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1. ALMA-IMF VI -- Investigating the origin of stellar masses: Core mass function evolution in the W43-MM2&MM3 mini-starburst

Author

Pouteau, Y., Motte, F., Nony, T., Gonzalez, M., Joncour, I., Robitaille, J. -F., Busquet, G., Galvan-Madrid, R., Gusdorf, A., Hennebelle, P., Ginsburg, A., Csengeri, T., Sanhueza, P., Dell'Ova, P., Stutz, A. M., Towner, A. P. M., Cunningham, N., Louvet, F., Men'shchikov, A., Fernandez-Lopez, M., Schneider, N., Armante, M., Bally, J., Baug, T., Bonfand, M., Bontemps, S., Bronfman, L., Brouillet, N., Diaz-Gonzalez, D., Herpin, F., Lefloch, B., Liu, H. -L., Lu, X., Nakamura, F., Luong, Q. Nguyen, Olguin, F., Tatematsu, K., and Valeille-Manet, M.

Subjects
Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences
Abstract

Among the most central open questions regarding the initial mass function (IMF) of stars is the impact of environment on the shape of the core mass function (CMF) and thus potentially on the IMF. The ALMA-IMF Large Program aims to investigate the variations in the core distributions with cloud characteristics, as diagnostic observables of the formation process and evolution of clouds. The present study focuses on the W43-MM2&MM3 mini-starburst, whose CMF has recently been found to be top-heavy with respect to the Salpeter slope. W43-MM2&MM3 harbors a rich cluster that contains a statistically significant number of cores, which was previously characterized in Paper III. We applied a multi-scale decomposition technique to the ALMA 1.3 mm and 3 mm continuum images to define six subregions. For each subregion we characterized the high column density probability distribution function, n-PDF, and the shape of the cloud gas using the 1.3 mm image. Using the core catalog, we investigate correlations between the CMF and cloud and core properties. We classify the subregions into different stages of evolution, from quiescent to burst to post-burst, based on the surface number density of cores, number of outflows, and UCHii presence. The high-mass end of the subregion CMFs varies from being close to the Salpeter slope (quiescent) to top-heavy (burst and post-burst). Moreover, the second tail of the n-PDF varies from steep, to flat like observed for the high mass star-forming clouds. We found that subregions with flat second n-PDF tails display top-heavy CMFs. The CMF may evolve from Salpeter to top-heavy throughout the star formation process from the quiescent to the burst phase. This scenario raises the question of if the CMF might revert again to Salpeter as the cloud approaches the end of its star formation stage, a hypothesis that remains to be tested., Accepted for publication in A&A (december, 5th 2022) after language editing; 25 pages, 14 figures

Published
2022
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2. ALMA-IMF III -- Investigating the origin of stellar masses: Top-heavy core mass function in the W43-MM2&MM3 mini-starburst

Author

Pouteau, Y., Motte, F., Nony, T., Galván-Madrid, R., Men'shchikov, A., Bontemps, S., Robitaille, J. -F., Louvet, F., Ginsburg, A., Herpin, F., López-Sepulcre, A., Dell'Ova, P., Gusdorf, A., Sanhueza, P., Stutz, A. M., Brouillet, N., Thomasson, B., Armante, M., Baug, T., Busquet, G., Csengeri, T., Cunningham, N., Fernández-López, M., Liu, H. -L., Olguin, F., Towner, A. P. M., Bally, J., Braine, J., Bronfman, L., Joncour, I., González, M., Hennebelle, P., Lu, X., Menten, K. M., Moraux, E., Tatematsu, K., Walker, D., and Whitworth, A. P.

Subjects
Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

The ALMA-IMF Large Program observed the W43-MM2-MM3 ridge, whose 1.3mm and 3mm ALMA 12m array continuum images reach a 2500au spatial resolution. We used both the best-sensitivity and the line-free ALMA-IMF images, reduced the noise with the multi-resolution segmentation technique MnGSeg, and derived the most complete and most robust core catalog possible. Using two different extraction software packages, getsf and GExt2D, we identified 200 compact sources, whose 100 common sources have on average fluxes consistent to within 30%. We filtered sources with non-negligible free-free contamination and corrected fluxes from line contamination, resulting in a W43-MM2-MM3 catalog of 205 getsf cores. With a median deconvolved FWHM size of 3400au, core masses range from 0.1Msun to 70Msun and the getsf catalog is 90% complete down to 0.8Msun. The high-mass end of the core mass function (CMF) of W43-MM2-MM3 is top-heavy compared to the canonical IMF. Fitting the cumulative CMF with a single power law of the form N(>logM)\propto M^a, we measured a=-0.95\pm0.04, compared to the canonical a=-1.35 Salpeter IMF slope. The slope of the CMF is robust with respect to map processing, extraction software package, and reasonable variations in the assumptions taken to estimate core masses. We explore several assumptions on how cores transfer their mass to stars and sub-fragment to predict the IMF resulting from the W43-MM2-MM3 CMF. In stark contrast to the commonly accepted paradigm, our result argues against the universality of the CMF shape. More robust functions of the star-formation efficiency and core sub-fragmentation are required to better predict the resulting IMF, here suggested to remain top-heavy at the end of the star-formation phase. If confirmed, the IMFs emerging from starburst events could inherit their top-heavy shape from their parental CMFs, challenging the IMF universality., 28 pages, 16 figures, 6 tables, A&A accepted on 02/08/22, revised following the language referee report

Published
2022
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3. ALMA-IMF

Author

Ginsburg, A., Csengeri, T., Galván-Madrid, R., Cunningham, N., Álvarez-Gutiérrez, R. H., Baug, T., Bonfand, M., Bontemps, S., Busquet, G., Díaz-González, D. J., Fernández-López, M., Guzmán, A., Herpin, F., Liu, H., López-Sepulcre, A., Louvet, F., Maud, L., Motte, F., Nakamura, F., Nony, T., Olguin, F. A., Pouteau, Y., Sanhueza, P., Stutz, A. M., Towner, A. P. M., Armante, M., Battersby, C., Bronfman, L., Braine, J., Brouillet, N., Chapillon, E., Di Francesco, J., Gusdorf, A., Izumi, N., Joncour, I., Walker Lu, X., Men’shchikov, A., Menten, K. M., Moraux, E., Molet, J., Mundy, L., Nguyen Luong, Q., Reyes-Reyes, S. D., Robitaille, J., Rosolowsky, E., Sandoval-Garrido, N. A., Svoboda, B., Tatematsu, K., Walker, D. L., Whitworth, A., Wu, B., Wyrowski, F., National Science Foundation (US), Consejo Nacional de Ciencia y Tecnología (México), Agence Nationale de la Recherche (France), European Research Council, European Commission, and Japan Society for the Promotion of Science

