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281 results on '"Galaxies et cosmologie"'

101. MALS-NOT: Identifying Radio-Bright Quasars for the MeerKAT Absorption Line Survey

Author

Francoise Combes, Patrick Petitjean, Pasquier Noterdaeme, A. Ranjan, Raghunathan Srianand, N. Gupta, Ashish Mahabal, Johan P. U. Fynbo, J.-K. Krogager, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Inter-University Centre for Astronomy and Astrophysics [Pune] (IUCAA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Chaire Galaxies et cosmologie, and Collège de France (CdF (institution))

Subjects
Infrared, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, Nordic Optical Telescope, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, 010306 general physics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, [PHYS]Physics [physics], Physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Quasar, Astrophysics - Astrophysics of Galaxies, Redshift, Square kilometre array, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

We present a preparatory spectroscopic survey to identify radio-bright, high-redshift quasars for the MeerKAT Absorption Line Survey (MALS). The candidates have been selected on the basis of a single flux density limit at 1.4 GHz (>200 mJy) together with mid-infrared color criteria from the Wide-field Infrared Survey Explorer (WISE). Through spectroscopic observations using the Nordic Optical Telescope, we identify 72 quasars out of 99 candidates targeted. We measure the spectroscopic redshifts based on characteristic, broad emission lines present in the spectra. Of these 72 quasars, 64 and 48 objects are at sufficiently high redshift (z>0.6 and z>1.4) to be used for the L-band and UHF-band spectroscopic follow-up with the Square Kilometre Array (SKA) precursor in South Africa: the MeerKAT., Accepted for publication in ApJS. Supplementary figure sets available in the source files

Published
2018
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102. Radial migration in a stellar galactic disc with thick components

Author

P. Di Matteo, A. Halle, Misha Haywood, Francoise Combes, Max-Planck-Institut für Astrophysik (MPA), Max-Planck-Gesellschaft, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Chaire Galaxies et cosmologie, and Collège de France (CdF (institution))

Subjects
Angular momentum, Bar (music), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Gravitational potential, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, [PHYS]Physics [physics], Physics, Spiral galaxy, 010308 nuclear & particles physics, Astronomy and Astrophysics, Radius, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Amplitude, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: stellar content, galaxies: structure, Astrophysics::Earth and Planetary Astrophysics, galaxies: evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

We study how migration affects stars of a galaxy with a thin stellar disc and thicker stellar components. The simulated galaxy has a strong bar and lasting spiral arms. We find that the amplitude of the churning (change in angular momentum) is similar for thin and thick components, and of limited amplitude, and that stars of all components can be trapped at the corotation of the bar. At the exception of those stars trapped at the corotation, we find that stars that are far from their initial guiding radius are more likely so due to blurring rather than churning effects. We compare the simulation to orbits integration with a fixed gravitational potential rotating at a constant speed. In the latter case, stars trapped at corotation are churned periodically outside and inside the corotation radius, with a zero net average. However, as the bar speed of the simulated galaxy decreases and its corotation radius increases, stars trapped at corotation for several Gyrs can be churned outwards on average. We study the location of extreme migrators (stars experimenting the largest churning) and find that extreme migrators come from regions on the leading side of the effective potential local maxima., Comment: Accepted for publication in Astronomy and Astrophysics (acceptance date: 06/03/18),15 pages, 22 figures

Published
2018
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103. Molecular gas properties of a lensed star-forming galaxy at z 3.6: a case study

Author

Benjamin Clément, Daniel Schaerer, Gregory Walth, Frédéric Boone, M. Zamojski, Kristina Nyland, Miroslava Dessauges-Zavadsky, Panos Sklias, Wiphu Rujopakarn, Eiichi Egami, Timothy D. Rawle, Harald Ebeling, Francoise Combes, Johan Richard, Jean-Paul Kneib, Observatoire de Genève, Department of Physics, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, 10330, Bangkok, Thailand, 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 de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Institute for Astronomy, University of Hawaii, Space Telescope Science Institute (STScI), Steward Observatory, University of Arizona, Ecole Polytechnique Federale de Lausanne (EPFL), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), National Radio Astronomy Observatory, Charlottesville (NRAO), and University of California, Center for Astrophysics and Space Sciences, 9500 Gilman Drive, San Diego, CA, 92093, USA

Subjects
Physics, Stellar mass, 010308 nuclear & particles physics, Star formation, Metallicity, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy, Redshift, Luminosity, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Galaxy formation and evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Galaxy cluster, Astrophysics::Galaxy Astrophysics
Abstract

We report on the galaxy MACSJ0032-arc at z=3.6314 discovered during the Herschel Lensing snapshot Survey of massive galaxy clusters, and strongly lensed by the cluster MACSJ0032.1+1808. The successful detections of its rest-frame UV, optical, FIR, millimeter, and radio continua, and of its CO emission enable us to characterize, for the first time at such a high redshift, the stellar, dust, and molecular gas properties of a compact star-forming galaxy with a size smaller than 2.5 kpc, a fairly low stellar mass of 4.8x10^9 Msun, and a moderate IR luminosity of 4.8x10^11 Lsun. We find that the bulk of the molecular gas mass and star formation seems to be spatially decoupled from the rest-frame UV emission. About 90% of the total star formation rate is undetected at rest-frame UV wavelengths because of severe obscuration by dust, but is seen through the thermal FIR dust emission and the radio synchrotron radiation. The observed CO(4-3) and CO(6-5) lines demonstrate that high-J transitions, at least up to J=6, remain excited in this galaxy, whose CO spectral line energy distribution resembles that of high-redshift submm galaxies, even though the IR luminosity of MACSJ0032-arc is ten times lower. This high CO excitation is possibly due to the compactness of the galaxy. We find evidence that this high CO excitation has to be considered in the balance when estimating the CO-to-H2 conversion factor. The inferred depletion time of the molecular gas in MACSJ0032-arc supports the decrease in the gas depletion timescale of galaxies with redshift, although to a lesser degree than predicted by galaxy evolution models. Instead, the measured molecular gas fraction as high as 60-79% in MACSJ0032-arc favors the continued increase in the gas fraction of galaxies with redshift as expected, despite the plateau observed between z~1.5 and z~2.5., Comment: 18 pages, 11 figures, 2 tables. Revised version accepted for publication in A&A

Published
2017

104. Molecular Gas Dominated 50 kpc Ram Pressure Stripped Tail of the Coma Galaxy D100

Author

Ming Sun, Michitoshi Yoshida, Francoise Combes, Jan Palouš, Luca Cortese, Jeffrey D. P. Kenney, Pavel Jáchym, Elke Roediger, Masafumi Yagi, Henry, Florence, China Agriculture University Net Center, 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), Hiroshima Astrophysical Science Center, Hiroshima University, Astronomical Institute, Czech Academy of Sciences, Bocni II 1401, 14100, Prague, Czech Republic, Department of Physics, University of Alabama, Department of Astronomy, Yale University, International Centre for Radio Astronomy Research, University of Western Australia (ICRAR), École normale supérieure - Paris (ENS-PSL), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Optical and Infrared Division, National Astronomical Observatory of Japan, Hiroshima Astrophysical Science Center, Hiroshima University, and Milne Centre for Astrophysics, Department of Physics & Mathematics, University of Hull, Hull, HU6 7RX, UK

Subjects
Stripping (chemistry), FOS: Physical sciences, Flux, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 0103 physical sciences, Coma Cluster, Surface brightness, 010303 astronomy & astrophysics, Galaxy cluster, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, Physics, [PHYS]Physics [physics], 010308 nuclear & particles physics, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Ram pressure, Radial velocity, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph]
Abstract

We have discovered large amounts of molecular gas, as traced by CO emission, in the ram pressure stripped gas tail of the Coma cluster galaxy D100 (GMP 2910), out to large distances of about 50 kpc. D100 has a 60 kpc long, strikingly narrow tail which is bright in X-rays and H{\alpha}. Our observations with the IRAM 30m telescope reveal in total ~ 10^9 M_sun of H_2 (assuming the standard CO-to-H_2 conversion) in several regions along the tail, thus indicating that molecular gas may dominate its mass. Along the tail we measure a smooth gradient in the radial velocity of the CO emission that is offset to lower values from the more diffuse H{\alpha} gas velocities. Such a dynamic separation of phases may be due to their differential acceleration by ram pressure. D100 is likely being stripped at a high orbital velocity >2200 km/s by (nearly) peak ram pressure. Combined effects of ICM viscosity and magnetic fields may be important for the evolution of the stripped ISM. We propose D100 has reached a continuous mode of stripping of dense gas remaining in its nuclear region. D100 is the second known case of an abundant molecular stripped-gas tail, suggesting that conditions in the ICM at the centers of galaxy clusters may be favorable for molecularization. From comparison with other galaxies, we find there is a good correlation between the CO flux and the H{\alpha} surface brightness in ram pressure stripped gas tails, over about 2 dex., Comment: Accepted for publication to ApJ

Published
2017
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105. Close entrainment of massive molecular gas flows by radio bubbles in the central galaxy of Abell 1795

Author

M. T. Hogan, Helen Russell, Paul Nulsen, P. Salomé, Alastair C. Edge, Andrew C. Fabian, Brian R. McNamara, Grant R. Tremblay, Francoise Combes, A. N. Vantyghem, Michael McDonald, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Collège de France (CdF), Fabian, Andrew [0000-0002-9378-4072], Apollo - University of Cambridge Repository, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique ( LERMA ), École normale supérieure - Paris ( ENS Paris ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université de Cergy Pontoise ( UCP ), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique ( CNRS ), Collège de France ( CdF ), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Chaire Galaxies et cosmologie, and Collège de France (CdF (institution))

Subjects
cooling flows, Active galactic nucleus, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Bubble, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Protein filament, X-shaped radio galaxy, 0103 physical sciences, galaxies: clusters: Abell 1795, 010306 general physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, galaxies: clusters: individual: Abell 1795, Star formation, Velocity gradient, Molecular cloud, Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present new ALMA observations tracing the morphology and velocity structure of the molecular gas in the central galaxy of the cluster Abell 1795. The molecular gas lies in two filaments that extend 5 - 7 kpc to the N and S from the nucleus and project exclusively around the outer edges of two inner radio bubbles. Radio jets launched by the central AGN have inflated bubbles filled with relativistic plasma into the hot atmosphere surrounding the central galaxy. The N filament has a smoothly increasing velocity gradient along its length from the central galaxy's systemic velocity at the nucleus to -370 km/s, the average velocity of the surrounding galaxies, at the furthest extent. The S filament has a similarly smooth but shallower velocity gradient and appears to have partially collapsed in a burst of star formation. The close spatial association with the radio lobes, together with the ordered velocity gradients and narrow velocity dispersions, show that the molecular filaments are gas flows entrained by the expanding radio bubbles. Assuming a Galactic $X_{\mathrm{CO}}$ factor, the total molecular gas mass is $3.2\pm0.2\times10^{9}$M$_{\odot}$. More than half lies above the N radio bubble. Lifting the molecular clouds appears to require an infeasibly efficient coupling between the molecular gas and the radio bubble. The energy required also exceeds the mechanical power of the N radio bubble by a factor of two. Stimulated feedback, where the radio bubbles lift low entropy X-ray gas that becomes thermally unstable and rapidly cools in situ, provides a plausible model. Multiple generations of radio bubbles are required to lift this substantial gas mass. The close morphological association then indicates that the cold gas either moulds the newly expanding bubbles or is itself pushed aside and shaped as they inflate., 14 pages, 9 figures, accepted to MNRAS

Published
2017
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106. Molecular gas content of shell galaxies

