, together with inspection of the Herschel images. We applied this method to the population of Class II sources in the Chamaeleon region and studied the spectral energy distributions of the transitional disks in the sample. We also built the median spectral energy distribution of Class II objects in these regions for comparison with transitional disks. The proposed method allows a clear separation of the known transitional disks from the Class II sources. We find 6 transitional disks, all previously known, and identify 5 objects previously thought to be transitional as possibly non-transitional. We find higher fluxes at the PACS wavelengths in the sample of transitional disks than those of Class II objects. We show the Herschel 70 micron band to be an efficient tool for transitional disk identification. The sensitivity and spatial resolution of Herschel reveals a significant contamination level among the previously identified transitional disk candidates for the two regions, which calls for a revision of previous samples of transitional disks in other regions. The systematic excess found at the PACS bands could be a result of the mechanism that produces the transitional phase, or an indication of different evolutionary paths for transitional disks and Class II sources., Comment: Accepted for publication in A&A: 11 March 2013 11 pages, 15 figures

Published
2013
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30. A resolved debris disk around the candidate planet-hosting star HD95086

Author

C. A. Grady, Th. Henning, Gy. M. Szabó, A. Moór, A. Kospal, Judit Szulágyi, Timea Csengeri, Zoltan Balog, Péter Ábrahám, Daniel Apai, Cs. Kiss, I. Pascucci, Attila Juhasz, and R. Vavrek

Subjects
Physics, Earth and Planetary Astrophysics (astro-ph.EP), Planetesimal, Debris disk, Infrared excess, Giant planet, FOS: Physical sciences, Astronomy and Astrophysics, Orbital eccentricity, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Planetary system, Fomalhaut, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Planet, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics
Abstract

Recently, a new planet candidate was discovered on direct images around the young (10-17 Myr) A-type star HD95086. The strong infrared excess of the system indicates that, similarly to HR8799, {\ss} Pic, and Fomalhaut, the star harbors a circumstellar disk. Aiming to study the structure and gas content of the HD95086 disk, and to investigate its possible interaction with the newly discovered planet, here we present new optical, infrared and millimeter observations. We detected no CO emission, excluding the possibility of an evolved gaseous primordial disk. Simple blackbody modeling of the spectral energy distribution suggests the presence of two spatially separate dust belts at radial distances of 6 and 64 AU. Our resolved images obtained with the Herschel Space Observatory reveal a characteristic disk size of ~6.0x5.4 arcsec (540x490 AU) and disk inclination of ~25 degree. Assuming the same inclination for the planet candidate's orbit, its re-projected radial distance from the star is 62 AU, very close to the blackbody radius of the outer cold dust ring. The structure of the planetary system at HD95086 resembles the one around HR8799. Both systems harbor a warm inner dust belt and a broad colder outer disk and giant planet(s) between the two dusty regions. Modelling implies that the candidate planet can dynamically excite the motion of planetesimals even out to 270 AU via their secular perturbation if its orbital eccentricity is larger than about 0.4. Our analysis adds a new example to the three known systems where directly imaged planet(s) and debris disks co-exist., Comment: Accepted for publication in ApJ Letters, 6 pages, 2 figures, 3 tables (emulateapj style)

Published
2013
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31. The Herschel Gould Belt Survey in Chamaeleon II - Properties of cold dust in disks around young stellar objects

Author

Ph. André, E. Winston, Álvaro Ribas, Loredana Spezzi, Ágnes Kóspál, Alexander Men'shchikov, Göran Pilbratt, Eli Bressert, Nick L. J. Cox, Pierre Royer, R. Vavrek, Luca Ricci, Bruno Merín, V. Könyves, Leonardo Testi, Timo Prusti, and C. Alves de Oliveira

Subjects
010504 meteorology & atmospheric sciences, Young stellar object, Brown dwarf, FOS: Physical sciences, Class iii, Astrophysics, 01 natural sciences, 0103 physical sciences, Radiative transfer, pre-main sequence [stars], 010303 astronomy & astrophysics, miscellaneous [instrumentation], Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Physics, stars [infrared], protoplanetary disks, Astronomy and Astrophysics, Stars, Spire, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Chamaeleon, individual objects: Chamaeleon II [ISM], Degeneracy (mathematics), clouds [ISM]
Abstract

We report on the Herschel Gould Belt survey (HGBS) of ChaII, focusing on the detection of Class I to III young stellar objects (YSOs). We aim at characterizing the circumstellar material around these YSOs and understanding which disk parameters are most likely constrained by the new HGBS data. We recovered 29 out of the 63 known YSOs in ChaII with a detection in at least one of the PACS/SPIRE pass-bands: 3 Class I YSOs (i.e.,100%), 1 Flat source (i.e., 50%), 21 Class II objects (i.e., 55%), 3 Class III objects (i.e, 16%) and the unclassified source IRAS 12522-7640. We explore PACS/SPIRE colors of this sample and present modeling of their SEDs using the RADMC-2D radiative transfer code. We find that YSO colors are confined in specific regions of PACS/SPIRE color-color diagrams. These color ranges are expected to be only marginally contaminated by extragalactic sources and field stars and, hence, provide a useful YSO selection tool when applied altogether. We were able to model the SED of 26 out of the 29 detected YSOs. We discuss the degeneracy/limitations of our SED fitting results and adopt the Bayesian method to estimate the probability of different values for the derived disk parameters. The Cha II YSOs present typical disk inner radii around 0.1 AU. The lower limit to Rc is typically around 50 AU. The lower limits to Mdisk are proportional to the stellar masses with a typical 0.3% ratio, i.e., in the range estimated in the literature for young Class II stars and brown dwarfs across a broad range of stellar masses. The estimated flaring angles, although very uncertain, point towards rather flat disks (1+phi less than 1.2), as found for low-mass M-type YSO samples in other star forming regions. Thus, our results support the idea that disk properties show a dependence on stellar properties., Comment: 17 pages, 9 figures