Subjects
HII regions, Instrumentation: interferometers, Space and Planetary Science, Mass function, ISM: structure, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Stars: luminosity function, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Astrophysics of Galaxies, Instrumentation and Methods for Astrophysics (astro-ph.IM), Stars: protostars
Abstract

A. Ginsburg et al., We present the first data release of the ALMA-IMF Large Program, which covers the 12m-array continuum calibration and imaging. The ALMA-IMF Large Program is a survey of fifteen dense molecular cloud regions spanning a range of evolutionary stages that aims to measure the core mass function. We describe the data acquisition and calibration done by the Atacama Large Millimeter/submillimeter Array (ALMA) observatory and the subsequent calibration and imaging we performed. The image products are combinations of multiple 12 m array configurations created from a selection of the observed bandwidth using multi-term, multi-frequency synthesis imaging and deconvolution. The data products are self-calibrated and exhibit substantial noise improvements over the images produced from the delivered data. We compare different choices of continuum selection, calibration parameters, and image weighting parameters, demonstrating the utility and necessity of our additional processing work. Two variants of continuum selection are used and will be distributed: the “best-sensitivity” (bsens) data, which include the full bandwidth, including bright emission lines that contaminate the continuum, and “cleanest” (cleanest), which select portions of the spectrum that are unaffected by line emission. We present a preliminary analysis of the spectral indices of the continuum data, showing that the ALMA products are able to clearly distinguish free-free emission from dust emission, and that in some cases we are able to identify optically thick emission sources. The data products are made public with this release., This paper makes use of the following ALMA data: ADS/JAO.ALMA#2017.1.01355.L and ADS/JAO.ALMA#2013.1.01365.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. A. G. acknowledges support from the National Science Foundation under grant AST-2008101. T. Cs. has received financial support from the French State in the framework of the IdEx Université de Bordeaux Investments for the future Program. R. G.-M. acknowledges support from UNAM-PAPIIT project IN104319 and from CONACyT Ciencia de Frontera project ID: 86372. R. A. gratefully acknowledges support from ANID Beca Doctorado Nacional 21200897. T. B. acknowledges the support from S. N. Bose National Centre for Basic Sciences under the Department of Science and Technology, Govt. of India. M. B. has received financial support from the French State in the framework of the IdEx Université de Bordeaux Investments for the future Program. S. B. acknowledges support by the French Agence Nationale de la Recherche (ANR) through the project GENESIS (ANR-16-CE92-0035-01). A. L. S., Y. P., and B. L. acknowledge funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme, for the Project “The Dawn of Organic Chemistry” (DOC), grant agreement No 741002. F. L. acknowledges the support of the Marie Curie Action of the European Union (project MagiKStar, Grant agreement number 841276). This project has received funding from the ERC under the European Union’s Horizon 2020 research and innovation programme (ECOGAL, grant agreement no. 855130). F. M. acknowledges the support of the French Agence Nationale de la Recherche (ANR) under reference ANR-20-CE31-0009, of the Programme National de Physique Stellaire and Physique et Chimie du Milieu Interstellaire (PNPS and PCMI) of CNRS/INSU (with INC/INP/IN2P3). P. S. was supported by a Grant-in-Aid for Scientific Research (KAKENHI Number 18H01259) of the Japan Society for the Promotion of Science (JSPS). P. S. and H.-L. L. gratefully acknowledge the support from the NAOJ Visiting Fellow Program to visit the National Astronomical Observatory of Japan in 2019, February. A.S. gratefully acknowledges funding support through Fondecyt Regular (project code 1180350) and from the Chilean Centro de Excelencia en Astrofísica y Tecnologías Afines (CATA) BASAL grant AFB-170002. C. B. and D. W. gratefully acknowledge support from the National Science Foundation under Award No. 1816715. L. B. acknowledges support from ANID BASAL grant AFB-170002. E. R. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada (NSERC), funding reference number RGPIN-2017-03987. B. W. was supported by a Grant-in-Aid for Scientific Research (KAKENHINumber18H01259)ofJapanSocietyforthePromotion of Science (JSPS). We thank the referee for a helpful and constructive report. The authors acknowledge University of Florida Research Computing for providing computational resources and support that have contributed to the research results reported in this publication. URL: https://www.rc.ufl.edu/. Part of this work was performed using the high-performance computers at IRyA-UNAM. Weacknowledge the investment over the years from CONACyT and UNAM, as well as the work from the IT staff of this institute.

Published
2021
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4. The accretion history of high-mass stars: An ArT��MiS pilot study of Infrared Dark Clouds

Author

Peretto, N., Rigby, A., Andr��, Ph., K��nyves, V., Fuller, G., Zavagno, A., Schuller, F., Arzoumanian, D., Bontemps, S., Csengeri, T., Didelon, P., Duarte-Cabral, A., Palmeirim, P., Pezzuto, S., Rev��ret, V., Roussel, H., and Shimajiri, Y.

Subjects
Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The mass growth of protostars is a central element to the determination of fundamental stellar population properties such as the initial mass function. Constraining the accretion history of individual protostars is therefore an important aspect of star formation research. The goal of the study presented here is to determine whether high-mass (proto)stars gain their mass from a compact (, 23 pages, 44 figures, accepted for publication in MNRAS

Published
2020
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5. Probing the cold magnetised Universe with SPICA-POL (B-BOP)