Author

Pierre-Alain Duc, Francoise Combes, Brisa Mancillas, Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Observatoire astronomique de Strasbourg (ObAS), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
Physics, 010308 nuclear & particles physics, Shell (structure), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Space (mathematics), Rotation, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Galaxy, Radial velocity, Stars, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Phase (matter), 0103 physical sciences, Dissipative system, Astrophysics::Earth and Planetary Astrophysics, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Shells are fine stellar structures identified by their arc-like shapes present around a galaxy and currently thought to be vestiges of galaxy interactions and/or mergers. The study of their number, geometry, stellar populations and gas content can help to derive the interaction/merger history of a galaxy. Numerical simulations have proposed a mechanism of shell formation through phase wrapping during a radial minor merger. Alternatively, there could be barely a space wrapping, when particles have not made any radial oscillation yet, but are bound by their radial expansion, or produce an edge-brightened feature. These can be distinguished, because they are expected to keep a high radial velocity. While shells are first a stellar phenomenon, HI and CO observations have revealed neutral gas associated with shells. Some of the gas, the most diffuse and dissipative, is expected to be driven quickly to the center if it is travelling on nearly radial orbits. Molecular gas, distributed in dense clumps, is less dissipative, and may be associated to shells, and determine their velocity, too difficult to obtain from stars. We present here a search for molecular gas in nine shell galaxies with the IRAM-30m telescope. Six of them are detected in their galaxy center, and in three galaxies, we clearly detect molecular gas in shells. The derived amount of molecular gas varies from 1.5 10$^8$ to 3.4 10$^9$ M$_\odot$ in the shells. For two of them (Arp 10 and NGC 3656), the shells are characteristic of an oblate system. Their velocity is nearly systemic, and we conclude that these shells are phase-wrapped. For the third one (NGCB3934) the shells appear to participate to the rotation, and follow up with higher spatial resolution is required to conclude., 14 pages. 26 figures. 3 tables. 1 appendix. Accepted to publication in A&A

Published
2019
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107. Molecular gas and star formation in the red-sequence counter-rotating disc galaxy NGC 4550

Author

Hyunjin Jeong, Lisa M. Young, Alison F. Crocker, Shinya Komugi, Sukyoung K. Yi, Martin Bureau, Francoise Combes, Sub-department of Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Department of Astronomy, Yonsei University, Institute of Astronomy, School of Science, University of Tokyo, 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), and Physics Department, New Mexico Institute of Mining and Technology

Subjects
Physics, Solar mass, 010308 nuclear & particles physics, Star formation, Astrophysics (astro-ph), Plateau de Bure Interferometer, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Disc galaxy, 01 natural sciences, Galaxy, Accretion (astrophysics), Stars, Far infrared, 13. Climate action, Space and Planetary Science, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics
Abstract

We present observations of the CO(1-0) emission in the central 750 pc (10 arcsec) of the counter-rotating disc galaxy NGC 4550, obtained at the Institut de Radioastronomie Millimetrique (IRAM) Plateau de Bure Interferometer. Very little molecular gas is detected, only 1 x 10^7 solar masses, and its distribution is lopsided, with twice as much molecular gas observed at positive relative velocities than at negative relative velocities. The velocity gradient in the CO(1-0) emission shows that the molecular gas rotates like the thicker of the two stellar discs, which is an unexpected alignment of rotations if the thinner disc was formed by a major gas accretion event. However, a simulation shows that the gas rotating like the thicker disc naturally results from the coplanar merger of two counter-rotating disc galaxies, demonstrating the feasibility of this scenario for the formation of NGC 4550. We investigate various star formation tracers to determine whether the molecular gas in NGC 4550 is currently forming stars. UV imaging data and optical absorption linestrengths both suggest a recent star formation episode; the best-fitting two population model to the UV-optical colours yields a mass of young stars of 5.9 x 10^7 solar masses with an age of 280 Myr. The best information on the current star formation rate is a far infrared-based upper limit of only 0.02 solar masses per year. We are thus witnessing NGC 4550 either in a dip within a bursty star formation period or during a more continuous low-level star formation episode., Comment: Accepted by MNRAS

Published
2016
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108. The molecular polar disc in NGC 2768

Author

Lisa M. Young, Martin Bureau, Alison F. Crocker, Francoise Combes, Sub-department of Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
Physics, Active galactic nucleus, Stellar population, 010308 nuclear & particles physics, Star formation, Astrophysics (astro-ph), FOS: Physical sciences, Plateau de Bure Interferometer, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy, Interstellar medium, Space and Planetary Science, 0103 physical sciences, Elliptical galaxy, Polar, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present CO(1-0) and CO(2-1) maps of the molecular polar disc in the elliptical galaxy NGC 2768 obtained at the IRAM Plateau de Bure Interferometer. The maps have a resolution of 2.6" x 2.3" and 1.2" x 1.2" for the CO(1-0) and CO(2-1) lines, respectively. The CO maps complete the unique picture of the interstellar medium (ISM) of NGC 2768; the dust, molecular gas, ionised gas and neutral hydrogen (HI) trace the recent acquisition of cold and cool gas over two orders of magnitude in radii (and much more in density). In agreement with the other ISM components, the CO distribution extends nearly perpendicularly to the photometric major axis of the galaxy. Velocity maps of the CO show a rotating polar disc or ring in the inner kiloparsec. This cool gas could lead to kinematic substructure formation within NGC 2768. However, the stellar velocity field and H-beta absorption linestrength maps from the optical integral-field spectrograph SAURON give no indication of a young and dynamically cold stellar population coincident with the molecular polar disc. Very recent or weak star formation, undetectable in linestrengths, nevertheless remains a possibility and could be at the origin of some of the ionised gas observed. Millimetre continuum emission was also detected in NGC 2768, now one of only a few low-luminosity active galactic nuclei with observed millimetre continuum emission., Comment: Accepted for publication in MNRAS, 11 pages, 8 figures

Published
2016
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109. Cold, clumpy accretion onto an active supermassive black hole

Author

Stefi A. Baum, Francoise Combes, Andrew C. Fabian, Grant R. Tremblay, Brian R. McNamara, G. Mark Voit, Michael McDonald, Megan Donahue, Michael W. Wise, Anaëlle Maury, Stephen Hamer, Jeremy S. Sanders, P. Salome, Alastair C. Edge, Yuan Li, Malcolm N. Bremer, Louise O. V. Edwards, Helen Russell, Tracy E. Clarke, Raymond Oonk, Timothy A. Davis, Roberto Galván-Madrid, Alice C. Quillen, Christopher P. O'Dea, C. Megan Urry, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Collège de France - Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Laboratoire AIM, and Université Paris Diderot - Paris 7 ( UPD7 ) -Centre d'Etudes de Saclay

Subjects
Active galactic nucleus, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Mass deficit, astro-ph.GA, Astrophysics::High Energy Astrophysical Phenomena, Galaxies and clusters, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, General Relativity and Quantum Cosmology, Interstellar medium, M–sigma relation, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, QB, Physics, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Supermassive black hole, Multidisciplinary, 010308 nuclear & particles physics, Astronomy, Astrophysics - Astrophysics of Galaxies, Black hole, 13. Climate action, Intermediate-mass black hole, Astrophysics of Galaxies (astro-ph.GA), Stellar black hole, Spin-flip, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - High Energy Astrophysical Phenomena
Abstract

Supermassive black holes in galaxy centres can grow by the accretion of gas, liberating energy that might regulate star formation on galaxy-wide scales. The nature of the gaseous fuel reservoirs that power black hole growth is nevertheless largely unconstrained by observations, and is instead routinely simplified as a smooth, spherical inflow of very hot gas. Recent theory and simulations instead predict that accretion can be dominated by a stochastic, clumpy distribution of very cold molecular clouds - a departure from the "hot mode" accretion model - although unambiguous observational support for this prediction remains elusive. Here we report observations that reveal a cold, clumpy accretion flow towards a supermassive black hole fuel reservoir in the nucleus of the Abell 2597 Brightest Cluster Galaxy (BCG), a nearby (redshift z=0.0821) giant elliptical galaxy surrounded by a dense halo of hot plasma. Under the right conditions, thermal instabilities can precipitate from this hot gas, producing a rain of cold clouds that fall toward the galaxy's centre, sustaining star formation amid a kiloparsec-scale molecular nebula that inhabits its core. The observations show that these cold clouds also fuel black hole accretion, revealing "shadows" cast by the molecular clouds as they move inward at about 300 kilometres per second towards the active supermassive black hole in the galaxy centre, which serves as a bright backlight. Corroborating evidence from prior observations of warmer atomic gas at extremely high spatial resolution, along with simple arguments based on geometry and probability, indicate that these clouds are within the innermost hundred parsecs of the black hole, and falling closer towards it., Published in the June 9th, 2016 issue of Nature

Published
2016
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110. Les galaxies

Author

Combes, Francoise, 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), Collège de France - Chaire Galaxies et cosmologie, and Collège de France (CdF (institution))

Subjects
[SDU]Sciences of the Universe [physics]
Abstract

International audience; Considerable progress has been made on galaxy formation and evolution in recent years, and new issues. The old Hubble classification according to the tuning fork of spirals, lenticulars and ellipticals, is still useful but has given place to the red sequence, the blue cloud and the green valley, showing a real bimodality of types between star forming galaxies (blue) and quenched ones (red). Large surveys have shown that stellar mass and environment density are the two main factors of the evolution from blue to red sequences. Evolution is followed directly with redshift through a look-back time of more than 12 billion years. The most distant galaxy at z=11. has already a stellar mass of a billion suns. In an apparent anti-hierarchical scenario, the most massive galaxies form stars early on, while essentially dwarf galaxies are actively star-formers now. This downsizing feature also applies to the growth of super-massive black holes at the heart of each bulgy galaxy. The feedback from active nuclei is essential to explain the distribution of mass in galaxies, and in particular to explain why the fraction of baryonic matter is so low, lower by more than a factor 5 than the baryonic fraction of the Universe. New instruments just entering in operation, like MUSE and ALMA, provide a new and rich data flow, which is developed in this series of articles.

