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30 results on '"B. Nisini"'

1. Gaia23bab: A New EXor

Author

T. Giannini, E. Schisano, B. Nisini, P. Ábrahám, S. Antoniucci, K. Biazzo, F. Cruz-Sáenz de Miera, E. Fiorellino, M. Gangi, A. Kóspál, M. Kuhn, E. Marini, Z. Nagy, and D. Paris

Subjects
Eruptive variable stars, Stellar accretion, Pre-main sequence stars, Star formation, Astrophysics, QB460-466
Abstract

On 2023 March 6, the Gaia telescope alerted a 2 mag burst from Gaia23bab, a young stellar object in the Galactic plane. We observed Gaia23bab with the Large Binocular Telescope obtaining optical and near-infrared spectra close in time to the peak of the burst, and collected all public multiband photometry to reconstruct the historical light curve. The latter shows three bursts in 10 years (2013, 2017, and 2023), whose duration and amplitude are typical of EXor variables. We estimate that, due to the bursts, the mass accumulated on the star is about twice greater than if the source had remained quiescent for the same period of time. Photometric analysis indicates that Gaia23bab is a class II source with age ≲1 Myr, spectral type G3−K0, stellar luminosity ∼4.0 L _⊙ , and mass ∼1.6 M _⊙ . The optical/near-infrared spectrum is rich in emission lines. From the analysis of these lines we measured an accretion luminosity and mass accretion rate ( L _acc ^burst ∼ 3.7 L _⊙ , ${\dot{M}}_{\mathrm{acc}}$ ^burst ∼ 2.0 × 10 ^−7 M _⊙ yr ^−1 ) consistent with those of EXors. More generally, we derived the relationships between accretion and stellar parameters in a sample of EXors. We find that, when in burst, the accretion parameters become almost independent of the stellar parameters and that EXors, even in quiescence, are more efficient than classical T Tauri stars in assembling mass.

Published
2024
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2. Accretion and outflows in young stars with CUBES

Author

J. M. Alcalá, G. Cupani, C. J. Evans, M. Franchini, and B. Nisini

Subjects
Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The science case on studies of accretion and outflows in low-mass ($$M_{\odot }$$ M ⊙ ) young stellar objects (YSOs) with the new CUBES instrument is presented. We show the need for a high-sensitivity, near-ultraviolet (NUV) spectrograph like CUBES, with a resolving power at least four times that of X-Shooter and combined with UVES via a fibrelink for simultaneous observations. Simulations with the CUBES exposure time calculator and the end-to-end software show that a significant gain in signal-to-noise can be achieved compared to current instruments, for both the spectral continuum and emission lines, including for relatively embedded YSOs. Our simulations also show that the low-resolution mode of CUBES will be able to observe much fainter YSOs (V $$\sim$$ ∼ 22 mag) in the NUV than we can today, allowing us extend studies to YSOs with background-limited magnitudes. The performance of CUBES in terms of sensitivity in the NUV will provide important new insights into the evolution of circumstellar disks, by studying the accretion, jets/winds and photo-evaporation processes, down to the low-mass brown dwarf regime. CUBES will also open-up new science as it will be able to observe targets that are several magnitudes fainter than those reachable with current instruments, facilitating studies of YSOs at distances of $$\sim$$ ∼ kpc scale. This means a step-change in the field of low-mass star formation, as it will be possible to expand the science case from relatively local star-forming regions to a large swathe of distances within the Milky Way.

Published
2022
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3. EXORCISM: a spectroscopic survey of young eruptive variables (EXor and candidates)

Author

T. Giannini, A. Giunta, M. Gangi, R. Carini, D. Lorenzetti, S. Antoniucci, A. Caratti o Garatti, L. Cassará, B. Nisini, A. Rossi, V. Testa, and F. Vitali

Subjects
Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

We present an optical/near-IR survey of 11 variable young stars (EXors and EXor candidates) aimed at deriving and monitoring their accretion properties. About 30 optical and near-infrared spectra ($\Re$ $\sim$ 1500-2000) were collected between 2014-2019 with the Large Binocular Telescope (LBT). From the spectral analysis we have derived the accretion luminosity and mass accretion rate, the visual extinction, the temperature and density of the permitted line formation region, and the signature of the outflowing matter. Two sources (ASASSN-13db and iPTF15afq) have been observed in outburst and quiescence, three during a high-level of brightness (XZ Tau, PV Cep, and NY Ori), and the others in quiescence. These latter have accretion luminosity and mass accretion rates in line with the values measured in classical T Tauri stars of similar mass. All sources observed more than once present accretion variability. The most extreme case is ASASSN-13db, for which the mass accretion rate decreases by two orders of magnitude from the outburst peak in 2015 to quiescence in 2017. Also, in NY Ori the accretion luminosity decreases by a factor 25 in one year. In 80% of the sample we detect the [OI]630 nm line, a tracer of mass loss. From the variability of the H$\alpha$/[OI]630, ratio, we conclude that mass accretion variations are larger than mass loss variations. From the analysis of the HI recombination lines a correlation is suggested between the density of the line formation region and the level of accretion activity of the source., Comment: To appear in ApJ

Published
2022

4. GIARPS High-resolution Observations of T Tauri stars (GHOsT). IV. Accretion properties of the Taurus-Auriga young association

Author

M. Gangi, S. Antoniucci, K. Biazzo, A. Frasca, B. Nisini, J. M. Alcalá, T. Giannini, C. F. Manara, A. Giunta, A. Harutyunyan, U. Munari, and F. Vitali

Subjects
Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

In the framework of the GIARPS@TNG High-resolution Observations of T Tauri stars (GHOsT) project, we study the accretion properties of 37 Classical T Tauri Stars of the Taurus-Auriga star forming region (SFR) with the aim of characterizing their relation with the properties of the central star, of jets and disk winds, and of the global disk structure, in synergy with complementary ALMA millimiter observations. We derive stellar parameters, optical veiling, accretion luminosity ($\rm L_{acc}$) and mass accretion rate ($\rm \dot M_{acc}$) in a homogeneous and self-consistent way using high-resolution spectra acquired at the Telescopio Nazionale Galileo with the HARPS-N and GIANO spectrographs, and flux-calibrated based on contemporaneous low-resolution spectroscopic and photometric ancillary observations. The $\rm L_{acc}$-$\rm L_{\star}$, $\rm \dot{M}_{acc}$-$\rm M_{\star}$ and $\rm \dot{M}_{acc}$-$\rm M_{disk}$ relationships of the Taurus sample are provided and compared with those of the coeval SFRs of Lupus and Chamaeleon I. Our results demonstrate the potential of contemporaneous optical and near-infrared high-resolution spectroscopy to simultaneously provide precise measurements of stellar and accretion/wind properties of young stars., Comment: 30 pages, 18 figures, 6 tables. Accepted for publication on Astronomy and Astrophysics

Published
2022
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5. The He I λ10830 Å line as a probe of winds and accretion in young stars in Lupus and Upper Scorpius

Author

J. Erkal, C. F. Manara, P. C. Schneider, M. Vincenzi, B. Nisini, D. Coffey, J. M. Alcalá, D. Fedele, and S. Antoniucci

Subjects
Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

The He I 1 micron line is a high excitation line which allows us to probe the innermost regions of protostellar disks, and to trace both accreting and outflowing material. We use X-Shooter observations of a sample of 107 young stars in the Lupus (1-3 Myr) and Upper Scorpius (5-10 Myr) star-forming regions to search for correlations between the line properties, as well as the disk inclination and accretion luminosity. We identified eight distinct profile types in the sample. We fitted Gaussian curves to the line features to measure the maximum velocities traced in absorption, the full-width half-maximum (FWHM) of the line features, and the Gaussian area of the features. We compare the proportion of each profile type in our sample to previous studies in Taurus. We find significant variations between Taurus and Lupus in the proportion of P Cygni and inverse P Cygni profiles, and between Lupus and Upper Scorpius in the number of emission-only and combination profile types. We find that the blue-shifted absorption features appear less blue-shifted at disk inclinations close to edge-on, but no such trend with inclination is observed in sources with only red-shifted features. Higher accretion rates were observed in sources with strong blue-shifted features which, along with the changes in the proportions of each profile type observed in the two regions, indicates that younger sources may drive stronger jets or winds. Overall, we observe variations in the proportion of each profile type and in the line properties which indicates and evolution of accretion and ejection signatures over time, and with source properties. These results confirm past works and models of the He I line, but for a larger sample and for multiple star-forming regions. The work highlights the power of the He I line as a probe of the gas in the innermost regions of the disk., Comment: 24 pages, 21 figures, 4 tables - accepted by A&A on 01/08/2022