Author

André, Ph., Hughes, A., Guillet, V., Boulanger, F., Bracco, A., Ntormousi, E., Arzoumanian, D., Maury, A.J., Bernard, J.-Ph., Bontemps, S., Ristorcelli, I., Girart, J.M., Motte, F., Tassis, K., Pantin, E., Montmerle, T., Johnstone, D., Gabici, S., Efstathiou, A., Basu, S., Béthermin, M., Beuther, H., Braine, J., Francesco, J. Di, Falgarone, E., Ferrière, K., Fletcher, A., Galametz, M., Giard, M., Hennebelle, P., Jones, A., Kepley, A. A., Kwon, J., Lagache, G., Lesaffre, P., Levrier, F., Li, D., Li, Z.-Y., Mao, S. A., Nakagawa, T., Onaka, T., Paladino, R., Peretto, N., Poglitsch, A., Revéret, V., Rodriguez, L., Sauvage, M., Soler, J. D., Spinoglio, L., Tabatabaei, F., Tritsis, A., van der Tak, F., Ward-Thompson, D., Wiesemeyer, H., Ysard, N., Zhang, H., 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 recherche en astrophysique et planétologie (IRAP), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - 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), Foundation for Research and Technology - Hellas (FORTH), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Institut de Ciencies de l'Espai [Barcelona] (ICE-CSIC), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7 Canada, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), United States Nuclear Regulatory Commission (U.S.NRC), 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), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, 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), Herzberg Institute of Astrophysics, National Research Council of Canada (NRC), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), 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), University of Cambridge [UK] (CAM), Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Unité Matériaux et Transformations - UMR 8207 (UMET), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Iowa State University (ISU), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Università di Bologna [Bologna] (UNIBO), School of Physics and Astronomy [Cardiff], Cardiff University, Max Planck Institute for Extraterrestrial Physics (MPE), Telespazio, Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Institut für Physik (Institut für Physik), Universität Potsdam, Max-Planck-Institut für Radioastronomie (MPIFR), Institut de Chimie de Clermont-Ferrand - Clermont Auvergne (ICCF), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Sigma CLERMONT (Sigma CLERMONT), and Astronomy

Subjects
interstellar medium: structure, stars: formation, Astrophysics::Instrumentation and Methods for Astrophysics, observations: submillimeter, space missions, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, magnetic fields, Astrophysics::Galaxy Astrophysics
Abstract

International audience; Space Infrared Telescope for Cosmology and Astrophysics (SPICA), the cryogenic infrared space telescope recently pre-selected for a `Phase A' concept study as one of the three remaining candidates for European Space Agency (ESA's) fifth medium class (M5) mission, is foreseen to include a far-infrared polarimetric imager [SPICA-POL, now called B-fields with BOlometers and Polarizers (B-BOP)], which would offer a unique opportunity to resolve major issues in our understanding of the nearby, cold magnetised Universe. This paper presents an overview of the main science drivers for B-BOP, including high dynamic range polarimetric imaging of the cold interstellar medium (ISM) in both our Milky Way and nearby galaxies. Thanks to a cooled telescope, B-BOP will deliver wide-field 100-350 μm images of linearly polarised dust emission in Stokes Q and U with a resolution, signal-to-noise ratio, and both intensity and spatial dynamic ranges comparable to those achieved by Herschel images of the cold ISM in total intensity (Stokes I). The B-BOP 200 μm images will also have a factor 30 higher resolution than Planck polarisation data. This will make B-BOP a unique tool for characterising the statistical properties of the magnetised ISM and probing the role of magnetic fields in the formation and evolution of the interstellar web of dusty molecular filaments giving birth to most stars in our Galaxy. B-BOP will also be a powerful instrument for studying the magnetism of nearby galaxies and testing Galactic dynamo models, constraining the physics of dust grain alignment, informing the problem of the interaction of cosmic rays with molecular clouds, tracing magnetic fields in the inner layers of protoplanetary disks, and monitoring accretion bursts in embedded protostars.

Published
2019

6. Exposing the plural nature of molecular clouds : Extracting filaments and the CIB against the true scale-free interstellar medium

Author

Robitaille, J. -F., Motte, F., Schneider, N., Elia, D., and Bontemps, S.

Subjects
Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astrophysics - Astrophysics of Galaxies
Abstract

We present the Multiscale non-Gaussian Segmentation (MnGSeg) analysis technique. This wavelet based method combines the analysis of the probability distribution function (PDF) of map fluctuations as a function of spatial scales and the power spectrum analysis of a map. This technique allows us to extract the non-Gaussianities identified in the multiscaled PDFs usually associated with turbulence intermittency and to spatially reconstruct the Gaussian and the non-Gaussian component of the map. This new technique can be applied on any data set. Here, it is applied on a Herschel column density map of the Polaris flare cloud. The first component has by construction a self-similar fractal geometry as the one produced by fractional Brownian motion simulations. The second component is called the coherent component, by opposition to fractal, and includes a network of filamentary structures which demonstrates a spatial hierarchical scaling, i.e. filaments inside filaments. The power spectrum analysis of both components proves that the Fourier power spectrum of the initial map is dominated by the power of the coherent filamentary structures across almost all spatial scales. The coherent structures contribute progressively, more and more from large to smaller scales, without producing any break in the inertial range. We suggest that this behaviour is induced, at least partly, by inertial-range intermittency, a well known phenomenon for turbulent flows. We also demonstrate that the MnGSeg technique is a very sensitive signal analysis technique, which allows the extraction of the cosmic infrared background (CIB) signal present in the Polaris flare submillimeter observations and the detection of a characteristic scale for 0.1 < l < 0.3 pc whose origin could partly be the transition of regimes dominated by incompressible turbulence versus compressible modes and other physical processes, such as gravity., 17 pages, 16 figures. Submitted to A&A

Published
2019
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7. Probing the cold magnetised Universe with SPICA-POL (B-BOP)

Author

André, Ph, Hughes, A., Guillet, V., Boulanger, F., Bracco, A., Ntormousi, E., Arzoumanian, D., Maury, A. J., Bernard, J. Ph, Bontemps, S., Ristorcelli, I., Girart, J. M., Motte, F., Tassis, K., Pantin, E., Montmerle, T., Johnstone, D., Gabici, S., Efstathiou, A., Basu, S., Béthermin, M., Beuther, H., Braine, J., Di Francesco, J., Falgarone, E., Ferrière, K., Fletcher, A., Galametz, M., Giard, M., Hennebelle, P., and Jones, A.