Published
2013
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32. MANAGERIAL APPROACHES OF ENVIRONMENTAL PROJECTS: AN EMPIRICAL STUDY.

Author

P., Adamisin, R., Kotulic, L., Mura, I., Kravcakova Vozarova, and R., Vavrek

Subjects
PROJECT management, ENVIRONMENTAL protection, ECONOMIC development, FINANCIAL aid, STATISTICAL correlation
Abstract

Copyright of Polish Journal of Management Studies is the property of Czestochowa University of Technology, Faculty of Management and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2018
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33. A new Herschel view of the young star T54: not a transitional disk?

Author

Elena Puga, Álvaro Ribas, Luca Matrà, Timo Prusti, Ph. André, Pierre Royer, C. Alves de Oliveira, Nick L. J. Cox, Nuria Huélamo, Bruno Merín, Göran Pilbratt, R. Vavrek, and Ágnes Kóspál

Subjects
Physics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Planetary system, Position angle, Wavelength, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Planet, Spectral energy distribution, Chamaeleon, Astrophysics::Earth and Planetary Astrophysics, Spectroscopy, Image resolution, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

Context: Observations of transitional disks give us an understanding of the formation of planets and planetary systems such as our own. But care must be taken in the identification of such sources: the higher spatial resolution of the Herschel Space Observatory provides a new view on the origin of the far-infrared and sub-millimeter excesses observed. Aims: We review the nature of previously known transitional disks in the Chamaeleon I star-forming region with Herschel data. Methods: We analyze Herschel PACS and SPIRE images of the young star T54 together with ancillary images. We also analyze its spectral energy distribution and indications from optical and mid-infrared spectroscopy. Results: We detect extended emission in the PACS 70 \mu m image ~6" off source at a position angle of 196{\deg} from T54. The emission detected at longer wavelength (PACS 100, 160, SPIRE 250 and 350 \mu m) is also offset from the position of the star. This suggests that the excess observed in the far-infrared part of the SED is not fully associated with T54. Conclusions: Herschel images show that the far-infrared excess seen in T54 is not due to a transitional disk but to extended emission south-west of the source. The object still shows point-like and now downscaled excess at mid-infrared wavelengths, but its origin cannot be constrained without higher spatial resolution data. However, different indications point towards an evolved disk or extended unresolved emission close to the source., Comment: 5 pages, 2 figures, Accepted for publication in Astronomy & Astrophysics on 25 October 2012

Published
2012

35. Thermal and shape properties of asteroid (21) Lutetia from Herschel observations around the Rosetta flyby

Author

Bruno Altieri, Benoit Carry, Michael Kueppers, E. Dotto, B. Gónzalez-García, M. A. Barucci, A. Llorente, Thomas Mueller, M. Sanchez Portal, Dominique Bockelée-Morvan, P. Garcia-Lario, M. Sierra, J. Crovisier, A. P. Marston, I. Valtchanov, R. Lorente, Laurence O'Rourke, Kathrin Altwegg, R. Schulz, R. Vavrek, B. Bhattacharya, D. Teyssier, Olivier Groussin, M. R. Kidger, Laurent Jorda, Herschel Science Centre, European Space Agency (ESA), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), European Space Astronomy Centre (ESAC), School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Physikalisches Institut [Bern], Universität Bern [Bern], 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, 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), INAF - Osservatorio Astronomico di Roma (OAR), Istituto Nazionale di Astrofisica (INAF), ISO Data Centre (ESA - Espagne), Herschel Science Centre (ESA Espagne), Haematology Service, University Hospital Joan XXIII, IISPV, Rovira and Virgili University, University of Utrecht, Utrecht University [Utrecht], Herschel Science Center [Madrid], European Space Agency (ESA)-European Space Agency (ESA), Agence Spatiale Européenne = European Space Agency (ESA), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern] (UNIBE), and Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA)

Subjects
[PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, Infrared, Astronomy, Astronomy and Astrophysics, Observable, Photometer, Albedo, 01 natural sciences, law.invention, Far infrared, Impact crater, 13. Climate action, Space and Planetary Science, Asteroid, law, Geometric albedo, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract

International audience; Prior to and around the Rosetta flyby of (21) Lutetia, the Herschel Space Observatory performed a collaborative observation campaign with its two photometers observing the asteroid in the far infrared, at wavelengths not covered by Rosetta's instruments. The Herschel observations, fed into a thermophysical model (TPM) using as input a shape model based on in-situ images, were also further correlated with similar to 70 multi-wavelength observations of Lutetia. We confirm the geometric albedo measured by Rosetta, derive a H-mag value based upon the effective diameter of the asteroid and point to (21) Lutetia having an extremely low thermal inertia (5J m(-2) s(-0.5) K-1). This thermal inertia is only possible through the existence of a significant amount of small scale roughness which is not directly observable by the OSIRIS (Optical, Spectroscopic, and Infrared Imaging System) instrument on-board Rosetta. In addition, our results point to the existence of a hill/crater surface feature located on the asteroids southern region not observed by Rosetta. From our results, we conclude that only through the merging of in situ and remote sensing observations can a true global picture be obtained of this asteroid. (C) 2012 Elsevier Ltd. All rights reserved.