Published
2022
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6. ELT-HIRES, the high resolution spectrograph for the ELT: the Phase A study and the path to construction

Author

François Bouchy, Andrzej Niedzielski, Thomas Marquart, Stefano Cristiani, Giuseppina Micela, Matteo Genoni, Livia Origlia, Eric Stempels, Philipp Huke, A. Fragoso, I. de Castro Leão, G. Pietrzynski, Valentina D'Odorico, Erik Zackrisson, C. Hansen, E. Niemczura, Graham J. Murray, D. Sosnowska, Andreas Korn, Edwin A. Bergin, Michella Grey Araújo Monteiro, A. Cabral, A. Humphrey, M. R. Zapatero Osorio, P. Figueira, Stefano Covino, Sheila Vilarindo de Sousa, E. Gallo, John D. Monnier, Matteo Aliverti, Igor Coretti, Jose Luis Rasilla, G. Cupani, Sergio Ribeiro Augusto, David Lunney, José Peñate, Luca Pasquini, Lise Christensen, Klaus G. Strassmeier, Phil Rees, Andrea Chiavassa, Marco Riva, C. Lovis, Alessandro Marconi, B. L. Canto Martins, Étienne Artigau, B. Chazelas, Vardan Adibekyan, Enrico Pinna, Nelson J. Nunes, Christoph Mordasini, F. Sortino, Raffaele Gratton, Enric Palle, Rafael Rebolo, Lison Malo, Holger Drass, Isabelle Boisse, Tzu-Chiang Shen, P. Maslowski, I. Hughes, F. Tenegi, P. Parr-Burman, Hans Kjeldsen, René Doyon, A. Mucciarelli, Pedro J. Amado, J. I. González Hernández, Björn Benneke, Andrea Tozzi, Elena Mason, Johan P. U. Fynbo, Roberto Maiolino, M. Woche, C. Allende Prieto, Nikolai Piskunov, M. Amate, D. Romano, Nicoletta Sanna, J. R. De Medeiros, Tim Morris, P. Di Marcantonio, M. Sarajlic, A. Pollo, Xavier Bonfils, R. Calvo-Ortega, Francesco Pepe, Marco Xompero, Paolo Molaro, Roberto Cirami, Philippe Berio, G. Cresci, N. Bezawada, B. Nisini, L. Vanzi, J. Hlavacek-Larrondo, Ansgar Reiners, Ernesto Oliva, Manuel Abreu, M. A. F. de Souza, Stéphane Udry, Martin G. Haehnelt, Luca Valenziano, Michael Weber, S. Becerril, S. Rousseau, Cristina Martins, C. Broeg, Marco Landoni, S. C. C. Barros, V. Cunha Parro, Jochen Liske, I. Di Varano, Driss Kouach, Giorgio Pariani, ITA, USA, GBR, FRA, DEU, ESP, BRA, CAN, CHL, DNK, POL, SWE, CHE, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, COSMIC cancer database, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Phase (waves), Astronomy, 01 natural sciences, Exoplanet, 010309 optics, Stars, 0103 physical sciences, Path (graph theory), Spectral resolution, Extremely large telescope, 010303 astronomy & astrophysics, Spectrograph, ComputingMilieux_MISCELLANEOUS
Abstract

HIRES is the high-resolution spectrograph of the European Extremely Large Telescope at optical and near-infrared wavelengths. It consists of three fibre-fed spectrographs providing a wavelength coverage of 0.4-1.8 µm (goal 0.35-2.4 µm) at a spectral resolution of 100,000. The fibre-feeding allows HIRES to have several, interchangeable observing modes including a SCAO module and a small diffraction-limited IFU in the NIR. Therefore, it will be able to operate both in seeing- and diffraction-limited modes. Its modularity will ensure that HIRES can be placed entirely on the Nasmyth platform, if enough mass and volume is available, or part on the Nasmyth and part in the Coud`e room. ELT-HIRES has a wide range of science cases spanning nearly all areas of research in astrophysics and even fundamental physics. Among the top science cases there are the detection of biosignatures from exoplanet atmospheres, finding the fingerprints of the first generation of stars (PopIII), tests on the stability of Nature’s fundamental couplings, and the direct detection of the cosmic acceleration. The HIRES consortium is composed of more than 30 institutes from 14 countries, forming a team of more than 200 scientists and engineers.

Published
2020
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8. Far-IR Spectrophotometry of HH Flows with the ISO Long-Wavelength Spectrometer

Author

R. Liseau, T. Giannini, B. Nisini, P. Saraceno, L. Spinoglio, B. Larsson, D. Lorenzetti, and E. Tommasi

Abstract

Full Iso-Lws spectral scans between about 45 to 190 μm of 17 individual HH objects in 7 star forming regions have revealed essentially only [O I] 63 μm line emission, implying that the Fircooling of these objects is totally dominated by this line alone. In this case, J-shock models can be used to determine the mass loss rates of the HH exciting sources. These mass loss rates are in reasonably good agreement with those estimated for the accompanying CO flows, providing first observational evidence that HH and molecular flows are driven by the same agent. The Lmech – Lbol relation, based on our results with the Lws, implies that young stellar objects of lower mass are loosing mass at relatively higher rates than their more massive counterparts.

Published
1997
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9. Herschel/HIFI discovery of interstellar chloronium (H2Cl+)