Subjects
submillimeter [Observations], structure [Interstellar medium], Magnetic fields, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Space missions, Astrophysics::Galaxy Astrophysics, formation [Stars]
Abstract

Space Infrared Telescope for Cosmology and Astrophysics (SPICA), the cryogenic infrared space telescope recently pre-selected for a 'Phase A' concept study as one of the three remaining candidates for European Space Agency (ESA's) fifth medium class (M5) mission, is foreseen to include a far-infrared polarimetric imager [SPICA-POL, now called B-fields with BOlometers and Polarizers (B-BOP)], which would offer a unique opportunity to resolve major issues in our understanding of the nearby, cold magnetised Universe. This paper presents an overview of the main science drivers for B-BOP, including high dynamic range polarimetric imaging of the cold interstellar medium (ISM) in both our Milky Way and nearby galaxies. Thanks to a cooled telescope, B-BOP will deliver wide-field 100-350 µm images of linearly polarised dust emission in Stokes Q and U with a resolution, signal-to-noise ratio, and both intensity and spatial dynamic ranges comparable to those achieved by Herschel images of the cold ISM in total intensity (Stokes I). The B-BOP 200 µm images will also have a factor ∼30 higher resolution than Planck polarisation data. This will make B-BOP a unique tool for characterising the statistical properties of the magnetised ISM and probing the role of magnetic fields in the formation and evolution of the interstellar web of dusty molecular filaments giving birth to most stars in our Galaxy. B-BOP will also be a powerful instrument for studying the magnetism of nearby galaxies and testing Galactic dynamo models, constraining the physics of dust grain alignment, informing the problem of the interaction of cosmic rays with molecular clouds, tracing magnetic fields in the inner layers of protoplanetary disks, and monitoring accretion bursts in embedded protostars.

Published
2019

9. Core fragmentation and Toomre stability analysis of W3(H2O). A case study of the IRAM NOEMA large program CORE

Author

Ahmadi, A., Beuther, H., Mottram, J., Bosco, F., Linz, H., Henning, T., Winters, J., Kuiper, R., Pudritz, R., Sánchez-Monge, Á., Keto, E., Beltran, M., Bontemps, S., Cesaroni, R., Csengeri, T., Feng, S., Galvan-Madrid, R., Johnston, K., Klaassen, P., Leurini, S., Longmore, S., Lumsden, S., Maud, L., Menten, K., Moscadelli, L., Motte, F., Palau, A., Peters, T., Ragan, S., Schilke, P., Urquhart, J., Wyrowski, F., and Zinnecker, H.

Abstract

Context. The fragmentation mode of high-mass molecular clumps and the properties of the central rotating structures surrounding the most luminous objects have yet to be comprehensively characterised. Aims: We study the fragmentation and kinematics of the high-mass star- forming region W3(H2O), as part of the IRAM NOrthern Extended Millimeter Array (NOEMA) large programme CORE. Methods: Using the IRAM NOEMA and the IRAM 30 m telescope, the CORE survey has obtained high-resolution observations of 20 well-known highly luminous star- forming regions in the 1.37 mm wavelength regime in both line and dust continuum emission. Results: We present the spectral line setup of the CORE survey and a case study for W3(H2O). At 0.''35 (700 AU at 2.0 kpc) resolution, the W3(H2O) clump fragments into two cores (west and east), separated by 2300 AU. Velocity shifts of a few km s-1 are observed in the dense-gas tracer, CH3CN, across both cores, consistent with rotation and perpendicular to the directions of two bipolar outflows, one emanating from each core. The kinematics of the rotating structure about W3(H2O) W shows signs of differential rotation of material, possibly in a disk-like object. The observed rotational signature around W3(H2O) E may be due to a disk-like object, an unresolved binary (or multiple) system, or a combination of both. We fit the emission of CH3CN (12K-11K), K = 4-6 and derive a gas temperature map with a median temperature of 165 K across W3(H2O). We create a Toomre Q map to study thestability of the rotating structures against gravitational instability. The rotating structures appear to be Toomre unstable close to their outer boundaries, with a possibility of further fragmentation in the differentially rotating core, W3(H2O) W. Rapid cooling in the Toomre unstable regions supports the fragmentation scenario. Conclusions: Combining millimetre dust continuum and spectral line data toward the famous high-mass star-forming region W3(H2O), we identify core fragmentation on large scales, and indications for possible disk fragmentation on smaller spatial scales. Based on observations from an IRAM large program. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).Observational data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/qcat?J/A+A/618/A46, or alternatively at http://www.mpia.de/core.

Published
2018

10. Outflows, infall and evolution of a sample of embedded low-mass protostars

Author

Mottram, J. C., van Dishoeck, E. F., Kristensen, L. E., Karska, A., San José-García, I., Khanna, S., Herczeg, G. J., André, Ph., Bontemps, S., Cabrit, S., Carney, M. T., Drozdovskaya, M. N., Dunham, M. M., Evans, N. J., Fedele, D., Green, J. D., Harsono, D., Johnstone, D., Jørgensen, J. K., Könyves, V., Nisini, B., Persson, M. V., Tafalla, M., Visser, R., and Yıldız, U. A.

Published
2017
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11. Limited fragmentation at the early evolutionary stage of massive clumps⋆

Author

Csengeri, T., Bontemps, S., Wyrowski, F., Motte, F., Menten, K. M., Beuther, H., Bronfman, L., Commerçon, B., Chapillon, E., Duarte-Cabral, A., Fuller, G. A., Henning, Th., Leurini, S., Longmore, S., Palau, A., Peretto, N., Schuller, F., Tan, J. C., Testi, L., Traficante, A., and Urquhart, J. S.

Subjects
Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The early evolution of massive cluster progenitors is poorly understood. We investigate the fragmentation properties from 0.3 pc to 0.06 pc scales of a homogenous sample of infrared-quiet massive clumps within 4.5 kpc selected from the ATLASGAL survey. Using the ALMA 7 m array we detect compact dust continuum emission towards all targets and find that fragmentation, at these scales, is limited. The mass distribution of the fragments uncovers a large fraction of cores above 40 M⊙, corresponding to massive dense cores (MDCs) with masses up to ~400 M⊙. Seventy-seven percent of the clumps contain at most 3 MDCs per clump, and we also reveal single clumps/MDCs. The most massive cores are formed within the more massive clumps and a high concentration of mass on small scales reveals a high core formation efficiency. The mass of MDCs highly exceeds the local thermal Jeans mass, and we lack the observational evidence of a sufficiently high level of turbulence or strong enough magnetic fields to keep the most massive MDCs in equilibrium. If already collapsing, the observed fragmentation properties with a high core formation efficiency are consistent with the collapse setting in at parsec scales.