Published
2016

111. Molecular Gas Filaments and Star-forming Knots Beneath an X-Ray Cavity in RXC J1504–0248

Author

Alastair C. Edge, Brian R. McNamara, Andrew C. Fabian, P. Salomé, Michael McDonald, Paul Nulsen, Helen Russell, A. N. Vantyghem, Francoise Combes, Institute for Computational Cosmology (ICC), Durham University, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Institute of Astronomy [Cambridge], and University of Cambridge [UK] (CAM)

Subjects
[PHYS]Physics [physics], Physics, Active galactic nucleus, 010308 nuclear & particles physics, Star formation, Galactic Center, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Galaxy, Protein filament, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Cluster (physics), Emission spectrum, Brightest cluster galaxy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics
Abstract

We present recent ALMA observations of the CO(1-0) and CO(3-2) emission lines in the brightest cluster galaxy of RXCJ1504.1$-$0248, which is one of the most extreme cool core clusters known. The central galaxy contains $1.9\times 10^{10}~M_{\odot}$ of molecular gas. The molecular gas morphology is complex and disturbed, showing no evidence for a rotationally-supported structure in equilibrium. $80\%$ of the gas is situated within the central 5 kpc of the galactic center, while the remaining gas is located in a 20 kpc long filament. The cold gas has likely condensed out of the hot atmosphere. The filament is oriented along the edge of a putative X-ray cavity, suggesting that AGN activity has stimulated condensation. This is enegetically feasible, although the morphology is not as conclusive as systems whose molecular filaments trail directly behind buoyant radio bubbles. The velocity gradient along the filament is smooth and shallow. It is only consistent with free-fall if it lies within $20^{\circ}$ of the plane of the sky. The abundance of clusters with comparably low velocities suggests that the filament is not free-falling. Both the central and filamentary gas are coincident with bright UV emission from ongoing star formation. Star formation near the cluster core is consistent with the Kennicutt-Schmidt law. The filament exhibits increased star formation surface densities, possibly resulting from either the consumption of a finite molecular gas supply or spatial variations in the CO-to-H$_2$ conversion factor., 15 pages, 10 figures, accepted in ApJ

Published
2018
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112. Stellar metallicity variations across spiral arms in disk galaxies with multiple populations

Author

Misha Haywood, Sergey Khoperskov, P. Di Matteo, Francoise Combes, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Chaire Galaxies et cosmologie, and Collège de France (CdF (institution))

Subjects
Metallicity, Population, FOS: Physical sciences, Perturbation (astronomy), Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Kinematics, 01 natural sciences, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, education, 010303 astronomy & astrophysics, galaxies: kinematics and dynamics, Astrophysics::Galaxy Astrophysics, Physics, education.field_of_study, Spiral galaxy, 010308 nuclear & particles physics, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: structure, Astrophysics::Earth and Planetary Astrophysics, galaxies: evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

This letter studies the formation of azimuthal metallicity variations in the disks of spiral galaxies in the absence of initial radial metallicity gradients. Using high-resolution $N$-body simulations, we model composite stellar discs, made of kinematically cold and hot stellar populations, and study their response to spiral arm perturbations. We find that, as expected, disk populations with different kinematics respond differently to a spiral perturbation, with the tendency for dynamically cooler populations to show a larger fractional contribution to spiral arms than dynamically hotter populations. By assuming a relation between kinematics and metallicity, namely the hotter the population, the more metal-poor it is, this differential response to the spiral arm perturbations naturally leads to azimuthal variations in the mean metallicity of stars in the simulated disk. Thus, azimuthal variations in the mean metallicity of stars across a spiral galaxy are not necessarily a consequence of the reshaping, by radial migration, of an initial radial metallicity gradient. They indeed arise naturally also in stellar disks which have initially only a negative vertical metallicity gradient., 5 pages, 6 figures, Accepted for publication in A&A Letters

Published
2018
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113. P CYGNI PROFILES OF MOLECULAR LINES TOWARD ARP 220 NUCLEI

Author

Francesco Costagliola, Marco Spaans, John Conway, Alison B. Peck, John H. Black, Kazushi Sakamoto, Junzhi Wang, Susanne Aalto, David J. Wilner, Martina C. Wiedner, Kapteyn Astronomical Institute, Institute of Astronomy and Astrophysics, Academia Sinica, Department of Radio and Space Science, Chalmers University of Technology, Harvard-Smithsonian Center for Astrophysics, Joint ALMA Observatory, Santiago, Kapteyn Astronomical Institute, University of Groningen, Department of Astronomy, Nanjing University, Observatoire de Paris, Université Paris sciences et lettres (PSL), 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), and Instrumentation et télédétection

Subjects
Infrared, galaxies: active, FOS: Physical sciences, ARP-220, Astrophysics, DIAGNOSTICS, Luminosity, SUBMILLIMETER ARRAY, INFRARED GALAXIES, medicine, Line (formation), Physics, galaxies: individual (Arp 220), Astronomy and Astrophysics, SUPERNOVAE, Astrophysics - Astrophysics of Galaxies, Redshift, Galaxy, STARBURSTS, medicine.anatomical_structure, CONTINUUM, Space and Planetary Science, OUTFLOWS, Astrophysics of Galaxies (astro-ph.GA), LUMINOSITY, Millimeter, Absorption (chemistry), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], galaxies: evolution, EMISSION, Nucleus
Abstract

We report ~100 pc (0.3") resolution observations of (sub)millimeter HCO+ and CO lines in the ultraluminous infrared galaxy Arp 220. The lines peak at two merger nuclei, with HCO+ being more spatially concentrated than CO. Asymmetric line profiles with blueshifted absorption and redshifted emission are discovered in HCO+(3-2) and (4-3) toward the two nuclei and in CO(3-2) toward one nucleus. We suggest that these P-Cygni profiles are due to ~100 km/s outward motion of molecular gas from the nuclei. This gas is most likely outflowing from the inner regions of the two nuclear disks rotating around individual nuclei, clearing the shroud around the luminosity sources there., ApJL in press, 6 pages

Published
2009
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114. PHYSICAL CONDITIONS IN THE INTERSTELLAR MEDIUM OF INTENSELY STAR-FORMING GALAXIES AT REDSHIFT∼2

Author

W. van Driel, F. Bournaud, Nicole P. H. Nesvadba, L. Chemin, P. Di Matteo, M. D. Lehnert, L. S. Douglas, L. Le Tiran, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Physics, Star formation, Velocity dispersion, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Redshift, Galaxy, Accretion (astrophysics), Space and Planetary Science, Galaxy formation and evolution, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Surface brightness, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, Line (formation)
Abstract

International audience; We analyze the physical conditions in the interstellar gas of 11 actively star-forming galaxies at z~2, based on integral-field spectroscopy from the ESO-VLT and Hubble Space Telescope/Near Infrared Camera and Multi-Object Spectrometer imaging. We concentrate on the high Halpha surface brightnesses, large line widths, line ratios, and the clumpy nature of these galaxies. We show that photoionization calculations and emission line diagnostics imply gas pressures and densities that are similar to the most intense nearby star-forming regions at z = 0 but over much larger scales (10-20 kpc). A relationship between surface brightness and velocity dispersion can be explained through simple energy injection arguments and a scaling set by nearby galaxies with no free parameters. The high velocity dispersions are a natural consequence of intense star formation thus regions of high velocity dispersion are not evidence for mass concentrations such as bulges or rings. External mechanisms such as cosmological gas accretion generally do not have enough energy to sustain the high velocity dispersions. In some cases, the high pressures and low gas metallicites may make it difficult to robustly distinguish between active galactic nucleus ionization cones and star formation, as we show for BzK-15504 at z = 2.38. We construct a picture where the early stages of galaxy evolution are driven by self-gravity which powers strong turbulence until the velocity dispersion is high. Then massive, dense, gas-rich clumps collapse, triggering star formation with high efficiencies and intensities as observed. At this stage, the intense star formation is likely self-regulated by the mechanical energy output of massive stars.

Published
2009
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115. A giant bar induced by a merger event at z = 0.4?

Author

Sebastien Peirani, Francois Hammer, Hector Flores, Yanbin Yang, Lia Athanassoula, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)

Subjects
FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Hubble sequence, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], symbols.namesake, Bulge, 0103 physical sciences, Galaxy formation and evolution, 010303 astronomy & astrophysics, Methods: N-body simulations, Astrophysics::Galaxy Astrophysics, Physics, Orbital elements, Spiral galaxy, 010308 nuclear & particles physics, Astrophysics (astro-ph), Retrograde motion, Galaxies: kinematics and dynamics, Galaxies: evolution, Astronomy and Astrophysics, Mass ratio, Galaxy, Galaxies: interactions, Space and Planetary Science, symbols, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

(Aims) We present a physical model of the formation of J033239.72-275154.7, a galaxy observed at z=0.41 and characterized by a big young bar of size 6 kpc. The study of this system is particularly interesting for understanding the connection between mergers and bars as well as the properties and fate of this system as it relates to disk galaxy formation. (Methods) We compare the morphological and kinematic properties of J033239.72-275154.7, the latter obtained by the GIRAFFE spectrograph, to those derived from the merger of two spiral galaxies described by idealized N-body simulations including a star formation prescription. (Results) We found that the general morphological shape and most of the dynamical properties of the object can be well reproduced by a model in which the satellite is initially put in a retrograde orbit and the mass ratio of the system is 1:3. In such a scenario, a bar forms in the host galaxy after the first passage of the satellite where an important fraction of available gas is consumed in an induced burst. In its later evolution, however, we find that J033239.72-275154.7, whose major progenitor was an Sab galaxy, will probably become a S0 galaxy. This is mainly due to the violent relaxation and the angular momentum loss experienced by the host galaxy during the merger process, which is caused by the adopted orbital parameters. This result suggests that the building of the Hubble sequence is significantly influenced by the last major collision. In the present case, the merger leads to a severe damage of the disk of the progenitor, leading to an evolution towards a more bulge dominated galaxy., 6 pages, 5 figures. Accepted for publication in A&A

Published
2009
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116. Gas flow models in the Milky Way embedded bars

Author

Francoise Combes, Nemesio Rodriguez-Fernandez, Institut de RadioAstronomie Millimétrique (IRAM), 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
Physics, Spiral galaxy, Mass distribution, Bar (music), Milky Way, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Star count, Galaxy, Gravitational potential, Space and Planetary Science, Bulge, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract

The gas distribution and dynamics in the inner Galaxy present many unknowns as the origin of the asymmetry of the longitude-velocity (lv) diagram of the Central Molecular Zone (CMZ). On the other hand, there are recent evidences in the stellar component of the presence of a nuclear bar that could be slightly lopsided. Our goal is to characterize the nuclear bar observed in 2MASS maps and to study the gas dynamics in the inner Milky Way taking into account this secondary bar. We have derived a realistic mass distribution by fitting 2MASS star counts maps with three components (disk, bulge and nuclear bar) and we have simulated the gas dynamics, in the deduced gravitational potential, using a sticky-particles code. Our simulations of the gas dynamics reproduce successfully the main characteristics of the Milky Way for a bulge orientation of 20-35 deg with respect to the Sun-Galactic Center (GC) line and a pattern speed of 30-40 km/s/kpc. In our models the Galactic Molecular Ring (GMR) is not an actual ring but the inner parts of the spiral arms, while the 3-kpc arm and its far side counterpart are lateral arms that contour the bar. Our simulations reproduce, for the first time, the parallelogram shape of the lv-diagram of the CMZ as the gas response to the nuclear bar. This bar should be oriented by an angle of ~60-75 deg with respect to the Sun-GC line and its mass amounts to (2-5.5)10e9 Msun. We show that the observed asymmetry of the CMZ cannot be due to lopsidedness of the nuclear bar as suggested by the 2MASS maps. We do not find clear evidences of lopsidedness in the stellar potential. We propose that the observed asymmetry of the central gas layer can be due to the infalling of gas into the CMZ in the l=1.3-complex, 28 pages, 6 tables, 14 figures. To appear in Astronomy and Astrophysics

Published
2008
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117. SPACE: the spectroscopic all-sky cosmic explorer