Author

D. C. Lis, J. C. Pearson, D. A. Neufeld, P. Schilke, H. S. P. Müller, H. Gupta, T. A. Bell, C. Comito, T. G. Phillips, E. A. Bergin, C. Ceccarelli, P. F. Goldsmith, G. A. Blake, A. Bacmann, A. Baudry, M. Benedettini, A. Benz, J. Black, A. Boogert, S. Bottinelli, S. Cabrit, P. Caselli, A. Castets, E. Caux, J. Cernicharo, C. Codella, A. Coutens, N. Crimier, N. R. Crockett, F. Daniel, K. Demyk, C. Dominic, M.-L. Dubernet, M. Emprechtinger, P. Encrenaz, E. Falgarone, A. Fuente, M. Gerin, T. F. Giesen, J. R. Goicoechea, F. Helmich, P. Hennebelle, Th. Henning, E. Herbst, P. Hily-Blant, Å. Hjalmarson, D. Hollenbach, T. Jack, C. Joblin, D. Johnstone, C. Kahane, M. Kama, M. Kaufman, A. Klotz, W. D. Langer, B. Larsson, J. Le Bourlot, B. Lefloch, F. Le Petit, D. Li, R. Liseau, S. D. Lord, A. Lorenzani, S. Maret, P. G. Martin, G. J. Melnick, K. M. Menten, P. Morris, J. A. Murphy, Z. Nagy, B. Nisini, V. Ossenkopf, S. Pacheco, L. Pagani, B. Parise, M. Pérault, R. Plume, S.-L. Qin, E. Roueff, M. Salez, A. Sandqvist, P. Saraceno, S. Schlemmer, K. Schuster, R. Snell, J. Stutzki, A. Tielens, N. Trappe, F. F. S. van der Tak, M. H. D. van der Wiel, E. van Dishoeck, C. Vastel, S. Viti, V. Wakelam, A. Walters, S. Wang, F. Wyrowski, H. W. Yorke, S. Yu, J. Zmuidzinas, Y. Delorme, J.-P. Desbat, R. Güsten, J.-M. Krieg, B. Delforge, California Institute of Technology (CALTECH), foreign laboratories (FL), CERN [Genève], I. Physikalisches Institut [Köln], Universität zu Köln = University of Cologne, Max Planck Institute for Radio Astronomy, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Astronomy [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, 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), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-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), Indiana University Cyclotron Facility (IUCF), Indiana University [Bloomington], Indiana University System-Indiana University System, 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), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), CNRS INSU, UMR 5187, F-31028 Toulouse 4, France, UMR 5187 Toulouse, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Université Paris sciences et lettres (PSL), Cahill Center for Astronomy and Astrophysics, Laboratoire de Radioastronomie (LRA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), 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), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Ohio State Univ, Dept Phys, Columbus, OH 43210 USA, Ohio State University [Columbus] (OSU), Ohio State Univ, Dept Astron & Chem, Columbus, OH 43210 USA, Onsala Space Observatory, Chalmers University of Technology [Göteborg], Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7 Canada, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Modélisation Multi-échelles des Combustibles (LM2C), Service d'Etudes de Simulation du Comportement du combustibles (SESC), Département d'Etudes des Combustibles (DEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Département d'Etudes des Combustibles (DEC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, Max-Planck-Institut für Radioastronomie (MPIFR), Infrared Processing and Analysis Center (IPAC), Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Roma (OAR), 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)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), Department of Physics and Astronomy [Calgary], University of Calgary, Stockholm Observatory Department of Astronomy, Stockholm University, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Laboratoire de Didactique André Revuz (LDAR (EA_4434)), Université d'Artois (UA)-Université Paris Diderot - Paris 7 (UPD7)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Leiden Observatory [Leiden], Universiteit Leiden, AMOR 2010, Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, Univ Cologne, Inst Phys 1, 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 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), 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, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Univ Toulouse UPS, Ctr Etud Spatiale Rayonnements, F-31062 Toulouse 9, France, Centre Etud Spatiale Rayonnements Toulouse, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid 28850, Spain, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid, École normale supérieure - Paris (ENS Paris), 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), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction de l'Energie Nucléaire (CEA-DEN), Harvard University [Cambridge]-Smithsonian Institution, CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA, CALTECH, Ctr Infrared Proc & Anal, Pasadena, Osservatorio di Astrofisica di Roma (OAR), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Consiglio Nazionale delle Ricerche (CNR), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université Paris Diderot - Paris 7 (UPD7)-Université d'Artois (UA), Universiteit Leiden [Leiden], Astronomy, Kapteyn Astronomical Institute, Universität zu Köln, 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)-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), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Institut National Polytechnique de Grenoble (INPG), Smithsonian Institution-Harvard University [Cambridge], 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), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Faure, Alexandre, Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Experimental Physics, STAR-FORMING REGION, CHLORINE-BEARING MOLECULES, FOS: Physical sciences, Astrophysics, 01 natural sciences, COLOGNE DATABASE, ISM: abundances, 0103 physical sciences, Absorption (logic), HYDROGEN-CHLORIDE, 010306 general physics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, NGC 6334 I, Physics, SPECTROSCOPY, astrochemistry, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Space observatory, ISM: molecules, SPIRAL ARM CLOUDS, Interstellar medium, submillimetre: ISM, molecular processes, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), GROUND-STATE, ISOTOPIC RATIO, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], SUBMILLIMETER, line: identification
Abstract

We report the first detection of chloronium, H$_2$Cl$^+$, in the interstellar medium, using the HIFI instrument aboard the \emph{Herschel} Space Observatory. The $2_{12}-1_{01}$ lines of ortho-H$_2^{35}$Cl$^+$ and ortho-H$_2^{37}$Cl$^+$ are detected in absorption towards NGC~6334I, and the $1_{11}-0_{00}$ transition of para-H$_2^{35}$Cl$^+$ is detected in absorption towards NGC~6334I and Sgr~B2(S). The H$_2$Cl$^+$ column densities are compared to those of the chemically-related species HCl. The derived HCl/H$_2$Cl$^+$ column density ratios, $\sim$1--10, are within the range predicted by models of diffuse and dense Photon Dominated Regions (PDRs). However, the observed H$_2$Cl$^+$ column densities, in excess of $10^{13}$~cm$^{-2}$, are significantly higher than the model predictions. Our observations demonstrate the outstanding spectroscopic capabilities of HIFI for detecting new interstellar molecules and providing key constraints for astrochemical models., Comment: Accepted for publication in A&A, HIFI Special Issue; 4 pages, 2 figures, 1 table

Published
2010
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10. Herschel/HIFI spectroscopy of the intermediate mass protostar NGC7129 FIRS 2 [Letter]

Author

D. Johnstone, M. Fich, C. McCoey, T. A. van Kempen, A. Fuente, L. E. Kristensen, J. Cernicharo, P. Caselli, R. Visser, R. Plume, G. J. Herczeg, E. F. van Dishoeck, S. Wampfler, R. Bachiller, A. Baudry, M. Benedettini, E. Bergin, A. O. Benz, P. Bjerkeli, G. Blake, S. Bontemps, J. Braine, S. Bruderer, C. Codella, F. Daniel, A. M. di Giorgio, C. Dominik, S. D. Doty, P. Encrenaz, T. Giannini, J. R. Goicoechea, Th. de Graauw, F. Helmich, F. Herpin, M. R. Hogerheijde, T. Jacq, J. K. Jørgensen, B. Larsson, D. Lis, R. Liseau, M. Marseille, G. Melnick, D. Neufeld, B. Nisini, M. Olberg, B. Parise, J. Pearson, C. Risacher, J. Santiago-García, P. Saraceno, R. Shipman, M. Tafalla, F. van der Tak, F. Wyrowski, U. A. Yıldız, E. Caux, N. Honingh, W. Jellema, R. Schieder, D. Teyssier, N. Whyborn, 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), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), 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 (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 Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], 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), ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), Herschel Science Center [Madrid], European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Astronomy, 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, École normale supérieure - Paris (ENS Paris), 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), European Space Agency (ESA)-European Space Agency (ESA), and Low Energy Astrophysics (API, FNWI)

Subjects
STAR-FORMING REGIONS, stars: formation, PACS SPECTROSCOPY, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], astrochemistry, FOS: Physical sciences, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], YOUNG STELLAR OBJECTS, 01 natural sciences, EVOLUTION, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, EXCITATION, WATER, 010306 general physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), HIFI, HH 46, QB
Abstract

HERSCHEL-HIFI observations of water from the intermediate mass protostar NGC7129 FIRS 2 provide a powerful diagnostic of the physical conditions in this star formation environment. Six spectral settings, covering four H216O and two H218O lines, were observed and all but one H218O line were detected. The four H2 16 O lines discussed here share a similar morphology: a narrower, \approx 6 km/s, component centered slightly redward of the systemic velocity of NGC7129 FIRS 2 and a much broader, \approx 25 km/s component centered blueward and likely associated with powerful outflows. The narrower components are consistent with emission from water arising in the envelope around the intermediate mass protostar, and the abundance of H2O is constrained to \approx 10-7 for the outer envelope. Additionally, the presence of a narrow self-absorption component for the lowest energy lines is likely due to self-absorption from colder water in the outer envelope. The broader component, where the H2O/CO relative abundance is found to be \approx 0.2, appears to be tracing the same energetic region that produces strong CO emission at high J., 6 pages, 4 figures, accepted by A&A

Published
2010
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11. Water in massive star-forming regions: HIFI observations of W3 IRS5