Published
2017
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12. Star formation towards the Galactic HII region RCW120

Author

Figueira, M., Zavagno, A., Deharveng, L., Russeil, D., Anderson, L. D., Men'shchikov, A., Schneider, N., Hill, T., Motte, F., Mège, P., Leleu, G., Roussel, H., Bernard, J-P., Traficante, A., Paradis, D., Tigé, J., André, P., Bontemps, S., and Abergel, A.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

The expansion of HII regions can trigger the formation of stars. An overdensity of young stellar objects (YSOs) is observed at the edges of HII regions but the mechanisms that give rise to this phenomenon are not clearly identified. Moreover, it is difficult to establish a causal link between HII-region expansion and the star formation observed at the edges of these regions. A clear age gradient observed in the spatial distribution of young sources in the surrounding might be a strong argument in favor of triggering. We have observed the Galactic HII region RCW120 with herschel PACS and SPIRE photometers at 70, 100, 160, 250, 350 and 500$\mu$m. We produced temperature and H$_2$ column density maps and use the getsources algorithm to detect compact sources and measure their fluxes at herschel wavelengths. We have complemented these fluxes with existing infrared data. Fitting their spectral energy distributions (SEDs) with a modified blackbody model, we derived their envelope dust temperature and envelope mass. We computed their bolometric luminosities and discuss their evolutionary stages. The herschel data, with their unique sampling of the far infrared domain, have allowed us to characterize the properties of compact sources observed towards RCW120 for the first time. We have also been able to determine the envelope temperature, envelope mass and evolutionary stage of these sources. Using these properties we have shown that the density of the condensations that host star formation is a key parameter of the star-formation history, irrespective of their projected distance to the ionizing stars.

Published
2016
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14. The first Galaxy scale hunt for the youngest high-mass protostars

Author

Simon, R., Csengeri, T., Bontemps, S., Wyrowski, F., Menten, K.M., Leurini, S., Urquhart, J.S., Motte, F., Schuller, F., Testi, L., Bronfman, L., Beuther, H., Longmore, S., Commerçon, B., Henning, Th., Palau, A., Tan, J.C., Fuller, G., Peretto, N., Duarte-Cabral, A., Traficante, A., Schaaf, R., Stutzki, J., 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), Max-Planck-Institut für Radioastronomie (MPIFR), Mars Desert Research Station (MDRS), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Departamento de Astronomia (DAS), Swinburne University of Technology (Hawthorn campus), Observatoire de Paris, Université Paris sciences et lettres (PSL), Centro de Radioastronomia y Astrofisica (CRyA), Universidad Nacional Autónoma de México (UNAM), Jodrell Bank Centre for Astrophysics (JBCA), University of Manchester [Manchester], 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 (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), Universidad de Santiago de Chile [Santiago] (USACH), School of Physics, PSL Research University (PSL), Centro de Radioastronomia y Astrofisica, Jodrell Bank Centre for Astrophysics, Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), 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, General Engineering, FOS: Physical sciences, Astronomy and Astrophysics, Scale (descriptive set theory), Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), High mass, Protostar, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Solar and Stellar Astrophysics (astro-ph.SR), O-type star, QB
Abstract

The origin of massive stars is a fundamental open issue in modern astrophysics. Pre-ALMA interferometric studies reveal precursors to early B to late O type stars with collapsing envelopes of 15-20 M$_\odot$ on 1000-3000 AU size-scales. To search for more massive envelopes we selected the most massive nearby young clumps from the ATLASGAL survey to study their protostellar content with ALMA. Our first results using the intermediate scales revealed by the ALMA ACA array providing 3-5" angular resolution, corresponding to $\sim$0.05-0.1 pc size-scales, reveals a sample of compact objects. These massive dense cores are on average two-times more massive than previous studies of similar types of objects. We expect that once the full survey is completed, it will provide a comprehensive view on the origin of the most massive stars., Comment: 4 pages, 1 figure, to appear in proceedings of The 6th Zermatt ISM Symposium: Conditions and Impact of Star Formation From Lab to Space, eds. R. Simon, M. Rollig

Published
2015
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15. ATLASGAL --- Complete compact source catalogue: 280\degr\ $

Author

Urquhart, J. S., Csengeri, T., Wyrowski, F., Schuller, F., Bontemps, S., Bronfman, L., Menten, K. M., Walmsley, C. M., Contreras, Y., Beuther, H., Wienen, M., and Linz, H.

Subjects
Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences
Abstract

The APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) is the largest and most sensitive systematic survey of the inner Galactic plane in the submillimetre wavelength regime. The observations were carried out with the Large APEX Bolometer Camera (LABOCA), an array of 295 bolometers observing at 870\,$��$m (345 GHz). Aim: In this research note we present the compact source catalogue for the 280\degr\ $, Submitted to A&A. Consists of 5 pages, 4 figures and one table. Only a small sample of Table 1 is given and the full table will be made available through CDS

Published
2014
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16. MALT90: The Millimetre Astronomy Legacy Team 90 GHz Survey

Author

Jackson, J. M., Rathborne, J. M., Foster, J. B., Whitaker, J. S., Sanhueza, P., Claysmith, C., Mascoop, J. L., Wienen, M., Breen, S. L., Herpin, F., Duarte-Cabral, A., Csengeri, T., Longmore, S., Contreras, Y., Indermuehle, B., Barnes, P. J., Walsh, A. J., Cunningham, M. R., Brooks, K. J., Britton, T. R., Voronkov, M. A., Urquhart, J. S., Alves, J., Jordan, C. H., Hill, T., Hoq, S., Finn, S., C., S., Bains, I., Bontemps, S., Bronfman, L., Caswell, J. L., Deharveng, L., Ellingsen, S. P., Fuller, G. A., Garay, G., Green, J. A., Hindson, L., Jones, P. A., Lenfestey, C., Lo, N., Lowe, V., Mardones, D., Menten, K. M., Minier, V., Morgan, L. K., Motte, F., Muller, E., Peretto, N., Purcell, C. R., Schilke, P., Schneider-Bontemps, N., Schuller, F., Titmarsh, A., Wyrowski, F., Zavagno, A., Max-Planck-Institut für Radioastronomie (MPIFR), FORMATION STELLAIRE 2013, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), 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), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (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), Swinburne University of Technology (Hawthorn campus), Laboratoire de Probabilités et Modèles Aléatoires (LPMA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Australia Telescope National Facility (ATNF), Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Instituto Dom Luiz, Universidade de Lisboa = University of Lisbon (ULISBOA), Departamento de Astronomia (DAS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, German Aerospace Center (DLR), Max Planck Institute for Radio Astronomy, I. Physikalisches Institut [Köln], Universität zu Köln = University of Cologne, 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), 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), School of Physics, Australia Telescope National Facility, Universidade de Lisboa (ULISBOA), Universidad de Santiago de Chile [Santiago] (USACH), Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, Univ Cologne, Inst Phys 1, Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Universität zu Köln