Published
2012

36. The dusty environment of HD 97300 as seen by Herschel and Spitzer

Author

Álvaro Ribas, Pierre Royer, Nick L. J. Cox, Göran Pilbratt, Ágnes Kóspál, R. Vavrek, C. Alves de Oliveira, Timo Prusti, E. Winston, Bruno Merín, Christoffel Waelkens, and Ph. André

Subjects
Physics, Infrared excess, Opacity, Infrared, FOS: Physical sciences, Spectral density, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Interstellar medium, Stars, Wavelength, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Chamaeleon, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

Aims. We analyze the surroundings of HD 97300, one of two intermediate-mass stars in the Chamaeleon I star-forming region. The star is known to be surrounded by a conspicuous ring of polycyclic aromatic hydrocarbons (PAHs). Methods. We present infrared images taken with Herschel and Spitzer using 11 different broad-band filters between 3.6 um and 500 um. We compare the morphology of the emission using cuts along different position angles. We construct spectral energy distributions, which we compare to different dust models, and calculate dust temperatures. We also derive opacity maps and analyze the density structure of the environment of HD 97300. Results. We find that HD 97300 has no infrared excess at or below 24 um, confirming its zero-age main-sequence nature. The morphology of the ring is very similar between 3.6 um and 24 um. The emission at these wavelengths is dominated by either PAH features or PAH continuum. At longer wavelengths, only the northwestern part of the ring is visible. A fit to the 100-500 um observations suggests that the emission is due to relatively warm (~26 K) dust. The temperature gradually decreases with increasing distance from the ring. We find a general decrease in the density from north to south, and an approximate 10% density increase in the northeastern part of the ring. Conclusions. Our results are consistent with the theory that the ring around HD 97300 is essentially a bubble blown into the surrounding interstellar matter and heated by the star., 6 pages, 3 figures, accepted for publication in A&A

Published
2012

38. Initial highlights of the HOBYS key program, the Herschel imaging survey of OB young stellar objects

Author

Annie Zavagno, Nicola Schneider, Sergio Molinari, Jason M. Kirk, Pierre Didelon, Timea Csengeri, Zoltan Balog, L. D. Anderson, Matthew Joseph Griffin, D. Russeil, Peter Charles Hargrave, S. J. Leeks, Adam Woodcraft, Marc Sauvage, Christine D. Wilson, Alain Abergel, M. Hennemann, Q. Nguyen-Luong, Vincent Minier, Maohai Huang, J.-P. Baluteau, D. Teyssier, Pierrick Martin, Lise Deharveng, Alexander Men'shchikov, P. Persi, Derek Ward-Thompson, H. Roussel, Glenn J. White, Ph. André, Sylvain Bontemps, Leonardo Testi, S. Sadavoy, Pierre Cox, A. M. di Giorgio, Tracey Hill, R. Vavrek, Stefano Pezzuto, Luigi Spinoglio, Frédérique Motte, P. Saraceno, G. Olofsson, A. Marston, H. Aussel, Jin-Zeng Li, B. Sibthorpe, J. Di Francesco, J.-Ph. Bernard, Nicolas Peretto, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Herzberg Institute of Astrophysics, National Research Council of Canada (NRC), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), School of Physics and Astronomy [Cardiff], Cardiff University, STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), AUTRES, Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), CITA, University of Toronto, Stockholm University, Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Royal Observatory Edinburgh (ROE), University of Edinburgh, Antarctic Research a European Network for Astrophysics (ARENA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Southern Observatory (ESO), Herschel Science Center [Madrid], European Space Astronomy Centre (ESAC), European Space Agency (ESA)-European Space Agency (ESA), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), and School of Physics and Astronomy

Subjects
Physics, H II region, stars: formation, stars: protostars, 010308 nuclear & particles physics, Star formation, extinction, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Young stellar object, Astronomy, Astronomy and Astrophysics, telescopes, Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 01 natural sciences, stars: massive, H ii regions, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Protostar, dust, 010303 astronomy & astrophysics, QB
Abstract

International audience; We present the initial highlights of the HOBYS key program, which are based on Herschel images of the Rosette molecular complex and maps of the RCW120 H ii region. Using both SPIRE at 250/350/500 μm and PACS at 70/160 μm or 100/160 μm, the HOBYS survey provides an unbiased and complete census of intermediate- to high-mass young stellar objects, some of which are not detected by Spitzer. Key core properties, such as bolometric luminosity and mass (as derived from spectral energy distributions), are used to constrain their evolutionary stages. We identify a handful of high-mass prestellar cores and show that their lifetimes could be shorter in the Rosette molecular complex than in nearby low-mass star-forming regions. We also quantify the impact of expanding H ii regions on the star formation process acting in both Rosette and RCW 120. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Figures 4 and 5 are only available in electronic form at http://www.aanda.org