Author

L. Chavarría, F. Herpin, T. Jacq, J. Braine, S. Bontemps, A. Baudry, M. Marseille, F. van der Tak, B. Pietropaoli, F. Wyrowski, R. Shipman, W. Frieswijk, E. F. van Dishoeck, J. Cernicharo, R. Bachiller, M. Benedettini, A. O. Benz, E. Bergin, P. Bjerkeli, G. A. Blake, S. Bruderer, P. Caselli, C. Codella, F. Daniel, A. M. di Giorgio, C. Dominik, S. D. Doty, P. Encrenaz, M. Fich, A. Fuente, T. Giannini, J. R. Goicoechea, Th. de Graauw, P. Hartogh, F. Helmich, G. J. Herczeg, M. R. Hogerheijde, D. Johnstone, J. K. Jørgensen, L. E. Kristensen, B. Larsson, D. Lis, R. Liseau, C. McCoey, G. Melnick, B. Nisini, M. Olberg, B. Parise, J. C. Pearson, R. Plume, C. Risacher, J. Santiago-García, P. Saraceno, J. Stutzki, R. Szczerba, M. Tafalla, A. Tielens, T. A. van Kempen, R. Visser, S. F. Wampfler, J. Willem, U. A. Yıldız, Astronomy, Low Energy Astrophysics (API, FNWI), 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), SRON Netherlands Institute for Space Research (SRON), 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), Max-Planck-Institut für Radioastronomie (MPIFR), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], 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, ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), 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), École normale supérieure - Paris (ENS-PSL), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), 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), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
010504 meteorology & atmospheric sciences, TRACERS, Astronomy, MODELS, FOS: Physical sciences, Astrophysics, 01 natural sciences, Spectral line, ISM: abundances, ABUNDANCES, RADIATIVE-TRANSFER, Abundance (ecology), 0103 physical sciences, Radiative transfer, Isotopologue, Spectral resolution, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), QB, 0105 earth and related environmental sciences, Envelope (waves), Physics, radio lines: ISM, TRAPEZIUM, stars: formation, SPECTROSCOPY, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, extinction, PROTOSTARS, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], ISM: molecules, RATIOS, stars: massive, ENVELOPES, CONTINUUM, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Outflow, dust, dust, extinction
Abstract

We present Herschel observations of the water molecule in the massive star-forming region W3 IRS5. The o-H17O 110-101, p-H18O 111-000, p-H2O 22 202-111, p-H2O 111-000, o-H2O 221-212, and o-H2O 212-101 lines, covering a frequency range from 552 up to 1669 GHz, have been detected at high spectral resolution with HIFI. The water lines in W3 IRS5 show well-defined high-velocity wings that indicate a clear contribution by outflows. Moreover, the systematically blue-shifted absorption in the H2O lines suggests expansion, presumably driven by the outflow. No infall signatures are detected. The p-H2O 111-000 and o-H2O 212-101 lines show absorption from the cold material (T ~ 10 K) in which the high-mass protostellar envelope is embedded. One-dimensional radiative transfer models are used to estimate water abundances and to further study the kinematics of the region. We show that the emission in the rare isotopologues comes directly from the inner parts of the envelope (T > 100 K) where water ices in the dust mantles evaporate and the gas-phase abundance increases. The resulting jump in the water abundance (with a constant inner abundance of 10^{-4}) is needed to reproduce the o-H17O 110-101 and p-H18O 111-000 spectra in our models. We estimate water abundances of 10^{-8} to 10^{-9} in the outer parts of the envelope (T < 100 K). The possibility of two protostellar objects contributing to the emission is discussed., Accepted for publication in the A&A HIFI special issue

Published
2010
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12. Water abundance variations around high-mass protostars: HIFI observations of the DR21 region

Author

F. F. S. van der Tak, M. G. Marseille, F. Herpin, F. Wyrowski, A. Baudry, S. Bontemps, J. Braine, S. Doty, W. Frieswijk, G. Melnick, R. Shipman, E. F. van Dishoeck, A. O. Benz, P. Caselli, M. Hogerheijde, D. Johnstone, R. Liseau, R. Bachiller, M. Benedettini, E. Bergin, P. Bjerkeli, G. Blake, S. Bruderer, J. Cernicharo, C. Codella, F. Daniel, A. M. di Giorgio, C. Dominik, P. Encrenaz, M. Fich, A. Fuente, T. Giannini, J. Goicoechea, Th. de Graauw, F. Helmich, G. Herczeg, J. Jørgensen, L. Kristensen, B. Larsson, D. Lis, C. McCoey, D. Neufeld, B. Nisini, M. Olberg, B. Parise, J. Pearson, R. Plume, C. Risacher, J. Santiago, P. Saraceno, M. Tafalla, T. van Kempen, R. Visser, S. Wampfler, U. Yıldız, L. Ravera, P. Roelfsema, O. Siebertz, D. Teyssier, Low Energy Astrophysics (API, FNWI), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], 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), 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, SRON Netherlands Institute for Space Research (SRON), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Max-Planck-Institut für Radioastronomie (MPIFR), and Astronomy

Subjects
010504 meteorology & atmospheric sciences, LINE EMISSION, Continuum (design consultancy), FOS: Physical sciences, CYGNUS-X, Astrophysics, 01 natural sciences, Spectral line, STAR-FORMATION, RADIATIVE-TRANSFER, ISM: individual objects: DR21, YOUNG STARS, EXCITATION, 0103 physical sciences, ABSORPTION, Radiative transfer, Protostar, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, QB, 0105 earth and related environmental sciences, Line (formation), H-2, Physics, stars: formation, astrochemistry, Star formation, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], MONTE-CARLO METHOD, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, ISM: molecules, EVOLUTION, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Outflow, Galaxy Astrophysics
Abstract

Water is a key molecule in the star formation process, but its spatial distribution in star-forming regions is not well known. We study the distribution of dust continuum and H2O and 13CO line emission in DR21, a luminous star-forming region with a powerful outflow and a compact HII region. Herschel-HIFI spectra near 1100 GHz show narrow 13CO 10-9 emission and H2O 1(11)-0(00) absorption from the dense core and broad emission from the outflow in both lines. The H2O line also shows absorption by a foreground cloud known from ground-based observations of low-J CO lines. The dust continuum emission is extended over 36" FWHM, while the 13CO and H2O lines are confined to ~24" or less. The foreground absorption appears to peak further North than the other components. Radiative transfer models indicate very low abundances of ~2e-10 for H2O and ~8e-7 for 13CO in the dense core, and higher H2O abundances of ~4e-9 in the foreground cloud and ~7e-7 in the outflow. The high H2O abundance in the warm outflow is probably due to the evaporation of water-rich icy grain mantles, while the H2O abundance is kept down by freeze-out in the dense core and by photodissociation in the foreground cloud., Comment: Accepted by A&A Letters (Herschel special issue); 4 pages, 4 figures

Published
2010
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13. The methanol lines and hot core of OMC2-FIR4, an intermediate-mass protostar, with Herschel-HIFI