Author

A. Cimatti, M. Robberto, C. Baugh, S. V. W. Beckwith, R. Content, E. Daddi, G. De Lucia, B. Garilli, L. Guzzo, G. Kauffmann, M. Lehnert, D. Maccagni, A. Martínez-Sansigre, F. Pasian, I. N. Reid, P. Rosati, R. Salvaterra, M. Stiavelli, Y. Wang, M. Zapatero Osorio, M. Balcells, M. Bersanelli, F. Bertoldi, J. Blaizot, D. Bottini, R. Bower, A. Bulgarelli, A. Burgasser, C. Burigana, R. C. Butler, S. Casertano, B. Ciardi, M. Cirasuolo, M. Clampin, S. Cole, A. Comastri, S. Cristiani, J.-G. Cuby, F. Cuttaia, A. De Rosa, A. Diaz Sanchez, M. Di Capua, J. Dunlop, X. Fan, A. Ferrara, F. Finelli, A. Franceschini, M. Franx, P. Franzetti, C. Frenk, Jonathan P. Gardner, F. Gianotti, R. Grange, C. Gruppioni, A. Gruppuso, F. Hammer, L. Hillenbrand, A. Jacobsen, M. Jarvis, R. Kennicutt, R. Kimble, M. Kriek, J. Kurk, J.-P. Kneib, O. Le Fevre, D. Macchetto, J. MacKenty, P. Madau, M. Magliocchetti, D. Maino, N. Mandolesi, N. Masetti, R. McLure, A. Mennella, M. Meyer, M. Mignoli, B. Mobasher, E. Molinari, G. Morgante, S. Morris, L. Nicastro, E. Oliva, P. Padovani, E. Palazzi, F. Paresce, A. Perez Garrido, E. Pian, L. Popa, M. Postman, L. Pozzetti, J. Rayner, R. Rebolo, A. Renzini, H. Röttgering, E. Schinnerer, M. Scodeggio, M. Saisse, T. Shanks, A. Shapley, R. Sharples, H. Shea, J. Silk, I. Smail, P. Spanó, J. Steinacker, L. Stringhetti, A. Szalay, L. Tresse, M. Trifoglio, M. Urry, L. Valenziano, F. Villa, I. Villo Perez, F. Walter, M. Ward, R. White, S. White, E. Wright, R. Wyse, G. Zamorani, A. Zacchei, W. W. Zeilinger, F. Zerbi, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Space Telescope Science Institute (STScI), Institute for Computational Cosmology, Department of Physics, Durham University, Durham (ICC), Centre for Advanced Instrumentation, Department of Physics, Durham University (CfAI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Max-Planck-Institut für Astrophysik (MPA), Istituto di Astrofisica Spaziale e Fisica Cosmica - Milano (IASF-MI), Istituto Nazionale di Astrofisica (INAF), Brera, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Astronomie (MPIA), INAF-Osservatorio Astronomico di Trieste (INAF-OATs), European Southern Observatory (ESO), Università di Milano, University of Oklahoma, Instituto de Astrofísica de Canarias (IAC), Rheinische Friedrich-Wilhelms-Universität Bonn, Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-Bologna), Department of Earth Atmospheric and Planetary Sciences, MIT, The Royal Observatory (ROE), Goddard Space Flight Center, NASA, Astrophysics Science Division, INAF-Osservatorio Astronomico di Bologna (OABO), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universidad Politecnica de Cartagena (UPCT), University of Maryland, University of Arizona, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Università degli Studi di Padova = University of Padua (Unipd), University of Leiden, California Institute of Technology, Department of Astronomy (CALTECH), OpSys Project Consulting, University of Hertfordshire [Hatfield] (UH), Institute of Astronomy, University of Cambridge (IoA), Research and Scientific Support Department, ESA-ESTEC (RSSD), University of California, Santa Cruz (UCSC), Steward Observatory, University of Arizona, UC Riverside, INAF-Osservatorio Astrofisico di Arcetri (INAF-OAA), University of Bucharest, Institute for Astronomy, University of Hawaii, INAF-Osservatorio Astronomico di Padova, Princeton, Ecole Polytechnique Fédérale de Lausanne (EPFL), University of Oxford, Johns Hopkins University (JHU), Yale University, University of California, Los Angeles (UCLA), University of Vienna, Cimatti A., Robberto M., Baugh C., Beckwith S. V. W., Content R., Daddi E., De Lucia G., Garilli B., Guzzo L., Kauffmann G., Lehnert M., Maccagni D., Martínez-Sansigre A., Pasian F., Reid I. N., Rosati P., Salvaterra R., Stiavelli M., Wang Y., Osorio M. Zapatero, Balcells M., Bersanelli M., Bertoldi F., Blaizot J., Bottini D., Bower R., Bulgarelli A., Burgasser A., Burigana C., Butler R. C., Casertano S., Ciardi B., Cirasuolo M., Clampin M., Cole S., Comastri A., Cristiani S., Cuby J.-G., Cuttaia F., de Rosa A., Sanchez A. Diaz, di Capua M., Dunlop J., Fan X., Ferrara A., Finelli F., Franceschini A., Franx M., Franzetti P., Frenk C., Gardner Jonathan P., Gianotti F., Grange R., Gruppioni C., Gruppuso A., Hammer F., Hillenbrand L., Jacobsen A., Jarvis M., Kennicutt R., Kimble R., Kriek M., Kurk J., Kneib J.-P., Le Fevre O., Macchetto D., MacKenty J., Madau P., Magliocchetti M., Maino D., Mandolesi N., Masetti N., McLure R., Mennella A., Meyer M., Mignoli M., Mobasher B., Molinari E., Morgante G., Morris S., Nicastro L., Oliva E., Padovani P., Palazzi E., Paresce F., Garrido A. Perez, Pian E., Popa L., Postman M., Pozzetti L., Rayner J., Rebolo R., Renzini A., Röttgering H., Schinnerer E., Scodeggio M., Saisse M., Shanks T., Shapley A., Sharples R., Shea H., Silk J., Smail I., Spanó P., Steinacker J., Stringhetti L., Szalay A., Tresse L., Trifoglio M., Urry M., Valenziano L., Villa F., Perez I. Villo, Walter F., Ward M., White R., White S., Wright E., Wyse R., Zamorani G., Zacchei A., Zeilinger W., Zerbi F., Cimatti, A., Robberto, M., Baugh, C., Beckwith, S. V. W., Content, R., Daddi, E., De, Lucia, G., Garilli, B., Guzzo, L., Kauffmann, Ferrara, Andrea, and 113, Coauthors

Subjects
Observational cosmology, media_common.quotation_subject, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Space (mathematics), law.invention, Telescope, law, Dark energy, Spectral resolution, media_common, Physics, COSMIC cancer database, Astronomical and space-research instrumentation, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Billion years, Galaxy, Redshift, Space and Planetary Science, Sky, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

We describe the scientific motivations, the mission concept and the instrumentation of SPACE, a class-M mission proposed for concept study at the first call of the ESA Cosmic-Vision 2015-2025 planning cycle. SPACE aims to produce the largest three-dimensional evolutionary map of the Universe over the past 10 billion years by taking near-IR spectra and measuring redshifts for more than half a billion galaxies at 0, Comment: 27 pages, Experimental Astronomy, in press. The SPACE team complete list is available at http://urania.bo.astro.it/cimatti/space . The article with full resolution figures is available at http://urania.bo.astro.it/cimatti/space/publications.htm

Published
2008
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118. Cold gas in the Perseus cluster core: excitation of molecular gas in filaments

Author

Francoise Combes, R. M. Johnstone, P. Salomé, Alastair C. Edge, Yves Revaz, Andrew C. Fabian, Nina A. Hatch, Institut de RadioAstronomie Millimétrique (IRAM), 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Ecole Polytechnique Fédérale de Lausanne (EPFL), Department of Physics, University of Durham, South Road, Leiden Observatory, and Institute of Astronomy, University of Cambridge (IoA)

Subjects
galaxies : cooling flows, Ngc 1275, Tidal Dwarf Galaxies, FOS: Physical sciences, galaxies : elliptical and lenticular, cD, Astrophysics, Cooling-Flow Clusters, IRAM 30m telescope, law.invention, Emission, Protein filament, Telescope, law, Cluster (physics), Region, galaxies : individual : NGC 1275, Emission spectrum, Line (formation), Physics, Ngc-1275, galaxies : intergalactic medium, Astrophysics (astro-ph), Astronomy and Astrophysics, HERA, Galaxy, Space and Planetary Science, High-Velocity System, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Hydrogen
Abstract

We have recently detected CO lines in the well-known filaments around NGC 1275, the galaxy at the centre of the Perseus cluster of galaxies. These previous observations, with the HERA multi-beam array at the IRAM 30m telescope enabled us to make a large map of the CO(2-1) line and to see hints of molecular gas far away from the cluster centre. To confirm the presence of CO emission lines in the outer filaments and to study the CO(2-1)/CO(1-0) line ratio, we observed seven regions of interest again with the 30m telescope in both CO(1-0) and CO(2-1). The regions we observed were: the eastern filament, the horseshoe, the northern filament and a southern extension, all selected from Halpha emission line mapping. Molecular gas is detected in all the observed regions. This result confirms the large extent of the cold molecular gas filaments. We discuss the CO(2-1)/CO(1-0) ratios in the filaments. The eastern filament has optically thick gas, whereas further away, the line ratio increases close to values expected for a warmer optically thin medium. We also show CO(1-0) and CO(2-1) lines in 9 regions closer to the centre. The kinematics of the CO is studied here in more detail and confirms that it follows the motions of the warm H_2 gas found in the near-infrared. Finally, we searched for dense gas tracers around 3C84 and claim here the first detection of HCN(3-2)., Comment: 10 pages, 6 figures, A&A in press

Published
2008
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119. Hα kinematics of the Spitzer Infrared Nearby Galaxies Survey – II

Author

A. Boselli, L. Chemin, Oscar F. Hernández, Chantal Balkowski, M.-M. de Denus-Baillargeon, Philippe Amram, Claude Carignan, Isabelle Dicaire, Kambiz Fathi, Olivier Daigle, Robert C. Kennicutt, Laboratoire d'Astrophysique Expérimentale (LAE), Observatoire du Mont Mégantic, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofísica de Canarias (IAC), and Institute of Astronomy, University of Cambridge (IoA)

Subjects
Luminous infrared galaxy, Physics, 010308 nuclear & particles physics, Galactic Center, Dark matter, Astronomy, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Kinematics, Astrophysics, 01 natural sciences, Radial velocity, Space and Planetary Science, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, Spitzer Infrared Nearby Galaxies Survey, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Galaxy rotation curve
Abstract

International audience; This is the second part of an Halpha kinematics follow-up survey of the Spitzer Infrared Nearby Galaxies Survey (SINGS) sample. The aim of this paper is to shed new light on the role of baryons and their kinematics and on the dark/luminous matter relation in the star-forming regions of galaxies, in relation with studies at other wavelengths. The data for 37 galaxies are presented. The observations were made using Fabry-Perot interferometry with the photon-counting camera FaNTOmM on four different telescopes, namely the Canada-France-Hawaii 3.6-m, the ESO La Silla 3.6-m, the William Herschel 4.2-m and the Observatoire du mont Mégantic 1.6-m telescopes. The velocity fields are computed using custom IDL routines designed for an optimal use of the data. The kinematical parameters and rotation curves are derived using the GIPSY software. It is shown that non-circular motions associated with galactic bars affect the kinematical parameters fitting and the velocity gradient of the rotation curves. This leads to incorrect determinations of the baryonic and dark matter distributions in the mass models derived from those rotation curves.