Published
2010

39. The Herschel first look at protostars in the Aquila Rift

Author

Matthew Joseph Griffin, Adam Woodcraft, Marc Sauvage, Stefano Pezzuto, Vera Könyves, Bruce Sibthorpe, Frédérique Motte, Vincent Minier, Doris Arzoumanian, Pierre Cox, Peter Charles Hargrave, P. Didelon, Nicolas Peretto, Annie Zavagno, Alexander Men'shchikov, J.-Ph. Bernard, Glenn J. White, Ph. André, Leonardo Testi, Bruno Merín, J. Di Francesco, Göran Olofsson, C. D. Wilson, R. Vavrek, M. Attard, Alain Abergel, Sylvain Bontemps, Maohai Huang, A. M. Di Giorgo, J.-P. Baluteau, Timo Prusti, P. Saraceno, Nicola Schneider, Jason M. Kirk, Anaëlle Maury, Derek Ward-Thompson, Peter Martin, Jin-Zeng Li, Sergio Molinari, Helene Roussel, D. Russeil, L. Spinoglio, L. Cambrésy, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), European Southern Observatory (ESO), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Herzberg Institute of Astrophysics, National Research Council of Canada (NRC), School of Physics and Astronomy [Cardiff], Cardiff University, National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), School of Physics and Astronomy, Photochimie moléculaire et macromoléculaire (PMM), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS), CITA, University of Toronto, Stockholm University, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Royal Observatory Edinburgh (ROE), University of Edinburgh, Antarctic Research a European Network for Astrophysics (ARENA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), University of Exeter, Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Rift, Serpens, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Global statistics, Spire, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Protostar, 010303 astronomy & astrophysics, Dust emission
Abstract

As part of the science demonstration phase of the Herschel mission of the Gould Belt Key Program, the Aquila Rift molecular complex has been observed. The complete ~ 3.3deg x 3.3deg imaging with SPIRE 250/350/500 micron and PACS 70/160 micron allows a deep investigation of embedded protostellar phases, probing of the dust emission from warm inner regions at 70 and 160 micron to the bulk of the cold envelopes between 250 and 500 micron. We used a systematic detection technique operating simultaneously on all Herschel bands to build a sample of protostars. Spectral energy distributions are derived to measure luminosities and envelope masses, and to place the protostars in an M_env - L_bol evolutionary diagram. The spatial distribution of protostars indicates three star-forming sites in Aquila, with W40/Sh2-64 HII region by far the richest. Most of the detected protostars are newly discovered. For a reduced area around the Serpens South cluster, we could compare the Herschel census of protostars with Spitzer results. The Herschel protostars are younger than in Spitzer with 7 Class 0 YSOs newly revealed by Herschel. For the entire Aquila field, we find a total of ~ 45-60 Class 0 YSOs discovered by Herschel. This confirms the global statistics of several hundred Class~0 YSOs that should be found in the whole Gould Belt survey., Comment: 6 pages, 6 figures, publication in A&A

Published
2010

40. Small-scale structure in the Rosette molecular cloud revealed by Herschel

Author

Alexander Men'shchikov, Jean-Paul Baluteau, B. Sibthorpe, Peter Charles Hargrave, J. Di Francesco, Nicola Schneider, Matthew Joseph Griffin, Jason M. Kirk, Pierre Didelon, R. Vavrek, Sarah Sadavoy, A. M. di Giorgio, Annie Zavagno, D. Teyssier, Sylvain Bontemps, Peter Timothy Cox, Luigi Spinoglio, Stefano Pezzuto, Jin-Zeng Li, Timea Csengeri, M. Hennemann, Zoltan Balog, Lise Deharveng, Pierrick Martin, P. Persi, P. Saraceno, Glenn J. White, Leonardo Testi, Ph. André, Sarah Leeks, Adam Woodcraft, Marc Sauvage, Sergio Molinari, Christine D. Wilson, Vincent Minier, Maohai Huang, D. Russeil, Frédérique Motte, Derek Ward-Thompson, J.-Ph. Bernard, G. Olofsson, A. Marston, Alain Abergel, Herzberg Institute of Astrophysics, National Research Council of Canada (NRC), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), School of Physics and Astronomy [Cardiff], Cardiff University, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), CITA, University of Toronto, Stockholm University, Royal Observatory Edinburgh (ROE), University of Edinburgh, Antarctic Research a European Network for Astrophysics (ARENA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Southern Observatory (ESO), Herschel Science Center [Madrid], European Space Astronomy Centre (ESAC), European Space Agency (ESA)-European Space Agency (ESA), University of Exeter, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), and School of Physics and Astronomy

Subjects
Physics, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Molecular cloud, Young stellar object, Continuum (design consultancy), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Space observatory, Rosette (botany), Spire, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Scale structure, Mass spectrum, 010303 astronomy & astrophysics, QB
Abstract

We present a preliminary analysis of the small-scale structure found in new 70-520 micron continuum maps of the Rosette molecular cloud (RMC), obtained with the SPIRE and PACS instruments of the Herschel Space Observatory. We find 473 clumps within the RMC using a new structure identification algorithm, with sizes up to ~1.0 pc in diameter. A comparison with recent Spitzer maps reveals that 371 clumps are "starless" (without an associated young stellar object), while 102 are "protostellar." Using the respective values of dust temperature, we determine the clumps have masses (M_C) over the range -0.75, 6 pages, to be published in Astronomy & Astrophysics