Author

M. Kama, C. Dominik, S. Maret, F. van der Tak, E. Caux, C. Ceccarelli, A. Fuente, N. Crimier, S. Lord, A. Bacmann, A. Baudry, T. Bell, M. Benedettini, E. A. Bergin, G. A. Blake, A. Boogert, S. Bottinelli, S. Cabrit, P. Caselli, A. Castets, J. Cernicharo, C. Codella, C. Comito, A. Coutens, K. Demyk, P. Encrenaz, E. Falgarone, M. Gerin, P. F. Goldsmith, F. Helmich, P. Hennebelle, T. Henning, E. Herbst, P. Hily-Blant, T. Jacq, C. Kahane, A. Klotz, W. Langer, B. Lefloch, D. Lis, A. Lorenzani, G. Melnick, B. Nisini, S. Pacheco, L. Pagani, B. Parise, J. Pearson, T. Phillips, M. Salez, P. Saraceno, P. Schilke, K. Schuster, X. Tielens, M. H. D. van der Wiel, C. Vastel, S. Viti, V. Wakelam, A. Walters, F. Wyrowski, H. Yorke, P. Cais, R. Güsten, S. Philipp, T. Klein, 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), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), 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), 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), Civilisations atlantiques & Archéosciences (C2A), Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR Histoire, Histoire de l'Art et Archéologie (UFR HHAA), Université de Nantes (UN)-Université de Nantes (UN), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-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, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Radioastronomie (LRA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), 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), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Ohio State University [Columbus] (OSU), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Osservatorio di Astrofisica di Roma (OAR), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), SRON Netherlands Institute for Space Research (SRON), 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 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), Harvard University-Smithsonian Institution, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), 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), INAF - Osservatorio Astronomico di Roma (OAR), National Research Council of Italy | 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 de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ministère de la Culture et de la Communication (MCC)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR Histoire, Histoire de l'Art et Archéologie (UFR HHAA), École normale supérieure - Paris (ENS Paris), 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), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Astronomy, Low Energy Astrophysics (API, FNWI), Université de Nantes - UFR Histoire, Histoire de l'Art et Archéologie (UFR HHAA), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture et de la Communication (MCC), and Smithsonian Institution-Harvard University [Cambridge]

Subjects
010504 meteorology & atmospheric sciences, Astronomy, Population, FOS: Physical sciences, Astrophysics, 01 natural sciences, ISM: abundances, EXPLANATION, chemistry.chemical_compound, MOLECULES, INTERSTELLAR CLOUDS, 0103 physical sciences, Protostar, education, 010303 astronomy & astrophysics, DIAGNOSTIC-TOOL, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Line (formation), Envelope (waves), QB, Physics, ISM: kinematics and dynamics, STAR-FORMING REGIONS, Range (particle radiation), education.field_of_study, stars: formation, PACS SPECTROSCOPY, Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, Star formation, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, ISM: molecules, Core (optical fiber), ENVELOPES, chemistry, Space and Planetary Science, GAS, Astrophysics of Galaxies (astro-ph.GA), ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, ABUNDANCE, Methanol, EMISSION, Galaxy Astrophysics
Abstract

In contrast with numerous studies on the physical and chemical structure of low- and high-mass protostars, much less is known about their intermediate-mass counterparts, a class of objects that could help to elucidate the mechanisms of star formation on both ends of the mass range. We present the first results from a rich HIFI spectral dataset on an intermediate-mass protostar, OMC2-FIR4, obtained in the CHESS (Chemical HErschel SurveyS of star forming regions) key programme. The more than 100 methanol lines detected between 554 and 961 GHz cover a range in upper level energy of 40 to 540 K. Our physical interpretation focusses on the hot core, but likely the cold envelope and shocked regions also play a role in reality, because an analysis of the line profiles suggests the presence of multiple emission components. An upper limit of 10^-6 is placed on the methanol abundance in the hot core, using a population diagram, large-scale source model and other considerations. This value is consistent with abundances previously seen in low-mass hot cores. Furthermore, the highest energy lines at the highest frequencies display asymmetric profiles, which may arise from infall around the hot core., Comment: 2 figures, accepted for publication in the A&A Herschel-HIFI special issue

Published
2010
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14. Water abundances in high-mass protostellar envelopes: Herschel observations with HIFI

Author

M. G. Marseille, F. F. S. van der Tak, F. Herpin, F. Wyrowski, L. Chavarría, B. Pietropaoli, A. Baudry, S. Bontemps, J. Cernicharo, T. Jacq, W. Frieswijk, R. Shipman, E. F. van Dishoeck, R. Bachiller, M. Benedettini, A. O. Benz, E. Bergin, P. Bjerkeli, G. A. Blake, J. Braine, S. Bruderer, P. Caselli, E. Caux, C. Codella, F. Daniel, P. Dieleman, A. M. di Giorgio, C. Dominik, S. D. Doty, P. Encrenaz, M. Fich, A. Fuente, T. Gaier, T. Giannini, J. R. Goicoechea, Th. de Graauw, F. Helmich, G. J. Herczeg, M. R. Hogerheijde, B. Jackson, H. Javadi, W. Jellema, D. Johnstone, J. K. Jørgensen, D. Kester, L. E. Kristensen, B. Larsson, W. Laauwen, D. Lis, R. Liseau, W. Luinge, C. McCoey, A. Megej, G. Melnick, D. Neufeld, B. Nisini, M. Olberg, B. Parise, J. C. Pearson, R. Plume, C. Risacher, P. Roelfsema, J. Santiago-García, P. Saraceno, P. Siegel, J. Stutzki, M. Tafalla, T. A. van Kempen, R. Visser, S. F. Wampfler, U. A. Yıldız, Low Energy Astrophysics (API, FNWI), 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, SRON Netherlands Institute for Space Research (SRON), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Max-Planck-Institut für Radioastronomie (MPIFR), and Astronomy

Subjects
010504 meteorology & atmospheric sciences, Astronomy, FOS: Physical sciences, Astrophysics, 01 natural sciences, ISM: abundances, STAR-FORMATION, REGION, RADIATIVE-TRANSFER, Abundance (ecology), EXCITATION, 0103 physical sciences, Radiative transfer, H2O, Protostar, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, QB, 0105 earth and related environmental sciences, Envelope (waves), Line (formation), Physics, Line-of-sight, extinction, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Star formation, Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, MONTE-CARLO METHOD, PROTOSTARS, CORES, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, ISM: molecules, EVOLUTION, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, dust, extinction, dust, EMISSION, Galaxy Astrophysics
Abstract

We derive the dense core structure and the water abundance in four massive star-forming regions which may help understand the earliest stages of massive star formation. We present Herschel-HIFI observations of the para-H2O 1_11-0_00 and 2_02-1_11 and the para-H2-18O 1_11-0_00 transitions. The envelope contribution to the line profiles is separated from contributions by outflows and foreground clouds. The envelope contribution is modelled using Monte-Carlo radiative transfer codes for dust and molecular lines (MC3D and RATRAN), with the water abundance and the turbulent velocity width as free parameters. While the outflows are mostly seen in emission in high-J lines, envelopes are seen in absorption in ground-state lines, which are almost saturated. The derived water abundances range from 5E-10 to 4E-8 in the outer envelopes. We detect cold clouds surrounding the protostar envelope, thanks to the very high quality of the Herschel-HIFI data and the unique ability of water to probe them. Several foreground clouds are also detected along the line of sight. The low H2O abundances in massive dense cores are in accordance with the expectation that high densities and low temperatures lead to freeze-out of water on dust grains. The spread in abundance values is not clearly linked to physical properties of the sources., Comment: 8 pages, 5 figures, accepted for publication the 15/07/2010 by Astronomy&Astrophysics as a letter in the Herschel-HIFI special issue

Published
2010
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15. Herschel observations of the hydroxyl radical (OH) in young stellar objects

Author

S. F. Wampfler, G. J. Herczeg, S. Bruderer, A. O. Benz, E. F. van Dishoeck, L. E. Kristensen, R. Visser, S. D. Doty, M. Melchior, T. A. van Kempen, U. A. Yıldız, C. Dedes, J. R. Goicoechea, A. Baudry, G. Melnick, R. Bachiller, M. Benedettini, E. Bergin, P. Bjerkeli, G. A. Blake, S. Bontemps, J. Braine, P. Caselli, J. Cernicharo, C. Codella, F. Daniel, A. M. di Giorgio, C. Dominik, P. Encrenaz, M. Fich, A. Fuente, T. Giannini, Th. de Graauw, F. Helmich, F. Herpin, M. R. Hogerheijde, T. Jacq, D. Johnstone, J. K. Jørgensen, B. Larsson, D. Lis, R. Liseau, M. Marseille, C. Mc Coey, D. Neufeld, B. Nisini, M. Olberg, B. Parise, J. C. Pearson, R. Plume, C. Risacher, J. Santiago-García, P. Saraceno, R. Shipman, M. Tafalla, F. F. S. van der Tak, F. Wyrowski, P. Roelfsema, W. Jellema, P. Dieleman, E. Caux, J. Stutzki, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), 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), 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), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], 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, ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Max-Planck-Institut für Radioastronomie (MPIFR), Low Energy Astrophysics (API, FNWI), École normale supérieure - Paris (ENS-PSL), 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), 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), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), and Astronomy