Subjects
Data products, High resolution, FOS: Physical sciences, Astrophysics, 01 natural sciences, law.invention, Telescope, law, 0103 physical sciences, 010303 astronomy & astrophysics, QB, Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 010308 nuclear & particles physics, Star formation, Astronomy, Astronomy and Astrophysics, Galactic plane, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, Large sample, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Millimeter, Galaxy Astrophysics, Data reduction
Abstract

The Millimetre Astronomy Legacy Team 90 GHz (MALT90) survey aims to characterise the physical and chemical evolution of high-mass star-forming clumps. Exploiting the unique broad frequency range and on-the-fly mapping capabilities of the Australia Telescope National Facility Mopra 22 m single-dish telescope, MALT90 has obtained 3' x 3' maps toward ~2000 dense molecular clumps identified in the ATLASGAL 870 um Galactic plane survey. The clumps were selected to host the early stages of high-mass star formation and to span the complete range in their evolutionary states (from prestellar, to protostellar, and on to HII regions and photodissociation regions). Because MALT90 mapped 16 lines simultaneously with excellent spatial (38") and spectral (0.11 km/s) resolution, the data reveal a wealth of information about the clump's morphologies, chemistry, and kinematics. In this paper we outline the survey strategy, observing mode, data reduction procedure, and highlight some early science results. All MALT90 raw and processed data products are available to the community. With its unprecedented large sample of clumps, MALT90 is the largest survey of its type ever conducted and an excellent resource for identifying interesting candidates for high resolution studies with ALMA., Comment: Accepted to PASA, 13 pages

Published
2013
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17. ATLASGAL - Compact source catalogue: 330 < l < 21 degrees

Author

Contreras, Y., Schuller, F., Urquhart, J. S., Csengeri, T., Wyrowski, F., Beuther, H., Bontemps, S., Bronfman, L., Henning, T., Menten, K. M., Schilke, P., Walmsley, C. M., Wienen, M., Tackenberg, J., and Linz, H.

Subjects
Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences
Abstract

Context. The APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) is the first systematic survey of the inner Galactic plane in the sub-millimetre. The observations were carried out with the Large APEX Bolometer Camera (LABOCA), an array of 295 bolometers observing at 870 microns (345 GHz). Aims. Here we present a first version of the compact source catalogue extracted from this survey. This catalogue provides an unbiased database of dusty clumps in the inner Galaxy. Methods. The construction of this catalogue was made using the source extraction routine SExtractor. We have cross-associated the obtained sources with the IRAS and MSX catalogues, in order to constrain their nature. Results. We have detected 6639 compact sources in the range from 330 < l < 21 degrees and |b| < 1.5 degrees. The catalogue has a 99% completeness for sources with a peak flux above 6 sigma, which corresponds to a flux density of ~0.4 Jy/beam. The parameters extracted for sources with peak fluxes below the 6 sigma completeness threshold should be used with caution. Tests on simulated data find the uncertainty in the flux measurement to be ~12%, however, in more complex regions the flux values can be overestimated by a factor of 2 due to the additional background emission. Using a search radius of 30" we found that 40% of ATLASGAL compact sources are associated with an IRAS or MSX point source, but, ~50% are found to be associated with MSX 21 microns fluxes above the local background level, which is probably a lower limit to the actual number of sources associated with star formation. Conclusions. Although infrared emission is found towards the majority of the clumps detected, this catalogue is still likely to include a significant number of clumps that are devoid of star formation activity and therefore excellent candidates for objects in the coldest, earliest stages of (high-mass) star formation., The full catalogue and the calibrated emission maps are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or via http://cdsweb.u-strasbg.fr/cgibin/qcat?J/A+A/

Published
2012
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21. Time-dependent accretion and ejection implied by pre-stellar density profiles

Author

Henriksen, R., Andre, P., and Bontemps, S.

Subjects
Astrophysics (astro-ph), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Recent observations suggest that mass ejection and mass accretion both decline significantly with time during early protostellar evolution (Bontemps et al. 1996). In the present paper, we propose that this rapid decay of accretion/ejection activity is a direct result of the non-singular density profiles characterizing pre-collapse clouds. The radial density profiles of pre-stellar cores are indeed found to be much flatter than rho(r) ~ r(-2) at radii less than a few thousand AU (Ward-Thompson et al. 1994). Here we show, through Lagrangian analytical calculations, that the supersonic gravitational collapse of pre-stellar cloud cores with centrally peaked, but flattened density profiles leads to a transitory phase of energetic accretion immediately following the formation of the central hydrostatic protostar. Physically, the flat inner region collapses first nearly homologously to form a finite mass stellar nucleus, and the remaining cloud core material then accretes supersonically onto a non-zero point mass. Enhanced accretion persists as long as the gravitational pull of this initial point mass, which does not exist in the Shu singular solution, remains significant. We suggest that this epoch of vigorous accretion coincides with Class 0 protostars, which would explain their unusually powerful jets compared to the more evolved Class I objects. We also use a simple two-component power-law model to fit the diagrams of outflow power versus envelope mass observed by Bontemps et al. (1996), and suggest that rho Ophiuchi and Taurus young stellar objects follow different accretion histories because of differing initial conditions., Comment: 18 pages, 10 figures, LaTeX (uses standard A&A macro), to appear in Astronomy and Astrophysics

Published
1997
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22. Accuracy assessment of a 300 m global land cover map: The GlobCover experience

Author

Defourny, P., Schouten, L., Bartalev, S., Bontemps, S., Caccetta, P., Wit, A. J. W., Di Bella, C., Gérard, B., Giri, C., Gond, V., Gerard Hazeu, Heinimann, A., Herold, M., Knoops, J., Jaffrain, G., Latifovic, R., Lin, H., Mayaux, P., Mücher, C. A., Nonguierma, A., Stibig, H. J., Bogaert, E., Vancutsem, C., Bicheron, P., Leroy, M., and Arino, O.