Published
2010

41. From filamentary clouds to prestellar cores to the stellar IMF: Initial highlights from the Herschel Gould Belt survey

Author

Alexander Men'shchikov, Pierre Cox, L. Cambrésy, Jin-Zeng Li, Aurora Sicilia-Aguilar, Adam Woodcraft, Marc Sauvage, A. Di Giorgio, Nicola Schneider, Stefano Pezzuto, J. Di Francesco, Jason M. Kirk, Timo Prusti, Alain Abergel, D. Russeil, Helene Roussel, Milena Benedettini, Pierre Royer, Bruce Sibthorpe, C. Waelkens, Th. Henning, J.-P. Baluteau, L. Spinoglio, Vincent Minier, Frédérique Motte, Doris Arzoumanian, Glenn J. White, R. Vavrek, Annie Zavagno, Vera Könyves, Ph. André, Peter Charles Hargrave, Sergio Molinari, M. Attard, Nicolas Peretto, P. Didelon, Sylvain Bontemps, Martin Hennemann, Ralf Launhardt, Oliver Krause, Leonardo Testi, Peter G. Martin, Bruno Merín, J. Le Pennec, J.-Ph. Bernard, Maohai Huang, Herve Aussel, Anaëlle Maury, C. D. Wilson, S. J. Leeks, Matthew Joseph Griffin, Peter A. R. Ade, Derek Ward-Thompson, Paolo Saraceno, Alain Omont, Joris Blommaert, Göran Olofsson, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), School of Physics and Astronomy [Cardiff], Cardiff University, Herzberg Institute of Astrophysics, National Research Council of Canada (NRC), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), European Southern Observatory (ESO), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), LEOSPHERE France, LEOSPHERE, AUTRES, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), School of Physics and Astronomy, CITA, University of Toronto, Stockholm University, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Royal Observatory Edinburgh (ROE), University of Edinburgh, Antarctic Research a European Network for Astrophysics (ARENA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), ITA, GBR, FRA, DEU, and BEL

Subjects
Physics, Gravitational instability, Initial mass function, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Molecular cloud, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, 01 natural sciences, law.invention, Spire, Polaris, Space and Planetary Science, law, Astrophysics of Galaxies (astro-ph.GA), Core formation, 0103 physical sciences, Protostar, 010303 astronomy & astrophysics, Flare, QB
Abstract

We summarize the first results from the Gould Belt survey, obtained toward the Aquila Rift and Polaris Flare regions during the 'science demonstration phase' of Herschel. Our 70-500 micron images taken in parallel mode with the SPIRE and PACS cameras reveal a wealth of filamentary structure, as well as numerous dense cores embedded in the filaments. Between ~ 350 and 500 prestellar cores and ~ 45-60 Class 0 protostars can be identified in the Aquila field, while ~ unbound starless cores and no protostars are observed in the Polaris field. The prestellar core mass function (CMF) derived for the Aquila region bears a strong resemblance to the stellar initial mass function (IMF), already confirming the close connection between the CMF and the IMF with much better statistics than earlier studies. Comparing and contrasting our Herschel results in Aquila and Polaris, we propose an observationally-driven scenario for core formation according to which complex networks of long, thin filaments form first within molecular clouds, and then the densest filaments fragment into a number of prestellar cores via gravitational instability., 7 pages, 4 figures. Accepted for publication in Astronomy and Astrophysics, Herschel Special Issue

Published
2010

42. Echo-planar imaging of intravoxel incoherent motion

Author

L K Hedges, James J. Pekar, D. Le Bihan, Robert Turner, J Maier, R Vavrek, Le Bihan, Denis, Service NEUROSPIN (NEUROSPIN), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, IFR de Neuroimagerie Fonctionnelle (IFR 49), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), National Institutes of Health [Bethesda] (NIH), GMD - Forschungszentrum Informationstechnik GmbH (GMD), Federal Republic of Germany, Department of Applied Mathematics and Statistics, Faculty of Mathematics Physis and Informatics, Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
[SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Anisotropic diffusion, Perfusion scanning, Signal, Imaging phantom, MESH: Magnetic Resonance Imaging, 030218 nuclear medicine & medical imaging, Diffusion, White matter, MESH: Brain, 03 medical and health sciences, MESH: Body Water, 0302 clinical medicine, Nuclear magnetic resonance, Body Water, Animals, Humans, Medicine, MESH: Animals, Radiology, Nuclear Medicine and imaging, Diffusion (business), Intravoxel incoherent motion, MESH: Humans, business.industry, Brain, MESH: Diffusion, MESH: Cerebrovascular Circulation, Magnetic Resonance Imaging, [SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, medicine.anatomical_structure, Cerebrovascular Circulation, Cats, MESH: Cats, business, Perfusion, 030217 neurology & neurosurgery
Abstract

International audience; The recently established single-shot technique of echo-planar imaging of intravoxel incoherent motion (IVIM) for determining and imaging the variations of microscopic motions of water has been applied to studies of water perfusion in phantoms and to in vivo studies of diffusion and perfusion in cat and human brains. The phantom results demonstrate that perfusion levels comparable with those found in vivo have easily observable and reproducible effects on signal amplitude that are consistent with previous IVIM theory. Reliable measurements of the diffusion coefficient in various types of brain tissue have been obtained. The results for white matter are consistent with the existence of anisotropic diffusion in oriented bundles of myelinated nerve fibers. The results for gray matter can be fitted to the IVIM theory and suggest a value of up to 14% for the fraction of the signal contributed by randomly perfusing fluid in normal cerebral cortex.