Subjects
Young stellar object, Astronomy, Flux, FOS: Physical sciences, Astrophysics, MOLECULAR CLOUD, CO OBSERVATIONS, 01 natural sciences, PHYSICAL STRUCTURE, Luminosity, chemistry.chemical_compound, Far infrared, 0103 physical sciences, Solar and Stellar Astrophysics, 010306 general physics, Absorption (electromagnetic radiation), Spectroscopy, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Line (formation), QB, Physics, stars: formation, PACS SPECTROSCOPY, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, astrochemistry, MASS PROTOSTARS, Astronomy and Astrophysics, CLASS-0 SOURCES, PHOTODISSOCIATION, FIRS 2, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], ISM: molecules, ISM: jets and outflows, chemistry, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, ISM: individual objects: HH 46, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Hydroxyl radical, EMISSION, HH 46
Abstract

Water in Star-forming regions with Herschel (WISH) is a Herschel Key Program investigating the water chemistry in young stellar objects (YSOs) during protostellar evolution. Hydroxyl (OH) is one of the reactants in the chemical network most closely linked to the formation and destruction of H2O. High-temperature chemistry connects OH and H2O through the OH + H2 H2O + H reactions. Formation of H2O from OH is efficient in the high-temperature regime found in shocks and the innermost part of protostellar envelopes. Moreover, in the presence of UV photons, OH can be produced from the photo-dissociation of H2O. High-resolution spectroscopy of the OH 163.12 micron triplet towards HH 46 and NGC 1333 IRAS 2A was carried out with the Heterodyne Instrument for the Far Infrared (HIFI) on board Herschel. The low- and intermediate-mass YSOs HH 46, TMR 1, IRAS 15398-3359, DK Cha, NGC 7129 FIRS 2, and NGC 1333 IRAS 2A were observed with the Photodetector Array Camera and Spectrometer (PACS) in four transitions of OH and two [OI] lines. The OH transitions at 79, 84, 119, and 163 micron and [OI] emission at 63 and 145 micron were detected with PACS towards the class I low-mass YSOs as well as the intermediate-mass and class I Herbig Ae sources. No OH emission was detected from the class 0 YSO NGC 1333 IRAS 2A, though the 119 micron was detected in absorption. With HIFI, the 163.12 micron was not detected from HH 46 and only tentatively detected from NGC 1333 IRAS 2A. The combination of the PACS and HIFI results for HH 46 constrains the line width (FWHM > 11 km/s) and indicates that the OH emission likely originates from shocked gas. This scenario is supported by trends of the OH flux increasing with the [OI] flux and the bolometric luminosity. Similar OH line ratios for most sources suggest that OH has comparable excitation temperatures despite the different physical properties of the sources., Comment: Accepted for publication in Astronomy and Astrophysics (Herschel special issue)

Published
2010
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16. Milli-arcsecond Astrophysics with VSI, the VLTI Spectro-imager in the ELT Era

Author

F. Malbet, D. Buscher, G. Weigelt, P. Garcia, M. Gai, D. Lorenzetti, J. Surdej, J. Hron, R. Neuhäuser, P. Kern, L. Jocou, J.-P. Berger, O. Absil, U. Beckmann, L. Corcione, G. Duvert, M. Filho, P. Labeye, E. Le Coarer, G. Li Causi, J. Lima, K. Perraut, E. Tatulli, E. Thiébaut, J. Young, G. Zins, A. Amorim, B. Aringer, T. Beckert, M. Benisty, X. Bonfils, A. Chelli, O. Chesneau, A. Chiavassa, R. Corradi, M. de Becker, A. Delboulbé, G. Duchêne, T. Forveille, C. Haniff, E. Herwats, K.-H. Hofmann, J.-B. Le Bouquin, S. Ligori, D. Loreggia, A. Marconi, A. Moitinho, B. Nisini, P.-O. Petrucci, J. Rebordao, R. Speziali, L. Testi, F. Vitali, 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), Cavendish Laboratory, University of Cambridge [UK] (CAM), Max-Planck-Institut für Radioastronomie (MPIFR), Laboratoire de Modélisation Multi-échelles des Combustibles (LM2C), Service d'Etudes de Simulation du Comportement du combustibles (SESC), Département d'Etudes des Combustibles (DEC), CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Département d'Etudes des Combustibles (DEC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), Osservatorio di Astrofisica di Roma (OAR), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Institut für Astrophysik [Wien], Universität Wien, Astrophysical Institute and University Observatory [Jena] (AIU), Friedrich-Schiller-Universität Jena, Institut d'Electronique du Solide et des Systèmes (InESS), Centre National de la Recherche Scientifique (CNRS), Centre d'Études Préhistoire, Antiquité, Moyen-Age (CEPAM), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto [Porto], Laboratoire d'Electronique et des Technologies de l'Information (CEA-LETI), Université Grenoble Alpes (UGA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), INAF - Osservatorio Astronomico di Roma (OAR), SIM/IDL Faculdade de Ciências da Universidade de Lisboa (FCUL), University of Lisboa, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut für Astronomie, Universität Wien (IFA), Laboratoire Gemini (LG), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Groupe de Recherche en Astronomie et Astrophysique du Languedoc (GRAAL), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofisica de Canarias (IAC), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Instituto Nacional de Engenharia, Tecnologia e Inovacco (INETI), European Southern Observatory (ESO), Department of Computer Science and Engineering [Bologna] (DISI), Università di Bologna [Bologna] (UNIBO), A. Moorwood, VSI collaboration, CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Universidade do Porto, Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Instituto Nacional de Engenharia, Tecnologia e Inovacao (INETI), Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Université Nice Sophia Antipolis (1965 - 2019) (UNS), Universidade do Porto = University of Porto, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Active galactic nucleus, Mode (statistics), Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Domain (software engineering), [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Stars, Interferometry, Wavelength, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

8 pages. To be published in the proceedings of the ESO workshop "Science with the VLT in the ELT Era", held in Garching (Germany) on 8-12 October 2007, A. Moorwood editor.; Nowadays, compact sources relatively warm like surfaces of nearby stars, circumstellar environments of stars from early stages to the most evolved ones and surroundings of active galactic nuclei can be investigated at milli-arcsecond scales only with the VLT in its interferometric mode. We propose a spectro-imager, named VSI (VLTI spectro-imager), which is capable to probe these sources both over spatial and spectral scales in the near-infrared domain. This instrument will provide information complementary to what is obtained at the same time with ALMA at different wavelengths and the extreme large telescopes.

Published
2009
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17. ASTRONOMY: Enhanced: Water's Role in Making Stars

Author

B, Nisini

Abstract

Water has long been believed to play an important role in star-forming regions as an oxygen reservoir and by cooling the circumstellar gas cloud, but observational evidence has been hard to come by. In her Perspective, Nisini explains how recent satellite missions have provided the first observational evidence that allows chemical models of star formation to be tested. Water is found to be initially low in abundance but to increase in abundance once a protostar has formed. The observations include protostars that are the precursors of sunlike stars, thus shedding light on water production in solar-type systems.