24. Characterisation of silicon carbide Schottky diodes and COOLMOS™ transistors at high temperature

Author

Laurent DUPONT, Lefebvre, S., Bontemps, S., Khatir, Z., Meuret, R., Laboratoire des Technologies Nouvelles (INRETS/LTN), Institut National de Recherche sur les Transports et leur Sécurité (INRETS), Systèmes et Applications des Technologies de l'Information et de l'Energie (SATIE), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École normale supérieure - Rennes (ENS Rennes)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Centre National de la Recherche Scientifique (CNRS), APT Europe, and Hispano Suiza

Subjects
SILICONE, RESISTANCE (MATER), ESSAI, COMPARAISON, SIMULATION, COMPORTEMENT, TEMPERATURE, COMPOSANT ELECTRONIQUE, TRANSISTOR, [SPI.MAT]Engineering Sciences [physics]/Materials, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract

PESC 04 - IEEE 35th annual Power Electronics Specialists Conference, AIX LA CHAPELLE, ALLEMAGNE, 20-/06/2004 - 25/06/2004; The highly doping level of the base region of COOLMOS transistors allows higher temperature operations than with conventional silicon transistors having the same blocking voltage. In this paper, the temperature influence on different SiC Schottky diodes and Silicon COOLMOS transistors characteristics is discussed. Comparisons are made between SiC Schottky diodes and Si PIN diodes and beween IGBTs, low voltage MOSFET and COOLMOSTM at high temperature. Results on the leakage current indicate the ability of SiC Schottky diodes and Si COOLMOS transistors to be used at temperature about 200 °C. The paper will present results on the behaviour of SiC schottky diodes and COOLMOS transistors in the on-state and in switching operations. Switching behaviour is analysed in a buck-chopper working in single shoot condition. Results show that temperature has a great influence on the on-state performances of the tested devices, but that the switching performances of SiC Schottky diodes and COOLMOSTM transistors are not significantly modified at elevated temperatures.

27. ISOCAM mapping of the ρ Ophiuchi main cloud

Author

Abergel, A., Bernard, J. P., Boulanger, F., Cesarsky, C., Désert, F. X., Falgarone, E., Lagache, G., Perault, M., Puget, J. -L, Reach, W. T., Nordh, L., Olofsson, G., Huldtgren, M., Kaas, A. A., André, P., Bontemps, S., Martin Burgdorf, Copet, E., Davies, J., Montmerle, T., Persi, P., and Sibille, F.

28. Origin of the hot gas in low-mass protostars

Author

Kempen, T. A., Kristensen, L. E., Herczeg, G. J., Visser, R., Dishoeck, E. F., Wampfler, S. F., Bruderer, S., Benz, A. O., Doty, S. D., Brinch, C., Hogerheijde, M. R., Jørgensen, J. K., Tafalla, M., Neufeld, D., Bachiller, R., Baudry, A., Benedettini, M., Bergin, E. A., Bjerkeli, P., Blake, G. A., Bontemps, S., Braine, J., Caselli, P., Cernicharo, J., Codella, C., Daniel, F., Di Giorgio, A. M., Dominik, C., Encrenaz, P., Fich, M., Fuente, A., Giannini, T., Goicoechea, J. R., Graauw, T., Helmich, F., Herpin, F., Jacq, T., Johnstone, D., Kaufman, M. J., Larsson, B., Lis, D., Liseau, R., Marseille, M., Mccoey, C., Melnick, G., Brunella Nisini, Olberg, M., Parise, B., Pearson, J. C., Plume, R., Risacher, C., Santiago-García, J., Saraceno, P., Shipman, R., Tak, F., Wyrowski, F., Yildiz, U. A., Ciechanowicz, M., Dubbeldam, L., Glenz, S., Huisman, R., Lin, R. H., Morris, P., Murphy, J. A., and Trappe, N.

29. OCAM observations of the RCrA star formation region

Author

Olofsson, G., Huldtgren, M., Kaas, A. A., Bontemps, S., Nordh, L., Abergel, A., André, P., Boulanger, F., Martin Burgdorf, Casali, M. M., Cesarsky, C. J., Davies, J., Falgarone, E., Montmerle, T., Perault, M., Persi, P., Prusti, T., Puget, J. L., and Sibille, F.