Published
1990

43. The Results of Statistical Tests of the Angular Distribution of Gamma-Ray Bursts

Author

R. Vavrek, Attila Mészáros, Lajos G. Balázs, Z. Bagoly, and I. Horváth

Subjects
Physics, Distribution (mathematics), Sky, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Isotropy, Multifractal system, Astrophysics, Minimum spanning tree, Gamma-ray burst, Anisotropy, media_common, Statistical hypothesis testing
Abstract

The spherical variants of multiscale methods — Voronoi tesselation, minimal spanning tree, and multifractal analysis — are used to test the angular distributions of three subgroups of gamma‐ray bursts (GRBs) collected in BATSE Gamma‐Ray Burst Catalog. They verify the isotropy of the sky distribution of gamma‐ray bursts. The short — in some tests also the intermediate — subclass exhibit anisotropic distribution. The distribution of long subclass seems to be isotropic.

Published
2003

44. HERSCHEL/PACS SPECTROSCOPIC SURVEY OF PROTOSTARS IN ORION: THE ORIGIN OF FAR-INFRARED CO EMISSION

Author

William J. Fischer, T. L. Wilson, S. T. Megeath, Charles A. Poteet, P. Manoj, Vincent Yu, John J. Tobin, Babar Ali, Dan M. Watson, Ruud Visser, Mayra Osorio, Sébastien Maret, Edwin Bergin, David A. Neufeld, R. Vavrek, J. Di Francesco, and Amelia M. Stutz

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Molecular cloud, FOS: Physical sciences, Astronomy and Astrophysics, Rotational temperature, Astrophysics, Astrophysics - Astrophysics of Galaxies, Spectral line, Stars, Astrophysics - Solar and Stellar Astrophysics, Far infrared, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Excited state, Astrophysics::Solar and Stellar Astrophysics, Protostar, Emission spectrum, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

We present far-IR (57-196 mu) spectra of 21 protostars in the Orion molecular clouds, obtained with the Photodetector Array Camera and Spectrometer (PACS) onboard the Herschel Space observatory, as part of the Herschel Orion Protostar Survey (HOPS) program. We analyzed the CO emission lines (J_up = 14-46) in the PACS spectra, extracted within a projected distance of = 2000 K). Our results suggest that the contribution from PDRs along the envelope cavity walls is unlikely to be the dominant component of the CO emission observed with PACS. Instead, the "universality" of the rotational temperatures and the observed correlation between L(CO) and L_bol can most easily be explained if the observed CO emission originates in shock-heated, hot (T >= 2000 K), sub-thermally excited (n(H_2) = several 100-1000 AU., 30 pages, 20 figures, 4 tables, accepted for publication in ApJ

Published
2013

45. Herschelfar-IR observations of the Chamaeleon molecular cloud complex

Author

Timo Prusti, Pierre Royer, Ágnes Kóspál, E. Winston, Göran Pilbratt, Álvaro Ribas, Vera Könyves, Ph. André, Alexander Men'shchikov, Elena Puga, C. Waelkens, Nick L. J. Cox, C. Alves de Oliveira, Bruno Merín, and R. Vavrek

Subjects
Physics, Stars, Space and Planetary Science, Star formation, Molecular cloud, Young stellar object, Chamaeleon, Protostar, Astronomy, Astronomy and Astrophysics, Astrophysics, Stellar evolution, Galaxy
Abstract

Context. The Herschel Gould Belt survey of nearby star forming regions is providing great insights into the early stages of the formation and the evolution of stars and their circumstellar disks. The Chamaeleon I dark cloud is an elongated region of dense dust and gas where star formation is ongoing in two centres, a northern region centred on Ced 112 and a southern cluster subdivided into the two regions Ced 110 and 111. Aims. In this initial study we present Herschel data of previously identified young stellar objects (YSOs) in the cluster, focusing on the spatial distribution of the YSOs and the determination of the relative colours of the protostars and the disk-bearing stars in Chamaeleon I. Methods. Chamaeleon I has been observed as part of the Herschel Gould Belt Survey, using the PACS and SPIRE parallel mode imaging at 70, 160, 250, 350, and 500 μm. Source extraction was performed using the getsources software. Results. We have detected 397 sources over the five available PACS and SPIRE bands, and through comparison with previously identified objects in the cluster we have identified 49 YSOs, 4 bright nebular emission features, five CO clumps, and twenty-eight candidate prestellar or starless cores in the Herschel sample. The remaining sample consists of candidate prestellar cores, condensations within the cloud, or background galaxies. The Herschel detected YSOs are highly clustered and mainly associated with the three known Cederblad groups. The observations clearly show that the young stars are forming coincident with the denser regions of cold dust and gas, visible at longer Herschel wavelengths. Those YSOs detected with Herschel were found to have an IRAC m3.6 μm < 10. No difference was found in the Herschel colours between the class I and class II young stars, however the class I sources were brighter than the class II at most Herschel wavelengths. One class III star and three transition disks are detected.