Published
2007

18. The distribution of gas and dust in the ρ oph cloud

Author

P. Saraceno, Yasuo Fukui, Sergio Molinari, Luigi Spinoglio, René Liseau, D. Lorenzetti, Akira Mizuno, C. Ceccarelli, and B. Nisini

Subjects
Physics, Distribution (number theory), Star formation, business.industry, Molecular cloud, Astronomy, Cloud computing, business
Published
2007
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20. ISO -LWS two-colour diagram of young stellar objects

Author

S. Pezzuto, F. Grillo, M. Benedettini, E. Caux, A. M. Di Giorgio, T. Giannini, S. J. Leeks, D. Lorenzetti, B. Nisini, P. Saraceno, L. Spinoglio, and E. Tommasi

Subjects
Physics, Spectrometer, Infrared, Young stellar object, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Photometry (optics), Wavelength, Stars, T Tauri star, Space and Planetary Science, Image resolution
Abstract

We present a [60--100] vs. [100--170] $��$m two colour diagram for a sample of 61 young stellar objects (YSOs) observed with the Long Wavelength Spectrometer (LWS) on-board the Infrared Space Observatory (ISO). The sample consists of 17 Class 0 sources, 15 Class I, 9 Bright Class I ($L_{\rm bol}>10^4 L_\odot$), 20 Class II (14 Herbig Ae/Be stars and 6 T Tauri stars). We find that each class occupies a well defined region in our diagram with colour temperatures increasing from Class 0 to Class II. Therefore the [60--100] vs. [100--170] two colours diagram is a powerful and simple tool to derive from future (e.g. with the Herschel Space Observatory) photometric surveys the evolutionary status of YSOs. The advantage over other tools already developed is that photometry at other wavelengths is not required: three flux measurements are enough to derive the evolutionary status of a source. As an example we use the colours of the YSO IRAS 18148$-$0440 to classify it as Class I. The main limitation of this work is the low spatial resolution of the LWS which, for some objects, causes a high uncertainty in the measured fluxes due to the background emission or to the source confusion inside the LWS beam., 7 pages, 2 figures, requires mn2e document class. Accepted by MNRAS

Published
2002

22. Measurements of near- and far-infrared zodiacal dust emission

Author

A. Salama, P. Andreani, G. dall'Oglio, P. Debernardis, S. Masi, B. Melchiorri, F. Melchiorri, G. Moreno, B. Nisini, and K. Shivanandan

Subjects
Physics, Zodiacal light, Infrared, media_common.quotation_subject, Astronomy, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Electromagnetic radiation, Wavelength, Far infrared, Space and Planetary Science, Sky, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Emission spectrum, Astrophysics::Galaxy Astrophysics, Cosmic dust, media_common
Abstract

Results concerning zodiacal dust emission are reported from an IR sky survey experiment performed during a balloon flight on July 30, 1984 which explored five wavelength bands centered at 11, 19, 50, 108, and 225 microns. The dust density n decreases at a rate slower than r exp -1.3 with increasing heliocentric distance. The trend of n depends critically on the radial variation of the temperature which, in turn, depends on the chemical composition of the grains. The spatial distribution of the dust is in good agreement with that previously inferred from IR measurements. A comparison between IR and optical observations points out the uncertainties affecting the estimates of the dust density obtained with both methods. The emission spectrum of the dust is used to discriminate among the different species of grains, showing that the observations can be accounted for by an appropriate mixture of graphite and silicates. 18 references.

Published
1987

23. The ODYSSEUS Survey. Motivation and First Results: Accretion, Ejection, and Disk Irradiation of CVSO 109

Author

C. C. Espaillat, G. J. Herczeg, T. Thanathibodee, C. Pittman, N. Calvet, N. Arulanantham, K. France, Javier Serna, J. Hernández, Á. Kóspál, F. M. Walter, A. Frasca, W. J. Fischer, C. M. Johns-Krull, P. C. Schneider, C. Robinson, Suzan Edwards, P. Ábrahám, Min Fang, J. Erkal, C. F. Manara, J. M. Alcalá, E. Alecian, R. D. Alexander, J. Alonso-Santiago, Simone Antoniucci, David R. Ardila, Andrea Banzatti, M. Benisty, Edwin A. Bergin, Katia Biazzo, César Briceño, Justyn Campbell-White, L. Ilsedore Cleeves, Deirdre Coffey, Jochen Eislöffel, Stefano Facchini, D. Fedele, Eleonora Fiorellino, Dirk Froebrich, Manuele Gangi, Teresa Giannini, K. Grankin, Hans Moritz Günther, Zhen Guo, Lee Hartmann, Lynne A. Hillenbrand, P. C. Hinton, Joel H. Kastner, Chris Koen, K. Maucó, I. Mendigutía, B. Nisini, Neelam Panwar, D. A. Principe, Massimo Robberto, A. Sicilia-Aguilar, Jeff A. Valenti, J. Wendeborn, Jonathan P. Williams, Ziyan Xu, R. K. Yadav, ITA, USA, GBR, FRA, DEU, and HUN

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

The Hubble UV Legacy Library of Young Stars as Essential Standards (ULLYSES) Director's Discretionary Program of low-mass pre-main-sequence stars, coupled with forthcoming data from ALMA and JWST, will provide the foundation to revolutionize our understanding of the relationship between young stars and their protoplanetary disks. A comprehensive evaluation of the physics of disk evolution and planet formation requires understanding the intricate relationships between mass accretion, mass outflow, and disk structure. Here we describe the Outflows and Disks around Young Stars: Synergies for the Exploration of ULLYSES Spectra (ODYSSEUS) Survey and present initial results of the classical T Tauri Star CVSO 109 in Orion OB1b as a demonstration of the science that will result from the survey. ODYSSEUS will analyze the ULLYSES spectral database, ensuring a uniform and systematic approach in order to (1) measure how the accretion flow depends on the accretion rate and magnetic structures, (2) determine where winds and jets are launched and how mass-loss rates compare with accretion, and (3) establish the influence of FUV radiation on the chemistry of the warm inner regions of planet-forming disks. ODYSSEUS will also acquire and provide contemporaneous observations at X-ray, optical, NIR, and millimeter wavelengths to enhance the impact of the ULLYSES data. Our goal is to provide a consistent framework to accurately measure the level and evolution of mass accretion in protoplanetary disks, the properties and magnitudes of inner-disk mass loss, and the influence of UV radiation fields that determine ionization levels and drive disk chemistry., accepted to ApJ

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24. Increasing Accretion in the Young Eruptive Star EX Lup

Author

Á. Kóspál, E. Fiorellino, P. Ábrahám, T. Giannini, and B. Nisini

Subjects
General Medicine
Abstract

We report on optical and near-infrared light curves of the young eruptive star EX Lupi, which has shown significant brightening in the past month, indicating a new accretion burst.

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25. The 2015–2016 Outburst of the Classical EXor V1118 Ori.

Author

T. Giannini, S. Antoniucci, D. Lorenzetti, U. Munari, G. Li Causi, C. F. Manara, B. Nisini, A. A. Arkharov, S. Dallaporta, A. Di Paola, A. Giunta, A. Harutyunyan, S. A. Klimanov, A. Marchetti, G. L. Righetti, A. Rossi, F. Strafella, and V. Testa

Subjects
METEOR showers, ACCRETION (Astrophysics), ASTRONOMICAL photometry, HIGH resolution spectroscopy, NUCLEAR excitation
Abstract

After a quiescence period of about 10 years, the classical EXor source V1118 Ori has undergone an accretion outburst in 2015 September. The maximum brightness ( mag) was reached in 2015 December and was maintained for several months. Since 2016 September, the source is in a declining phase. Photometry and low/high-resolution spectroscopy were obtained with MODS and LUCI2 at the Large Binocular Telescope, with the facilities at the Asiago 1.22 and 1.82 m telescopes, and with GIANO at the Telescopio Nazionale Galileo. The spectra are dominated by emission lines of H i and neutral metallic species. From line and continuum analysis we derive the mass accretion rate and its evolution during the outburst. Considering that extinction may vary between 1.5 and 2.9 mag, we obtain = 0.3–2.0 10−8M yr−1 in quiescence and = 0.2–1.9 10−6M yr−1 at the outburst peak. The Balmer decrement shape has been interpreted by means of line excitation models, finding that from quiescence to outburst peak, the electron density has increased from ∼2 109 cm−3 to ∼4 1011 cm−3. The profiles of the metallic lines are symmetric and narrower than 100 km s−1, while H i and He i lines show prominent wings extending up to ±500 km s−1. The metallic lines likely originate at the base of the accretion columns, where neutrals are efficiently shielded against the ionizing photons, while faster ionized gas is closer to the star. Outflowing activity is testified by the detection of a variable P Cyg-like profile of the Hα and He i 1.08 μm lines. [ABSTRACT FROM AUTHOR]

Published
2017
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26. SOLVING THE EXCITATION AND CHEMICAL ABUNDANCES IN SHOCKS: THE CASE OF HH 1.