Published
2008
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120. Spectroscopic ages and metallicities of stellar populations: validation of full spectrum fitting

Author

Caroline Soubiran, D. Le Borgne, Pierre Ocvirk, Ph. Prugniel, Mina Koleva, University of Sofia, 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-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), 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 astronomique de Strasbourg (OAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Sofia University 'St. Kliment Ohridski', Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Astrophysikalisches Institut Potsdam (AIP), Pomies, Marie-Paule, Софийски университет = Sofia University, and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
FOS: Physical sciences, Astrophysics, [SDU.ASTR] Sciences of the Universe [physics]/Astrophysics [astro-ph], 01 natural sciences, Blue straggler, Spectral line, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Galaxy groups and clusters, 0103 physical sciences, Spectral resolution, Spectroscopy, 010303 astronomy & astrophysics, Physics, Galaxy: stellar content, (Galaxy:) globular clusters: general, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astrophysics (astro-ph), Astronomy and Astrophysics, Horizontal branch, Stars, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Space and Planetary Science, Globular cluster, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], techniques: spectroscopic
Abstract

Fitting whole spectra at intermediate spectral resolution (R = 1000 -- 3000), to derive physical properties of stellar populations, appears as an optimized alternative to methods based on spectrophotometric indices: it uses all the redundant information contained in the signal. This paper addresses the validation of the method and it investigates the quality of the population models together with the reliability of the fitting procedures. We are using two algorithms: STECKMAP, a non-parametric regularized program and NBURSTS a parametric non-linear minimization. We compare three spectral synthesis models for single stellar populations: Pegase-HR, Galaxev (BC03) and Vazdekis/Miles, and we analyse spectra of Galactic clusters whose populations are known from studies of color-magnitude diagrams (CMD) and spectroscopy of individual stars. We find that: (1) The quality of the models critically depends on the stellar library they use. Pegase-HR and Vazdekis/Miles are consistent, while the comparison between Pegase-HR and BC03 shows some systematics reflecting the limitations of the stellar library (STELIB) used to generate the latter models; (2) The two fitting programs are consistent; (3) For globular clusters and M67 spectra, the method restitutes metallicities in agreement with spectroscopy of stars within 0.14 dex; (4) The spectroscopic ages are very sensitive to the presence of a blue horizontal branch (BHB) or of blue stragglers. A BHB morphology results in a young SSP-equivalent age. Fitting a free amount of blue stars in addition to the SSP model to mimic the BHB improves and stabilizes the fit and restores ages in agreement with CMDs studies. This method is potentially able to disentangle age or BHB effects in extragalactic clusters., Comment: accepted in MNRAS; Full version available at http://www-obs.univ-lyon1.fr/labo/perso/prugniel/mina/koleva.pdf

Published
2008
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121. Molecular Gas in NUclei of GAlaxies (NUGA)

Author

Frédéric Boone, Leslie K. Hunt, Francoise Combes, Andreas Eckart, Stephane Leon, Santiago García-Burillo, Eva Schinnerer, Melanie Krips, Andrew J. Baker, Roberto Neri, Linda J. Tacconi, Istituto di Radioastronomia, Firenze, 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Observatorio Astronomico Nacional, Madrid, Max-Planck-Institut für Astronomie (MPIA), Harvard-Smithsonian Center for Astrophysics, Department of Physics and Astronomy, State University of New Jersey, Physikalisches Institut, Universität zu Köln, Instituto de Radio Astronomía Milimétrica (IRAM), Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), and Max-Planck-Institut für Extraterrestriche Physik (MPE)

Subjects
Physics, Spiral galaxy, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Inflow, Astrophysics, Dissipation, Galaxy, Dust lane, Space and Planetary Science, Perpendicular, Astrophysics::Earth and Planetary Astrophysics, Pitch angle, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Lindblad resonance, Astrophysics::Galaxy Astrophysics
Abstract

We present CO(1-0) and CO(2-1) maps of the starburst/Seyfert 1 galaxy NGC 2782, obtained with the IRAM interferometer. The CO emission is aligned along the stellar nuclear bar of radius 1 kpc, configured in an elongated structure with two spiral arms at high pitch angle. At the extremity of the nuclear bar, the CO changes direction to trace two more extended spiral features at a lower pitch angle. These are the beginning of two straight dust lanes, which are aligned parallel to an oval distortion, reminiscent of a primary bar, almost perpendicular to the nuclear one. The two embedded bars appear in Spitzer IRAC near-infrared images, and HST color images, although highly obscured by dust in the latter. We compute the torques exerted by the stellar bars on the gas, and find systematically negative average torques down to the resolution limit of the images, providing evidence of gas inflow tantalizingly close to the nucleus of NGC 2782. The observations are well reproduced by numerical simulations, including gas dissipation, which predict the secondary bar decoupling, the formation of an elongated ring at the 1 kpc-radius Inner Lindblad Resonance (ILR) of the primary bar, and the gas inflow to the ILR of the nuclear bar. The presence of molecular gas inside the ILR of the primary bar, transported by a second nuclear bar, is a potential ``smoking gun''; the gas there is certainly fueling the central starburst, and in a second step could fuel directly the AGN., 23 pages, 18 figures, accepted for publication in A&A; revised 28/2/2008 with additional references for Section 7.2

Published
2008
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122. Formation of cold filaments in cooling flow clusters

Author

Yves Revaz, Francoise Combes, P. Salomé, 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Institut de RadioAstronomie Millimétrique (IRAM), and Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Radiative cooling, Astrophysics::High Energy Astrophysical Phenomena, Bubble, Astrophysics (astro-ph), Center (category theory), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Radius, Plasma, Wake, Cooling flow, Physics::Fluid Dynamics, Space and Planetary Science, Cluster (physics), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract

Emission-lines in the form of filamentary structures is common in bright clusters characterized by short cooling times. In the Perseus cluster, cold molecular gas, tightly linked to the H$\alpha$ filaments, has been recently revealed by CO observations. In order to understand the origin of these filamentary structures, we have investigated the evolution of the hot ICM gas perturbed by the AGN central activity in a Perseus like cluster. Using very-high resolution TreeSPH simulations combined with a multiphase model and a model of plasma bubbles, we have been able to follow the density and temperature evolution of the disturbed ICM gas around the bubbles. Our simulations show that a fraction of the $1-2 \rm{keV}$ gas present at the center of clusters is trapped and entrained by the rising buoyant bubble to higher radius where the AGN heating is less efficient. The radiative cooling makes it cool in a few tens of Myr below $10^4 \rm{K}$, forming cold filamentary structures in the wake and in the rim of the bubbles., Comment: 4 Pages, 3 figures + online material ; Accepted for publication in A&A Letters. Higher resolution version may be downloaded here http://aramis.obspm.fr/~revaz/aa.2007.8915/

Published
2007
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123. IMAGES. I. Strong evolution of galaxy kinematics since z = 1

Author

Joel Vernet, Nicole P. H. Nesvadba, C. J. Cesarsky, Herve Wozniak, Hector Flores, S. diSeregoAlighieri, I. Fuentes-Carrera, D. Vergani, M. D. Lehnert, B. Guiderdoni, Lucia Pozzetti, Ajit K. Kembhavi, Benoit Neichel, Mathieu Puech, F. Hammer, Yun-Feng Liang, Helmut Dannerbauer, Göran Östlin, P. Amram, Chantal Balkowski, C. D. Ravikumar, Y. Yang, A. Rawat, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Observatoire de Paris - Site de Paris (OP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Bologna (OABO), Istituto Nazionale di Astrofisica (INAF), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de 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), Beaussier, Catherine, Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Astronomie du LESIA, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, European Southern Observatory (ESO), Inter-University Centre for Astronomy and Astrophysics (IUCAA), INAF-Osservatorio Astronomico di Bologna (OABO), Max-Planck-Institut für Astronomie (MPIA), INAF-Osservatorio Astrofisico di Arcetri (INAF-OAA), National Astronomical Observatoires-CAS, Stockholm Observatory, AlbaNova University Center, Department of Physics, University of Calicut, and Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-Milano)

Subjects
Population, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Kinematics, 01 natural sciences, Measure (mathematics), [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Emission spectrum, education, Spectroscopy, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, education.field_of_study, 010308 nuclear & particles physics, Astrophysics (astro-ph), Astronomy and Astrophysics, Cosmic variance, Redshift, Galaxy, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Space and Planetary Science, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

(abbreviated) We present the first results of the ESO large program, ``IMAGES'' which aims at obtaining robust measurements of the kinematics of distant galaxies using the multi-IFU mode of GIRAFFE on the VLT. 3D spectroscopy is essential to robustly measure the often distorted kinematics of distant galaxies (e.g., Flores et al. 2006). We derive the velocity fields and $\sigma$-maps of 36 galaxies at 0.4 15 A) at z=0.4-0.75, which are a representative subsample of the population of M_stellar>1.5x10^{10} M_sun emission line galaxies in this redshift range, and are largely unaffected by cosmic variance. Taking into account all galaxies -with or without emission lines- in that redshift range, we find that at least 41+/-7% of them have anomalous kinematics, i.e., they are not dynamically relaxed. This includes 26+/-7% of distant galaxies with complex kinematics, i.e., they are not simply pressure or rotationally supported. Our result implies that galaxy kinematics are among the most rapidly evolving properties, because locally, only a few percent of the galaxies in this mass range have complex kinematics., Comment: 17 pages, 6 figures, Accepted by A&A

Published
2007
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124. CO investigation of z = 0.4–1.5 galaxies

Author

Francoise Combes, A.-L. Melchior, 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), and Sorbonne Université (SU)

Subjects
Luminous infrared galaxy, Physics, Radio galaxy, Infrared, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Upper and lower bounds, Redshift, Galaxy, Space and Planetary Science, Content (measure theory), Emission spectrum, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

We report on the results of an IRAM-30m search for CO emission lines in three galaxies at intermediate redshifts. The idea was to investigate the molecular content of galaxies bright in the infrared at z=0.4-1.5, a redshift desert for molecular line studies, poorly investigated as of yet. We integrated 8-10h per source and did not succeed in detecting any of the sources. From our upper limits, we are able to constrain the molecular gas content in these systems to less than 4 to 8 x 10^9 Mo, assuming a CO-to-H_2 conversion factor (\alpha=0.8 Mo/(K km s^-1 pc^2)). We stress the current difficulty of selecting sources with a detectable molecular content, a problem that will be faced by the ALMA First Science projects., Comment: 6 pages, 5 figures. Accepted for publication in Astronomy and Astrophysics

Published
2007
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125. Astrometric data for NEAs extracted from the infrared DENIS survey

Author

G. Simon, William Thuillot, Jérôme Berthier, J. Iglesias, Valery Lainey, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Jin, W. J., Platais, I., Perryman, and M. A. C.

Subjects
Physics, Space and Planetary Science, Asteroid, Infrared, Astronomy, Astronomy and Astrophysics, Astrometry, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrobiology
Abstract

When astrometric data can be extracted from archives, this generally allows us to get very strong constraints for the orbital modeling of Solar System objects. This is particularly important for Near-Earth Asteroids. We have developed tools in the Virtual Observatory framework in order to carry out such a task. We have applied them to the DENIS survey. This survey has been performed from 1995 to 2001 in the I, J, K' spectral bands with a 1m telescope at ESO La Silla. Many sources associated to Solar System Objects have been identified and we present our preliminary results.