Published
2012

46. The Photodetector Array Camera and Spectrometer (PACS) on the HerschelSpace Observatory

Author

Jutta Stegmaier, Reinhard O. Katterloher, N. Belbachir, Erich Wiezorrek, Reinhard Genzel, Jürgen Schreiber, N. Billot, Stefano Pezzuto, Jean-Marie Gillis, E. Callut, Ybe Creten, C. Waelkens, E. Wieprecht, Benoit Marquet, J.-L. Augueres, Pierre Royer, Bruno Altieri, C. Cara, Claude Jamar, P. Saraceno, Thomas Henning, K. Okumura, L. Rodriguez, J. Schubert, G. Tofani, Albrecht Poglitsch, L. Duband, J. Martignac, Alessandra Contursi, V. Reveret, J. M. Herreros, Suzanne C. Madden, C. Jean, Norbert Geis, S. Regibo, Patrick Merken, Paola Andreani, Csaba Kiss, M. Thiel, A. Mazy, Zoltan Balog, P. Agnese, D. Cesarsky, D. Schmitt, Francis Montfort, W. De Meester, Thomas Müller, Marc Sauvage, L. Barl, Babar Ali, B. Vandenbussche, Dietrich Lemke, Joris Blommaert, Oliver Krause, V. Doublier, Gerhard Jakob, Ulrich Klaas, M. Benedettini, J. de Jong, O. Boulade, C. Van Hoof, Dieter Lutz, Massimo Inguscio, E. Doumayrou, Markus Nielbock, R. Orfei, Rik Huygen, Jan Putzeys, Horst Bischof, R. Cerulli, M. Wetzstein, Roland Ottensamer, E. Sturm, L. Morbidelli, Paola Popesso, Etienne Renotte, Otto H. Bauer, J. Cepa, Katrina Exter, Helmut Feuchtgruber, Franz Kerschbaum, R. Vavrek, and Ulrich Grözinger

Subjects
Physics, Spectrometer, business.industry, Bolometer, FOS: Physical sciences, Photodetector, Astronomy and Astrophysics, Field of view, law.invention, Photometry (optics), Optics, Far infrared, Space and Planetary Science, Observatory, law, Spectral resolution, Astrophysics - Instrumentation and Methods for Astrophysics, business, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

The Photodetector Array Camera and Spectrometer (PACS) is one of the three science instruments on ESA's far infrared and submillimetre observatory. It employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16×25 pixels, each, and two filled silicon bolometer arrays with 16×32 and 32×64 pixels, respectively, to perform integral-field spectroscopy and imaging photometry in the 60-210 μm wavelength regime. In photometry mode, it simultaneously images two bands, 60-85 μm or 85-125 μm and 125-210 μm, over a field of view of ~1.75'× 3.5', with close to Nyquist beam sampling in each band. In spectroscopy mode, it images a field of 47” × 47”, resolved into 5×5 pixels, with an instantaneous spectral coverage of ~1500 km s-1 and a spectral resolution of ~175 km s-1. We summarise the design of the instrument, describe observing modes, calibration, and data analysis methods, and present our current assessment of the in-orbit performance of the instrument based on the performance verification tests. PACS is fully operational, and the achieved performance is close to or better than the pre-launch predictions. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Published
2010

47. TheHerschelview of star formation in the Rosette molecular cloud under the influence of NGC 2244

Author

N. Schneider, F. Motte, S. Bontemps, M. Hennemann, J. Di Francesco, Ph. André, A. Zavagno, T. Csengeri, A. Men'shchikov, A. Abergel, J.-P. Baluteau, J.-Ph. Bernard, P. Cox, P. Didelon, A.-M. di Giorgio, R. Gastaud, M. Griffin, P. Hargrave, T. Hill, M. Huang, J. Kirk, V. Könyves, S. Leeks, J. Z. Li, A. Marston, P. Martin, V. Minier, S. Molinari, G. Olofsson, P. Panuzzo, P. Persi, S. Pezzuto, H. Roussel, D. Russeil, S. Sadavoy, P. Saraceno, M. Sauvage, B. Sibthorpe, L. Spinoglio, L. Testi, D. Teyssier, R. Vavrek, D. Ward-Thompson, G. White, C. D. Wilson, A. Woodcraft, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), School of Physics and Astronomy [Cardiff], Cardiff University, National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), CITA, University of Toronto, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Stockholm University, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Herzberg Institute of Astrophysics, National Research Council of Canada (NRC), Royal Observatory Edinburgh (ROE), University of Edinburgh, Antarctic Research a European Network for Astrophysics (ARENA), Herschel Science Center [Madrid], European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Consiglio Nazionale delle Ricerche (CNR), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), European Space Agency (ESA)-European Space Agency (ESA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), and School of Physics and Astronomy

Subjects
Density gradient, Population, FOS: Physical sciences, Astrophysics, Spatial distribution, 01 natural sciences, law.invention, Telescope, law, 0103 physical sciences, Radiative transfer, education, 010303 astronomy & astrophysics, QB, Physics, education.field_of_study, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 010308 nuclear & particles physics, Star formation, Molecular cloud, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Galaxy Astrophysics
Abstract