30. Clouds, filaments, and protostars: The Herschel Hi-GAL Milky Way

Author

J. A. Rodón, K. Ganga, M. Pomarès, Friedrich Wyrowski, Mika Juvela, F. Piacentini, Melvin Hoare, William T. Reach, Stefano Pezzuto, A. Roy, Jean-Paul Baluteau, Marc-Antoine Miville-Deschenes, Russell H. Taylor, Pierre Royer, Alessio Traficante, Peter Schilke, D. Paradis, Glenn J. White, Cara Battersby, Alberto Noriega-Crespo, Harriet Parsons, M. Veneziani, Dimitrios Stamatellos, Vincent Minier, Lorenzo Piazzo, Guy S. Stringfellow, Michael G. Burton, L. K. Morgan, Frederic Schuller, F. Faustini, P. Saraceno, S. D. Lord, Jason Glenn, E. Sturm, Michael D. Smith, G. Joncas, A. M. di Giorgio, D. Polychroni, L. Montier, D. J. Marshall, N. Billot, José Cernicharo, F. Boulanger, M. T. Beltrán, Paul Martin, Matthew Joseph Griffin, B. Swinyard, Guilaine Lagache, Serena Viti, Mathieu Compiegne, Derek Ward-Thompson, P. de Bernardis, Frédérique Motte, B. Sibthorpe, Sukanya Chakrabarti, Nicolas Flagey, Christopher M. Brunt, Maggie A. Thompson, Qizhou Zhang, J.-P. Bernard, Annie Zavagno, Jean-François Robitaille, L. Spinoglio, Marc Sauvage, D. Russeil, Paolo Natoli, A. Abergel, Babar Ali, Davide Elia, D. Ikhenaode, Gary A. Fuller, C. Joblin, G. de Gasperis, Eugenio Schisano, Pedro García-Lario, Jin-Zeng Li, Isabelle Ristorcelli, Sergio Molinari, Luca Calzoletti, M. R. Pestalozzi, Nicolas Peretto, Thomas P. Robitaille, Mikako Matsuura, Riccardo Cesaroni, Rene Plume, Jan Brand, Paul F. Goldsmith, Leonardo Testi, Joseph C. Mottram, H. W. Yorke, Cristina Popescu, Martin Cohen, M. Benedettini, M. J. Barlow, Antonio Chrysostomou, Paola Caselli, Luca Olmi, Maohai Huang, Massimo Marengo, R. Paladini, Fabrizio Massi, L. A. Wilcock, Grazia Umana, Francesco Strafella, Toby J. T. Moore, Benjamin L. Schulz, R. Vavrek, T. Mueller, John Bally, J. A. D. L. Blommaert, L. D. Anderson, C. Waelkens, T. L. Lim, Richard J. Tuffs, Sean Carey, Yasuo Fukui, J. Neves, Nicola Schneider, Jason M. Kirk, Silvia Masi, Pascal André, Howard A. Smith, Luca Valenziano, Sylvain Bontemps, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), 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), 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), CITA, University of Toronto, European Southern Observatory (ESO), 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), Laboratory of Comparative Carcinogenesis (LABORATORY OF COMPARATIVE CARCINOGENESIS), National Cancer Institute [Bethesda] (NCI-NIH), National Institutes of Health [Bethesda] (NIH)-National Institutes of Health [Bethesda] (NIH), Laboratoire d'Informatique de Nantes Atlantique (LINA), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), 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), FORMATION STELLAIRE 2010, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), 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), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, APC - Cosmologie, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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), ISO Data Centre (ESA - Espagne), Agence Spatiale Européenne = European Space Agency (ESA), Herschel Science Centre (ESA Espagne), National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Universiti Brunei Darussalam, Biology Department, Universitii Brunei Darussalam, Università degli Studi di Roma Tor Vergata [Roma], University of Manchester [Manchester], 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), Tenovus Centre for Cancer Research, Welsh School of Pharmacy, Antarctic Research a European Network for Astrophysics (ARENA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Inter University Accelerator Centre, Aruna Asaf Ali Marg, LEOSPHERE France, LEOSPHERE, Max-Planck-Institut für Radioastronomie (MPIFR), Laboratoire de Radioastronomie (LRA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Royal Observatory Edinburgh (ROE), University of Edinburgh, Atmospheric Sciences Division [Hampton], NASA Langley Research Center [Hampton] (LaRC), School of Physics and Astronomy [Cardiff], Cardiff University, Shanghai Inst Opt & Fine Mech, Key Lab Mat Sci & Technol High Power Lasers, Molinari, S., Swinyard, B., Bally, J., Barlow, M., Bernard, J. P., Martin, P., Moore, T., Noriega Crespo, A., Plume, R., Testi, L., Zavagno, A., Abergel, A., Ali, B., Anderson, L., Andre, P., Baluteau, J. P., Battersby, C., Beltrán, M. T., Benedettini, M., Billot, N., Blommaert, J., Bontemps, S., Boulanger, F., Brand, J., Brunt, C., Burton, M., Calzoletti, L., Carey, S., Caselli, P., Cesaroni, R., Cernicharo, J., Chakrabarti, S., Chrysostomou, A., Cohen, M., Compiegne, M., de Bernardis, P., de Gasperis, G., di Giorgio, A. M., Elia, Davide Quintino, Faustini, F., Flagey, N., Fukui, Y., Fuller, G. A., Ganga, K., Garcia Lario, P., Glenn, J., Goldsmith, P. F., Griffin, M., Hoare, M., Huang, M., Ikhenaode, D., Joblin, C., Joncas, G., Juvela, M., Kirk, J. M., Lagache, G., Li, J. Z., Lim, T. L., Lord, S. D., Marengo, M., Marshall, D. J., Masi, S., Massi, F., Matsuura, M., Minier, V., Miville Deschênes, M. A., Montier, L. A., Morgan, L., Motte, F., Mottram, J. C., Müller, T. G., Natoli, P., Neves, J., Olmi, L., Paladini, R., Paradis, D., Parsons, H., Peretto, N., Pestalozzi, M., Pezzuto, S., Piacentini, F., Piazzo, L., Polychroni, D., Pomarès, M., Popescu, C. C., Reach, W. T., Ristorcelli, I., Robitaille, J. F., Robitaille, T., Rodón, J. A., Roy, A., Royer, P., Russeil, D., Saraceno, P., Sauvage, M., Schilke, P., Schisano, E., Schneider, N., Schuller, F., Schulz, B., Sibthorpe, B., Smith, H. A., Smith, M. D., Spinoglio, L., Stamatellos, D., Strafella, Francesco, Stringfellow, G. S., Sturm, E., Taylor, R., Thompson, M. A., Traficante, A., Tuffs, R. J., Umana, G., Valenziano, L., Vavrek, R., Veneziani, M., Viti, S., Waelkens, C., Ward Thompson, D., White, G., Wilcock, L. A., Wyrowski, F., Yorke, H. W., Zhang, Q., Consiglio Nazionale delle Ricerche (CNR), 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, 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)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Centre National de la Recherche Scientifique (CNRS)-Mines Nantes (Mines Nantes)-Université de Nantes (UN), 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), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), European Space Agency (ESA), Dipartimento di Fisica, Universita` di Roma Tor Vergata, 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)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), 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), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), 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), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), ITA, USA, GBR, FRA, DEU, and ESP

Subjects
010504 meteorology & atmospheric sciences, Field (physics), Milky Way, stars: formation, ISM: structure, ISM: clouds, Galaxy: general, FOS: Physical sciences, ism: structure, ism: clouds, galaxy: general, Astrophysics, 01 natural sciences, Protein filament, Settore FIS/05 - Astronomia e Astrofisica, 0103 physical sciences, Protostar, Infrared dark cloud, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, Galactic plane, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, Core (optical fiber), Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Magnetohydrodynamics
Abstract

We present the first results from the science demonstration phase for the Hi-GAL survey, the Herschel key-project that will map the inner Galactic Plane of the Milky Way in 5 bands. We outline our data reduction strategy and present some science highlights on the two observed 2{\deg} x 2{\deg} tiles approximately centered at l=30{\deg} and l=59{\deg}. The two regions are extremely rich in intense and highly structured extended emission which shows a widespread organization in filaments. Source SEDs can be built for hundreds of objects in the two fields, and physical parameters can be extracted, for a good fraction of them where the distance could be estimated. The compact sources (which we will call 'cores' in the following) are found for the most part to be associated with the filaments, and the relationship to the local beam-averaged column density of the filament itself shows that a core seems to appear when a threshold around A_V of about 1 is exceeded for the regions in the l=59{\deg} field; a A_V value between 5 and 10 is found for the l=30{\deg} field, likely due to the relatively larger distances of the sources. This outlines an exciting scenario where diffuse clouds first collapse into filaments, which later fragment to cores where the column density has reached a critical level. In spite of core L/M ratios being well in excess of a few for many sources, we find core surface densities between 0.03 and 0.5 g cm-2. Our results are in good agreement with recent MHD numerical simulations of filaments forming from large-scale converging flows., Comment: A&A, accepted

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