Published
2007
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126. Molecular gas in high-velocity clouds: revisited scenario

Author

Francoise Combes, Daniel Pfenniger, Miroslava Dessauges-Zavadsky, Observatoire Astronomique de l'Université de Genève, 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
Physics, Infrared, Metallicity, High velocity, Astrophysics (astro-ph), Resolution (electron density), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, law.invention, Interstellar medium, Telescope, Space and Planetary Science, law, Cirrus, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Intensity (heat transfer)
Abstract

We report a new search for 12CO(1-0) emission in high-velocity clouds (HVCs) performed with the IRAM 30 m telescope. This search was motivated by the recent detection of cold dust emission in the HVCs of Complex C. Despite a spatial resolution which is three times better and sensitivity twice as good compared to previous studies, no CO emission is detected in the HVCs of Complex C down to a best 5 sigma limit of 0.16 K km/s at a 22'' resolution. The CO emission non-detection does not provide any evidence in favor of large amounts of molecular gas in these HVCs and hence in favor of the infrared findings. We discuss different configurations which, however, allow us to reconcile the negative CO result with the presence of molecular gas and cold dust emission. H2 column densities higher than our detection limit, N(H2) = 3x10^{19} cm^{-2}, are expected to be confined in very small and dense clumps with 20 times smaller sizes than the 0.5 pc clumps resolved in our observations according to the results obtained in cirrus clouds, and might thus still be highly diluted. As a consequence, the inter-clump gas at the 1 pc scale has a volume density lower than 20 cm^{-3} and already appears as too diffuse to excite the CO molecules. The observed physical conditions in the HVCs of Complex C also play an important role against CO emission detection. It has been shown that the CO-to-H2 conversion factor in low metallicity media is 60 times higher than at the solar metallicity, leading for a given H2 column density to a 60 times weaker integrated CO intensity. And the very low dust temperature estimated in these HVCs implies the possible presence of gas cold enough (< 20 K) to cause CO condensation onto dust grains under interstellar medium pressure conditions and thus CO depletion in gas-phase observations., 9 pages, 4 figures, Accepted for publication in A&A

Published
2007
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127. HCG 31: a multiple merger in progress

Author

C. Mendes de Oliveira, Henri Plana, Philippe Amram, Olivier Hernandez, Chantal Balkowski, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Departamento de Astronomia Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, Laboratorio de Astrofísica Teórica e Observacional, DCET, Universidade Estadual de Santa Cruz, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), and Laboratoire d'Astrophysique Expérimentale (LAE), Observatoire du Mont Mégantic

Subjects
Physics, Astronomy, Velocity dispersion, Astronomy and Astrophysics, Context (language use), Astrophysics::Cosmology and Extragalactic Astrophysics, Kinematics, Astrophysics, Galaxy, Compact group, Space and Planetary Science, Galaxy formation and evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, Galaxy rotation curve, Dwarf galaxy
Abstract

International audience; Context: HCG 31 is one of the most intriguing compact groups in Hickson's catalogue. It contains a central pair of interacting dwarf galaxies and other small members that are highly peculiar. Aims: The main goal of this study is to investigate the evolutionary stage of the group and measure the internal kinematics of the individual galaxies and of the possible tidal dwarf galaxies. Methods: We obtained new Fabry-Perot data cubes, including Halpha images, velocity fields, velocity dispersion maps, lambda maps, position-velocity plots and rotation curves. We have taken advantage of the high spatial (sampling of ~0.4 arcsec) and spectral (velocity sampling of ~3 km s-1) resolutions of our Fabry-Perot data. Results: Kinematic peculiarities and overlapping double velocity components are measurable throughout the velocity field of A+C, with no signature of either distinct rotating disks or a single rotating galaxy. The velocity dispersion map shows widespread low-velocity values throughout the group (consistent with the turbulent velocity of the gas), except in a narrow interface between A and C, where the merging may be occurring. The velocity curves of four candidate tidal dwarf galaxies (regions E, F, A1, and A2) show flat velocity patterns in two cases (A1 and F) and gradients with amplitudes of A˜ 30-40 km s-1~in two others (E and A2). Our measurements show good agreement with previous optical literature data, but our data set has a much improved velocity sampling and deeper coverage. Moreover, within the star-forming regions of the group, our data profit from the higher spatial resolution with respect to HI data. Conclusions: The dynamics of the A+C system, with two main velocity components of approximately the same intensities, indicate that it is in a pre-merger stage. The two disks, in a bound orbit and in the process of merging, have had at least one earlier passage. They rotate with almost parallel spin axes like a set of gear wheels. This prograde encounter and the high star-formation rates favor the formation of a new disk. Object F may turn into a tidal dwarf galaxy bound to the group.

Published
2007
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128. Fueling the central engine of radio galaxies

Author

Jeremy Lim, Stephane Leon, Santiago García-Burillo, Asunción Fuente, Antonio Usero, Roberto Neri, Francoise Combes, Observatorio Astronomico Nacional, Madrid, 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofisica de Andalucia, CSIC (IAA), and Institute of Astronomy and Astrophysics, Academia Sinica

Subjects
Physics, Space and Planetary Science, Radio galaxy, Astrophysics (astro-ph), FOS: Physical sciences, Plateau de Bure Interferometer, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract

We report the detection of a massive (M(gas) > 5x10^9 Msun) molecular/dusty disk of 1.4kpc-size fueling the central engine of the Compact Symmetric Object (CSO) 4C31.04 based on high-resolution (0.5''--1.2'') observations done with the IRAM Plateau de Bure interferometer (PdBI). These observations allow for the first time to detect and map the continuum emission from dust at 218GHz in the disk of a CSO. The case for a massive disk is confirmed by the detection of strong HCO+(1--0) line emission and absorption. The molecular gas mass of 4C31.04 is in the range 0.5x10^10--5x10^10Msun. While the distribution and kinematics of the gas correspond roughly to those of a rotating disk, we find evidence of distortions and non-circular motions suggesting that the disk is not in a dynamically relaxed state. We discuss the implications of these results for the general understanding of the evolution of radio galaxies., 5 pages, 3 figures, Accepted (25/04/2007) in A&A Letters

Published
2007
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129. Kinematics and stellar populations of the dwarf elliptical galaxy IC 3653

Author

Olga K. Sil'chenko, Philippe Prugniel, Igor Chilingarian, V. L. Afanasiev, Shternberg State Institute of Astronomy (SSIA), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de 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), 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), Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), and Special Astrophysical Observatory, Russian Academy of Sciences

Subjects
Effective radius, Physics, education.field_of_study, Metallicity, Astrophysics (astro-ph), Population, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy, Spectral line, Space and Planetary Science, Elliptical galaxy, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Dwarf elliptical galaxy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Irregular galaxy, education, Astrophysics::Galaxy Astrophysics
Abstract

We present the first 3D observations of a diffuse elliptical galaxy (dE). The good quality data (S/N up to 40) reveal the kinematical signature of an embedded stellar disc, reminiscent of what is commonly observed in elliptical galaxies, though similarity of their origins is questionable. Colour map built from HST ACS images confirms the presence of this disc. Its characteristic scale (about 3 arcsec = 250 pc) is about a half of galaxy's effective radius, and its metallicity is 0.1-0.2 dex larger than the underlying population. Fitting the spectra with synthetic single stellar populations (SSP) we found an SSP-equivalent age of 5 Gyr and nearly solar metallicity [Fe/H]=-0.06 dex. We checked that these determinations are consistent with those based on Lick indices, but have smaller error bars. The kinematical discovery of a stellar disc in dE gives additional support to an evolutionary link from dwarf irregular galaxies due to stripping of the gas against the intra-cluster medium., 15 pages, 10 figures, accepted to MNRAS

Published
2007
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130. Molecular gas in NUclei of GAlaxies (NUGA): VI. Detection of a molecular gas disk/torus via HCN in the Seyfert 2 galaxy NGC 6951?

Author

L. K. Hunt, Linda J. Tacconi, M. Krips, Francoise Combes, Santiago García-Burillo, Eva Schinnerer, Frederic Boone, Stephane Leon, Andreas Eckart, Andrew J. Baker, R. Neri, Harvard-Smithsonian Center for Astrophysics, Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Observatorio Astronomico Nacional, Madrid, 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Max-Planck-Institut für Astronomie (MPIA), Department of Physics and Astronomy, State University of New Jersey, Physikalisches Institut, Universität zu Köln, Istituto di Radioastronomia, Firenze, Instituto de Radio Astronomía Milimétrica (IRAM), and Max-Planck-Institut für Extraterrestriche Physik (MPE)

Subjects
Physics, Active galactic nucleus, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Torus, Astrophysics, Radiation, Nuclear activity, Galaxy, medicine.anatomical_structure, [SDU]Sciences of the Universe [physics], Space and Planetary Science, medicine, Angular resolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Nucleus, Excitation
Abstract

Several studies of nearby active galaxies indicate significantly higher HCN-to-CO intensity ratios in AGN than in starburst (SB) environments. HCN enhancement can be caused by many different effects, such as higher gas densities/temperatures, UV/X-ray radiation, and non-collisional excitation. As active galaxies often exhibit intense circumnuclear SB, high angular resolution/sensitivity observations are of paramount importance to disentangling the influence of SB from that of nuclear activity on the chemistry of the surrounding molecular gas. The tight relation of HCN enhancement and nuclear activity may qualify HCN as an ideal tracer of molecular gas close to the AGN, providing complementary and additional information to that gained via CO. NGC6951 houses nuclear and SB activity, making it an ideal testbed in which to study the effects of different excitation conditions on the molecular gas. We used the new ABCD configurations of the IRAM PdBI to observe HCN(1-0) in NGC6951 at high angular resolution (1''). We detect very compact (0.4) in the nucleus than in the SB ring (0.02-0.05). As for NGC1068, this might result from a higher HCN abundance in the centre due to an X-ray dominated gas chemistry, but a higher gas density/temperature or additional non-collisional excitation of HCN cannot be entirely ruled out, based on these observations. The compact HCN emission is associated with rotating gas in a circumnuclear disk/torus., Letter accepted for publication in a special issue of A&A presenting results of the new extended configuration at the IRAM PdBI, to appear most likely around June 2007. Letter has 4 pages and 2 figures. Abstract has been shortened to meet the line limits of astrop-ph

Published
2007
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131. PHIBSS: Unified Scaling Relations of Gas Depletion Time and Molecular Gas Fractions

Author

Achim Weiss, Thorsten Naab, Chiara Feruglio, H. Übler, Fabian Walter, Frédéric Boone, Jonathan Freundlich, Thierry Contini, Alberto D. Bolatto, Amélie Saintonge, Simon J. Lilly, Amiel Sternberg, Stéphanie Juneau, Reinhard Genzel, Jérémie Boissier, Stijn Wuyts, Roberto Neri, Linda J. Tacconi, Andreas Burkert, Francoise Combes, Dieter Lutz, Pierre Cox, Magdalena Lippa, Benjamin J. Weiner, Gioacchino Accurso, Michael C. Cooper, M. Carollo, Rodrigo Herrera-Camus, Frédéric Bournaud, N. M. Förster Schreiber, P. Salome, Alvio Renzini, Santiago García-Burillo, Ken-ichi Tadaki, Nicolas Bouché, Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, AUTRES, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Collège de France - Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Observatorio Astronomico Nacional, Madrid, Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Institut de recherche en astrophysique et planétologie (IRAP), 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), Max-Planck-Institut für Extraterrestrische Physik (MPE), Laboratoire Nanotechnologies Nanosystèmes (LN2 ), Université de Sherbrooke (UdeS)-École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institute for Astronomy [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Max Planck Institute for Astrophysics, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Astronomie (MPIA), Steward observatory, University of Arizona, 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), Observatorio Astronomico Nacional [Madrid] (OAN), Instituto Geografico Nacional (IGN), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Interactions Hôtes-Pathogènes-Environnements (IHPE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Perpignan Via Domitia (UPVD), Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke [Sherbrooke], Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Universitätssternwarte der Ludwig-Maximiliansuniversität, Ludwig-Maximiliansuniversität, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), University of São Paulo, INAF - Osservatorio Astronomico di Roma (OAR), Istituto Nazionale di Astrofisica (INAF), Racah Institute of Physics, The Hebrew University of Jerusalem (HUJ), Institut of Physics - Riga, Latvian Academy of Sciences, Versuchsanstalt für Wasserbau, Hydrologie und Glaziologie (VAW), University of Edinburgh, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Chaire Galaxies et cosmologie, Observatorio Astronómico Nacional (OAN), oan, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Sherbrooke (UdeS)-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
Initial mass function, Stellar mass, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, galaxies [infrared], 0103 physical sciences, kinematics and dynamics [galaxies], Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Scaling, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, evolution [galaxies], Physics, Luminous infrared galaxy, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Gas depletion, Star formation, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Redshift, Galaxy, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, high-redshift [galaxies]
Abstract