Author

T. Giannini, S. Antoniucci, B. Nisini, F. Bacciotti, and L. Podio

Subjects
SPIN excitations, STELLAR activity, THERMODYNAMICS, ASTRONOMICAL surveys, ASTRONOMY
Abstract

We present deep spectroscopic (3600–24700 Å ) X-shooter observations of the bright Herbig–Haro object HH 1, one of the best laboratories to study the chemical and physical modifications caused by protostellar shocks on the natal cloud. We observe atomic fine structure lines, H i and He i recombination lines and H2 ro-vibrational lines (more than 500 detections in total). Line emission was analyzed by means of Non-local Thermal Equilibiurm codes to derive the electron temperature and density, and for the first time we are able to accurately probe different physical regimes behind a dissociative shock. We find a temperature stratification in the range 4000 K 80,000 K, and a significant correlation between temperature and ionization energy. Two density regimes are identified for the ionized gas, a more tenuous, spatially broad component (density ∼103 cm−3), and a more compact component (density 105 cm−3) likely associated with the hottest gas. A further neutral component is also evidenced, having a temperature ≲10,000 K and a density >104 cm−3. The gas fractional ionization was estimated by solving the ionization equilibrium equations of atoms detected in different ionization stages. We find that neutral and fully ionized regions co-exist inside the shock. Also, indications in favor of at least partially dissociative shock as the main mechanism for molecular excitation are derived. Chemical abundances are estimated for the majority of the detected species. On average, abundances of non-refractory/refractory elements are lower than solar of about 0.15/0.5 dex. This indicates the presence of dust inside the medium, with a depletion factor of iron of ∼40%. [ABSTRACT FROM AUTHOR]

Published
2015
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27. A LONG-LASTING QUIESCENCE PHASE OF THE ERUPTIVE VARIABLE V1118 ORI.

Author

D. Lorenzetti, S. Antoniucci, T. Giannini, A. Harutyunyan, A. A. Arkharov, V. M. Larionov, F. Cusano, A. Di Paola, G. Li Causi, B. Nisini, R. Speziali, and F. Vitali

Subjects
CATACLYSMIC variable stars, BINARY stars, VARIABLE stars, ACCRETION (Astrophysics), ASTROPHYSICAL fluid dynamics
Abstract

V1118 Ori is an eruptive variable belonging to the EXor class of pre-main-sequence stars whose episodic outbursts are attributed to disk accretion events. Since 2006, V1118 Ori has been in the longest quiescence stage ever observed between two subsequent outbursts in its recent history. We present near-infrared photometry of V1118 Ori carried out over the last eight years, along with complete spectroscopic coverage from 0.35 to 2.5 μm. Long term sampling of V1118 Ori in quiescence has never been performed, and hence we can benefit from the current circumstance by determining the lowest values (i.e., the zeroes) of the parameters to be used as reference for evaluating the physical changes typical of more active phases. A quiescence mass accretion rate of 1–3 × 10−9 yr−1 can be derived and the difference from previous determinations is discussed. Based on line emission and IR color analysis, a visual extinction of 1–2 mag is consistently derived, confirming that V1118 Ori (at least in quiescence) is a low-extinction T Tauri star with a bolometric luminosity of about 2.1 . An anti-correlation exists between the equivalent width of the emission lines and the underlying continuum. We searched the literature to evaluate whether or not such behavior is a common feature for the whole class. The anti-correlation is clearly recognizable for all of the available EXors in the optical range (Hβ and Hα lines); however, this is not as evident in the infrared (Paβ and Brγ lines). The observed anti-correlation supports the accretion-driven mechanism as the most likely to account for continuum variations. [ABSTRACT FROM AUTHOR]

Published
2015
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28. [O i] 63 μm JETS IN CLASS 0 SOURCES DETECTED BY HERSCHEL.

Author

B. Nisini, G. Santangelo, T. Giannini, S. Antoniucci, S. Cabrit, C. Codella, C. J. Davis, J. Eislöffel, L. Kristensen, G. Herczeg, D. Neufeld, and E. F. van Dishoeck

Subjects
*STELLAR activity, *ASTROPHYSICS, *STAR formation, *PROTOSTARS, *ACCRETION (Astrophysics)
Abstract

We present Herschel PACS mapping observations of the [O i] 63 μm line toward protostellar outflows in the L1448, NGC 1333-IRAS4, HH 46, BHR 71, and VLA 1623 star-forming regions. We detect emission spatially resolved along the outflow direction, which can be associated with a low-excitation atomic jet. In the L1448-C, HH 46 IRS, and BHR 71 IRS1 outflows this emission is kinematically resolved into blue- and redshifted jet lobes, having radial velocities up to 200 km s−1. In the L1448-C atomic jet the velocity increases with the distance from the protostar, similarly to what is observed in the SiO jet associated with this source. This suggests that [O i] and molecular gas are kinematically connected and that the latter could represent the colder cocoon of a jet at higher excitation. Mass flux rates ((O i)) have been measured from the [O i] 63 μm luminosity adopting two independent methods. We find values in the range (1–4) × 10−7 yr−1 for all sources except HH 46, for which an order of magnitude higher value is estimated. (O i) are compared with mass accretion rates (acc) onto the protostar and with derived from ground-based CO observations. (O i)/acc ratios are in the range 0.05–0.5, similar to the values for more evolved sources. (O i) in HH 46 IRS and IRAS4A are comparable to (CO), while those of the remaining sources are significantly lower than the corresponding (CO). We speculate that for these three sources most of the mass flux is carried out by a molecular jet, while the warm atomic gas does not significantly contribute to the dynamics of the system. [ABSTRACT FROM AUTHOR]

Published
2015
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29. Circumstellar Structures around Herbig AeBe Stars: A Direct Interferometric Insight

Author

S. Antoniucci, G. Li Causi, Francesco Paresce, Dario Lorenzetti, Davide Elia, Francesco Strafella, Teresa Giannini, Brunella Nisini, S., Antoniucci, G., LI CAUSI, D., Lorenzetti, B., Nisini, T., Giannini, Strafella, Francesco, and D. ELIA AND F., Paresce

Subjects
Interferometria, Physics, Stars, Interferometry, Stelle di pre sequenza, Spectral energy distribution, Astronomy, Herbig Ae/Be star, Sistemi planetari, Circumstellar disk, Main sequence, Dischi circumstellari
Published
2007
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30. ASTRONOMY: Enhanced: Water's Role in Making Stars.

Author

Nisini B

Abstract

Water has long been believed to play an important role in star-forming regions as an oxygen reservoir and by cooling the circumstellar gas cloud, but observational evidence has been hard to come by. In her Perspective, Nisini explains how recent satellite missions have provided the first observational evidence that allows chemical models of star formation to be tested. Water is found to be initially low in abundance but to increase in abundance once a protostar has formed. The observations include protostars that are the precursors of sunlike stars, thus shedding light on water production in solar-type systems.

Published
2000
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