The Rosette molecular cloud is promoted as the archetype of a triggered star-formation site. This is mainly due to its morphology, because the central OB cluster NGC 2244 has blown a circular-shaped cavity into the cloud and the expanding HII-region now interacts with the cloud. Studying the spatial distribution of the different evolutionary states of all star-forming sites in Rosette and investigating possible gradients of the dust temperature will help to test the 'triggered star-formation' scenario in Rosette. We use continuum data obtained with the PACS (70 and 160 micron) and SPIRE instruments (250, 350, 500 micron) of the Herschel telescope during the Science Demonstration Phase of HOBYS. Three-color images of Rosette impressively show how the molecular gas is heated by the radiative impact of the NGC 2244 cluster. A clear negative temperature gradient and a positive density gradient (running from the HII-region/molecular cloud interface into the cloud) are detected. Studying the spatial distribution of the most massive dense cores (size scale 0.05 to 0.3 pc), we find an age-sequence (from more evolved to younger) with increasing distance to the cluster NGC 2244. No clear gradient is found for the clump (size-scale up to 1 pc) distribution. The existence of temperature and density gradients and the observed age-sequence imply that star formation in Rosette may indeed be influenced by the radiative impact of the central NGC 2244 cluster. A more complete overview of the prestellar and protostellar population in Rosette is required to obtain a firmer result., Letter in press for Astronomy & Astrophysics Herschel Special Issue

Published
2010

48. Diversity of B2 bradykinin receptors with nanomolar affinity expressed in passaged IMR90 human lung fibroblasts

Author

N L, Baenziger, Y J, Jong, S A, Yocum, L R, Dalemar, B, Wilhelm, R, Vavrek, and J M, Stewart

Subjects
Radioligand Assay, Receptors, Bradykinin, Molecular Sequence Data, Humans, Amino Acid Sequence, Kinins, Fibroblasts, Bradykinin, Lung, Cells, Cultured, Dinoprostone, Receptors, Neurotransmitter
Abstract

IMR90 human fetal lung fibroblasts express bradykinin receptors activating the pathway for biosynthesis of PGE2. A receptor of the B2 subtype stimulates half-maximal PGE2 production at 4.8 nM bradykinin, and maximal output takes place at 25 nM bradykinin. Radioligand binding studies reveal a population of [3H]bradykinin binding sites whose affinity correlates with this B2 receptor's biologic activity, with a KD of 2.5 nM. As IMR90 cells reach 60% of their defined life span in culture, they spontaneously induce expression of a second site of lower affinity, with half-maximal binding of [3H]bradykinin at 44 nM. This second site displays a characteristic primary B2 receptor recognition profile, but differs from the 2.5 nM site on a secondary level in recognition among different B2 ligands. Bradykinin is the most potent ligand at both sites; they each preferentially recognize an N-terminal extended bradykinin peptide construct having selectivity for the rat myometrial B2 receptor, suggesting that both sites have structural features in common. However, they display diversity in their order of preference for Met-Lys-bradykinin versus Lys-Lys-bradykinin; at the 44 nM site this order is completely reversed from the order of potency exhibited at the 2.5 nM site. Expression of the second site changes the manner in which these fibroblasts control their PGE2 production; it affords a graded response of PGE2 production at bradykinin levels beyond those which would normally saturate the 2.5 nM site. The inducibility of the 44 nM site in cultured fibroblasts addresses in vivo conditions in an inflammatory environment where continuing generation of bradykinin-related peptides takes place and presents a possible mechanism for overriding constraints that would otherwise limit the progression of inflammation.

Published
1992

49. Influence of a kinin antagonist on acute hypotensive responses induced by bradykinin and captopril in spontaneously hypertensive rats

Author

J N, Sharma, J M, Stewart, S S, Mohsin, M, Katori, and R, Vavrek

Subjects
Captopril, Time Factors, Dose-Response Relationship, Drug, Fluoroacetates, Receptors, Bradykinin, Blood Pressure, Bradykinin, Models, Biological, Rats, Receptors, Neurotransmitter, Heart Rate, Rats, Inbred SHR, Injections, Intravenous, Animals, Hypotension, Oligopeptides
Abstract

We have evaluated the effects of a B2 receptor antagonist (B5630) of kinins on BK and captopril-induced acute hypotensive responses in anaesthetized SHR. Intravenous treatment of BK (1.0 microgram) and captopril (0.3 mg/kg) caused significant (p0.05) fall in the SBP and DBP. Whereas BK caused greater fall in the SBP (p0.05), DBP (p0.01) and duration of hypotension (p0.05) when administered after captopril (Fig 1 and 2). All the hypotensive effects of BK and captopril were significantly antagonised (p0.05) in the presence of B5630 (2.0 mg/kg). Further, the duration of hypotensive responses of BK and captopril were blocked (p0.05) by B5630. The agonists and BK-antagonist did not cause significant (p0.05) alterations in HR during the entire investigation. These findings provide evidence to support the suggestion that B2 receptor might be involved in the regulation of the hypotensive actions of BK and captopril. Kinins should also have valuable functions in the antihypertensive property of captopril-like drugs.

Published
1992

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