This paper provides an update of our previous scaling relations (Genzel et al.2015) between galaxy integrated molecular gas masses, stellar masses and star formation rates, in the framework of the star formation main-sequence (MS), with the main goal to test for possible systematic effects. For this purpose our new study combines three independent methods of determining molecular gas masses from CO line fluxes, far-infrared dust spectral energy distributions, and ~1mm dust photometry, in a large sample of 1444 star forming galaxies (SFGs) between z=0 and 4. The sample covers the stellar mass range log(M*/M_solar)=9.0-11.8, and star formation rates relative to that on the MS, delta_MS=SFR/SFR(MS), from 10^{-1.3} to 10^{2.2}. Our most important finding is that all data sets, despite the different techniques and analysis methods used, follow the same scaling trends, once method-to-method zero point offsets are minimized and uncertainties are properly taken into account. The molecular gas depletion time t_depl, defined as the ratio of molecular gas mass to star formation rate, scales as (1+z)^{-0.6}x(delta_MS)^{-0.44}, and is only weakly dependent on stellar mass. The ratio of molecular-to-stellar mass mu_gas depends on (1+z)^{2.5}x (delta_MS)^{0.52}x(M*)^{-0.36}, which tracks the evolution of the specific star formation rate. The redshift dependence of mu_gas requires a curvature term, as may the mass-dependences of t_depl and mu_gas. We find no or only weak correlations of t_depl and mu_gas with optical size R or surface density once one removes the above scalings, but we caution that optical sizes may not be appropriate for the high gas and dust columns at high-z., Comment: Now accepted by ApJ; Figures and tables have been updated, and an appendix has been added

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132. ALMA imaging of C2H emission in the disk of NGC1068

Author

M. Krips, Francoise Combes, L. K. Hunt, C. Ramos Almeida, A. Fuente, M. Querejeta, Linda J. Tacconi, S. Martin, R. Aladro, S. Viti, Viviana Casasola, A. Usero, R. Neri, Santiago García-Burillo, P. van der Werf, Francesco Costagliola, Susanne Aalto, A. Alonso-Herrero, Carsten Henkel, Observatorio Astronomico Nacional [Madrid] (OAN), Instituto Geografico Nacional (IGN), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), 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), Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Observatorio Astronómico Nacional (OAN), oan, Laboratoire de Biophotonique et Pharmacologie - UMR 7213 (LBP), Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA)), Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Chalmers University of Technology [Göteborg], European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Istituto Nazionale di Astrofisica (INAF), Institut für Physik (Institut für Physik), Universität Potsdam, Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Observatorio Astronomico Nacional, Madrid, École normale supérieure - Paris (ENS-PSL), Collège de France - Chaire Galaxies et cosmologie, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS), University of Potsdam = Universität Potsdam, Universiteit Leiden, and ESP

Subjects
Physics, [PHYS]Physics [physics], Chemical models, 010308 nuclear & particles physics, Star formation, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Nuclear activity, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy, Barred spiral galaxy, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Outflow, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Multiplet, Hyperfine structure, ComputingMilieux_MISCELLANEOUS
Abstract

We study the feedback of star formation and nuclear activity on the chemistry of molecular gas in NGC1068, a nearby (D=14Mpc) Seyfert 2 barred galaxy, by analyzing if the abundances of key molecular species like ethynyl (C2H), a classical tracer of PDR, change in the different environments of the disk of the galaxy. We have used ALMA to map the emission of the hyperfine multiplet of C2H(N=1-0) and its underlying continuum emission in the central r~35"(2.5kpc)-region of the disk of NGC1068 with a spatial resolution 1.0"x0.7"(50-70pc). We have developed a set of time-dependent chemical models to determine the origin of the C2H gas. A sizeable fraction of the total C2H line emission is detected from the r~1.3kpc starburst (SB) ring. However, the brightest C2H emission originates from a r~200pc off-centered circumnuclear disk (CND), where evidence of a molecular outflow has been previously found in other molecular tracers imaged by ALMA. We also detect significant emission that connects the CND with the outer disk. We derived the fractional abundances of C2H (X(C2H)) assuming LTE conditions. Our estimates range from X(C2H)~a few 10^-8 in the SB ring up to X(C2H)~ a few 10^-7 in the outflow region. PDR models that incorporate gas-grain chemistry are able to account for X(C2H) in the SB ring for moderately dense (n(H2)>10^4 cm^-3) and moderately UV-irradiated gas (UV-field10^4-10^5) cm^-3). We interpret that the transient conditions required to fit the high values of X(C2H) in the outflow are likely due to UV/X-ray irradiated non-dissociative shocks associated with the highly turbulent interface between the outflow and the molecular gas in NGC1068., A&A accepted, 14 pages, 7 figures, 6 Tables

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133. Luminous, pc-scale CO 6-5 emission in the obscured nucleus of NGC1377

Author

P. van der Werf, S. Martin, Francesco Costagliola, Santiago García-Burillo, Kazushi Sakamoto, J. S. Gallagher, Sebastien Muller, Kalliopi Dasyra, Jari Kotilainen, Aaron S. Evans, Lars E. Kristensen, N. Falstad, Keiichi Wada, Francoise Combes, Sabine König, Susanne Aalto, Chalmers University of Technology [Göteborg], General Electric Medical Systems [Buc] (GE Healthcare), General Electric Medical Systems, Academia Sinica, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'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), Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Observatorio Astronomico Nacional [Madrid] (OAN), Instituto Geografico Nacional (IGN), Danish Meat Research Institute (DMRI), Laboratoire de Biophotonique et Pharmacologie - UMR 7213 (LBP), Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA)), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], 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 de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Collège de France - Chaire Galaxies et cosmologie, Observatorio Astronomico Nacional, Madrid, and Universiteit Leiden

Subjects
Active galactic nucleus, Astrophysics::High Energy Astrophysical Phenomena, nuclei [galaxies], FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, 0103 physical sciences, 010303 astronomy & astrophysics, molecules [ISM], Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, individual: NGC 1377 [galaxies], Physics, [PHYS]Physics [physics], Supermassive black hole, ISM [galaxies], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], jets and outflows [ISM], 010308 nuclear & particles physics, Star formation, Astronomy and Astrophysics, Torus, Position angle, Astrophysics - Astrophysics of Galaxies, Galaxy, Full width at half maximum, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), active [galaxies], Outflow, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

High resolution submm observations are important in probing the morphology, column density and dynamics of obscured active galactic nuclei (AGNs). With high resolution (0.06 x 0.05) ALMA 690 GHz observations we have found bright (TB >80 K) and compact (FWHM 10x7 pc) CO 6-5 line emission in the nucleus of the extremely radio-quiet galaxy NGC1377. The integrated CO 6-5 intensity is aligned with the previously discovered jet/outflow of NGC1377 and is tracing the dense (n>1e4 cm-3), hot gas at the base of the outflow. The velocity structure is complex and shifts across the jet/outflow are discussed in terms of jet-rotation or separate, overlapping kinematical components. High velocity gas (deltaV +-145 km/s) is detected inside r, 7 pages, 5 figures, submitted to Astronomy and Astrophysics

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134. The internal dynamics of the Local Group dwarf elliptical galaxies NGC 147, 185 and 205

Author

S. De Rijcke, P. Prugniel, Herwig Dejonghe, F. Simien, Sterrenkundig Observatorium, Universiteit Gent, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de 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), Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Astrophysics (astro-ph), Dark matter, FOS: Physical sciences, Velocity dispersion, Local Group, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Radius, Galaxy, Flattening, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Globular cluster, Elliptical galaxy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract

We present three-integral dynamical models for the three Local Group dwarf elliptical galaxies: NGC147, NGC185, and NGC205. It is the first time models are constructed for the Local Group dEs that allow for the presence of dark matter at large radii and that are constrained by kinematics out to at least one half-light radius. The B-band mass-to-light ratios of all three galaxies are rather similar, (M/L)_B = 3-4. Within the inner two half-light radii, about 40-50% of the mass is in the form of dark matter, so dEs contain about as much dark matter as bright ellipticals. NGC205 and NGC147 have a relatively isotropic velocity dispersion tensor within the region where the internal dynamics are strongly constrained by the data. Our estimated inclination for NGC185 is i ~ 50 degrees because in that case the model has an intrinsic flattening close to the peak of the intrinsic shape distribution of dEs and it, like the best fitting models for NGC147 and NGC205, is nearly isotropic. We also show that the dynamical properties of the bright nucleus of NGC205 are not unlike those of a massive globular cluster., Accepted for publication in MNRAS, 14 pages, 13 figures

Published
2006
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135. Improved 3D Fabry–Perot data reduction techniques*

Author

Philippe Amram, Olivier Daigle, Claude Carignan, L. Chemin, Olivier Hernandez, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Laboratoire d'Astrophysique Expérimentale (LAE), Observatoire du Mont Mégantic, Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Beaussier, Catherine, and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, 010308 nuclear & particles physics, media_common.quotation_subject, Astrophysics (astro-ph), Subtraction, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Signal, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Data cube, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Space and Planetary Science, Sky, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Algorithm, Fabry–Pérot interferometer, Beam (structure), Smoothing, Data reduction, media_common
Abstract

Improved data reduction techniques for 3D data cubes obtained from Fabry-Perot integral field spectroscopy are presented. They provide accurate sky emission subtraction and adaptive spatial binning and smoothing. They help avoiding the effect analogous to the beam smearing, seen in HI radio data, when strong smoothing is applied to 3D data in order to get the most extended signal coverage. The data reduction techniques presented in this paper allow one to get the best of both worlds: high spatial resolution in high signal-to-noise regions and large spatial coverage in low signal-to-noise regions., 10 pages, 9 figures, accepted for publication in MNRAS

Published
2006
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136. FALCON: multi-object AO

Author

Fanny Chemla, Jean-Marc Conan, F. Assemat, Norbert Hubin, Philippe Laporte, Frederic Zamkotsian, Michel Marteaud, M. Puech, Thierry Fusco, Pascal Jagourel, Eric Gendron, Francois Hammer, Arnaud Liotard, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Pôle instrumental, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Astronomie du LESIA, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Ingénieurs, Techniciens et Administratifs, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), and European Southern Observatory (ESO)

Subjects
Wavefront, Physics, business.industry, media_common.quotation_subject, Astrophysics::Instrumentation and Methods for Astrophysics, General Engineering, Energy Engineering and Power Technology, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy, Stars, Integral field spectrograph, Optics, Sky, Galaxy formation and evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Adaptive optics, Falcon, business, computer, Astrophysics::Galaxy Astrophysics, media_common, computer.programming_language
Abstract

International audience; FALCON is a wide-field, multi-object integral field spectrograph equipped with adaptive optics. It is dedicated to the study of the formation process of primordial galaxies. The AO system uses natural guide stars, and the high sky coverage required for these studies is obtained using tomographic techniques for the wavefront analysis. The structure of the OA system is very new, and particularly suited for a future implementation on extremely large telescopes. To cite this article: E. Gendron et al., C. R. Physique 6 (2005).

Published
2005
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137. Molecular gas in NUclei of GAlaxies (NUGA)

Author

Frédéric Boone, Leslie K. Hunt, Santiago García-Burillo, Eva Schinnerer, Francoise Combes, Observatorio Astronomico Nacional, Madrid, 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Institut für Radioastronomie (MPIfR), and Istituto di Radioastronomia, Firenze

Subjects
Physics, Gravity (chemistry), Angular momentum, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Inflow, Galaxy, Luminosity, Gravitation, Viscosity, Space and Planetary Science, Density contrast, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract

We discuss the efficiency of stellar gravity torques as a mechanism to account for the feeding of the central engines of four low luminosity AGN: NGC4321, NGC4826, NGC4579 and NGC6951. These galaxies have been observed as part of the NUGA CO project, aimed at the study of AGN fueling mechanisms. Our calculations allow us to derive the characteristic time-scales for gas flows and discuss whether torques from the stellar potentials are efficient enough to drain the gas angular momentum in the inner 1 kpc of these galaxies. Results indicate paradoxically that feeding should be thwarted close to the AGN: in the four cases analyzed, gravity torques are mostly positive inside r~200pc, resulting in no inflow on these scales. As a possible solution for the paradox, we speculate that the agent responsible for driving inflow to still smaller radii is transient and thus presently absent in the stellar potential. Alternatively, the gravity torque barrier associated with the ILR of the bars in these galaxies could be overcome by other mechanisms that become competitive in due time against gravity torques. We find that viscosity can counteract moderate--to--low gravity torques on the gas if it acts on a nuclear ring of high gas surface density contrast and a few 100pc size. We propose an evolutionary scenario in which gravity torques and viscosity act in concert to produce recurrent episodes of activity during the typical lifetime of any galaxy. In this scenario the recurrence of activity in galaxies is indirectly related to that of the bar instabilities., Comment: Accepted in Astronomy and Astrophysics, 24/06/05

Published
2005
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138. Spectral and morphological properties of quasar hosts in smoothed particle hydrodynamics simulations of active galactic nucleus feeding by mergers

Author

A. Cattaneo, F. Combes, S. Colombi, E. Bertin, A.-L. Melchior, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Astrophysikalisches Institut Potsdam (AIP), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Stellar population, Astrophysics::High Energy Astrophysical Phenomena, Astronomy and Astrophysics, Quasar, Torus, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy merger, Galaxy, Luminosity, Space and Planetary Science, Elliptical galaxy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, Optical depth
Abstract

We present a method for generating virtual observations from smoothed-particlehydrodynamics (SPH) simulations. This method includes stellar population synthesis models and the reprocessing of starlight by dust to produce realistic galaxy images. We apply this method and simulate the merging of two identical giant Sa galaxies (Mdisc = 10 11 M⊙, Mspheroid = 2.5 × 10 10 M⊙). The merger remnant is an elliptical galaxy (Mspheroid ≃ 1.3 × 10 11 M⊙, Mdisc ≃ 7.4 × 10 10 M⊙). The merger concentrates the gas content of the two galaxies into the nuclear region. The gas that flows into the nuclear region refuels the central black holes of the merging galaxies. We follow the refuelling of the black holes during the merger semi-analytically. In the simulation presented in this article, the black holes grow from 3 × 10 7 M⊙ to 1.8 × 10 8 M⊙, with a peak AGN luminosity of MB ∼ −23.7. We study how the morphological and spectral properties of the system evolve during the merger and work out the predictions of this scenario for the properties of host galaxies during the active phase. The peak of AGN activity coincides with the merging of the two galactic nuclei and occurs at a stage when the remnant looks like a lenticular galaxy. The simulation predicts the formation of a circumnuclear starburst ring/dusty torus with an opening angle of 30 ◦ − 40 ◦ and made of clouds with nH = 10 24 cm −2 . The average optical depth of the torus is quite high, but the obscuring medium is patchy, so that there still exist lines of sight where the AGN is visible in a nearly edge-on view. For the same reason, there are lines of sight where the AGN is completely obscured in the face-on view.

Published
2005
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139. A method for determining radio continuum spectra and its application to large surveys

Author

E. Davoust, W. van Driel, Françoise Genova, Bernd Vollmer, François Ochsenbein, Pascal Dubois, Laboratoire Gemini (LG), 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)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Radioastronomie (MPIfR), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), 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), Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Spectral index, Mean squared error, Astrophysics (astro-ph), Continuum (design consultancy), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Spectral line, Variable (computer science), [SDU]Sciences of the Universe [physics], Space and Planetary Science, Code (cryptography), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Remote sensing
Abstract

A new tool to extract cross-identifications and radio continuum spectra from radio catalogues contained in the VIZIER database of the CDS is presented. The code can handle radio surveys at different frequencies with different resolutions. It has been applied to 22 survey catalogues at 11 different frequencies containing a total of 3.5 million sources, which resulted in over 700000 independent radio cross-identifications and ~67000 independent radio spectra with more than two frequency points. A validation of the code has been performed using independent radio cross-correlations from the literature. The mean error of the determined spectral index is +-0.3. The code produces an output of variable format that can easily be adapted to the purpose of the user., Comment: 11 pages, 11 figures. Accepted for publication in A&A

Published
2005
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140. Spectroscopy of clusters in the ESO Distant Cluster Survey (EDisCS)

Author

Alfonso Aragón-Salamanca, Bo Milvang-Jensen, R. Pello, C. Halliday, Luc Simard, Bianca M. Poggianti, G. De Lucia, Roberto P. Saglia, G. Rudnick, Simon D. M. White, P. Jablonka, S. Poirier, Julianne J. Dalcanton, D. Clowe, Dennis Zaritsky, INAF-Osservatorio Astronomico di Padova, Max-Planck-Institut für Extraterrestriche Physik (MPE), Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), School of Physics and Astronomy, University of Nottingham, Max-Planck-Institut für Astrophysik (MPA), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), 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 Canada (NRC), Rheinische Friedrich-Wilhelms-Universität Bonn, Department of Astronomy [Seattle], University of Washington [Seattle], and Steward Observatory, University of Arizona

Subjects
Physics, Velocity dispersion, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy, Redshift, Space and Planetary Science, Cluster (physics), Galaxy formation and evolution, Substructure, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Spectroscopy, Astrophysics::Galaxy Astrophysics, Data reduction
Abstract

International audience; We present spectroscopic observations of galaxies in 4 clusters at z = 0.7-0.8 and in one cluster at z ˜ 0.5 obtained with the FORS2 spectrograph on the VLT as part of the ESO Distant Cluster Survey (EDisCS), a photometric and spectroscopic survey of 20 intermediate to high redshift clusters. We describe our target selection, mask design, observation and data reduction procedures, using these first 5 clusters to demonstrate how our strategies maximise the number of cluster members for which we obtain spectroscopy. We present catalogues containing positions, I-band magnitudes and spectroscopic redshifts for galaxies in the fields of our 5 clusters. These contain 236 cluster members, with the number of members per cluster ranging from 30 to 67. Our spectroscopic success rate, i.e. the fraction of spectroscopic targets which are cluster members, averages 50% and ranges from 30% to 75%. We use a robust biweight estimator to measure cluster velocity dispersions from our spectroscopic redshift samples. We also make a first assessment of substructure within our clusters. The velocity dispersions range from 400 to 1100 km s-1. Some of the redshift distributions are significantly non-Gaussian and we find evidence for significant substructure in two clusters, one at z ˜ 0.79 and the other at z ˜ 0.54. Both have velocity dispersions exceeding 1000 km s-1 but are clearly not fully virialised; their velocity dispersions may thus be a poor indicator of their masses. The properties of these first 5 EDisCS clusters span a wide range in redshift, velocity dispersion, richness and substructure, but are representative of the sample as a whole. Spectroscopy for the full dataset will allow a comprehensive study of galaxy evolution as a function of cluster environment and redshift.

Published
2004
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141. HST/WFPC2 morphologies and color maps of distant luminous infrared galaxies

Author

Hector Flores, X. Z. Zheng, Francois Hammer, Francois Assemat, D. Pelat, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Pôle instrumental, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Astronomie du LESIA, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Laboratoire Univers et Théories (LUTH (UMR_8102))

Subjects
Luminous infrared galaxy, Physics, Solar mass, Stellar mass, Pixel, Star formation, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy, Stars, Space and Planetary Science, Bulge, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract

Using HST/WFPC2 imaging in F606W (or F450W) and F814W filters, we obtained the color maps in observed frame for 36 distant (0.4, Comment: 20 pages, 14 figures, accepted for publication in A&A

Published
2004
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142. Star formation rates of distant luminous infrared galaxies derived from Hα and IR luminosities

Author

C. J. Cesarsky, D. Fadda, Hector Flores, F. Hammer, Yun-Feng Liang, Nicolas Gruel, D. Elbaz, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Southern Observatory (ESO), and Instituto de Astrofísica de Canarias (IAC)

Subjects
Luminous infrared galaxy, Physics, Star formation, Astrophysics (astro-ph), Extinction (astronomy), FOS: Physical sciences, Balmer series, Astronomy and Astrophysics, Astrophysics, Spectral line, Galaxy, Luminosity, symbols.namesake, Space and Planetary Science, symbols, Emission spectrum, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

We present a study of the star formation rate (SFR) for a sample of 16 distant galaxies detected by ISOCAM at 15um in the CFRS0300+00 and CFRS1400+52 fields. Their high quality and intermediate resolution VLT/FORS spectra have allowed a proper correction of the Balmer emission lines from the underlying absorption. Extinction estimates using the Hbeta/Hgamma and the Halpha/Hbeta Balmer decrement are in excellent agreement, providing a robust measurement of the instantaneous SFR based on the extinction-corrected Halpha luminosity. Star formation has also been estimated exploiting the correlations between IR luminosity and those at MIR and radio wavelengths. Our study shows that the relationship between the two SFR estimates follow two distinct regimes: (1) for galaxies with SFRIR below ~ 100Msolar/yr, the SFR deduced from Halpha measurements is a good approximation of the global SFR and (2) for galaxies near of ULIRGs regime, corrected Halpha SFR understimated the SFR by a factor of 1.5 to 2. Our analyses suggest that heavily extincted regions completely hidden in optical bands (such as those found in Arp 220) contribute to less than 20% of the global budget of star formation history up to z=1., Comment: (1) GEPI, Obs. Meudon, France ;(2) CEA-Saclay, France ;(3) ESO, Gemany ;(4) IAC, Spain. To appear in A&A

Published
2004
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143. Dynamical Effects of Interactions and the Tully-Fisher Relation for Hickson Compact Groups

Author

P. Amram, C. Mendes de Oliveira, Chantal Balkowski, Henri Plana, Departamento de Astronomia Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidade Estadual de Santa Cruz, Departamento Ciencias Exatas e Tecnologicas, Rodovia Ilheus-Itabuna, km. 16, 45650-000, Ilheus, BA, Brazil., Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Star formation, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Tully–Fisher relation, Galaxy, Dark matter halo, Compact group, Space and Planetary Science, Peculiar velocity, Halo, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, Galaxy rotation curve
Abstract

We investigate the properties of the B-band Tully-Fisher (T-F) relation for 25 compact group galaxies, using Vmax derived from 2-D velocity maps. Our main result is that the majority of the Hickson Compact Group galaxies lie on the T-F relation. However, about 20% of the galaxies, including the lowest-mass systems, have higher B luminosities for a given mass, or alternatively, a mass which is too low for their luminosities. We favour a scenario in which outliers have been brightened due to either enhanced star formation or merging. Alternatively, the T-F outliers may have undergone truncation of their dark halo due to interactions. It is possible that in some cases, both effects contribute. The fact that the B-band T-F relation is similar for compact group and field galaxies tells us that these galaxies show common mass-to-size relations and that the halos of compact group galaxies have not been significantly stripped inside R25. We find that 75% of the compact group galaxies studied (22 out of 29) have highly peculiar velocity fields. Nevertheless, a careful choice of inclination, position angle and center, obtained from the velocity field, and an average of the velocities over a large sector of the galaxy enabled the determination of fairly well-behaved rotation curves for the galaxies. However, two of the compact group galaxies which are the most massive members in M51--like pairs, HCG 91a and HCG 96a, have very asymmetric rotation curves, with one arm rising and the other one falling, indicating, most probably, a recent perturbation by the small close companions., 15 pages, 4 figures, accepted for publication in the Astronomical Journal

Published
2003
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144. Gas kinematics of a sample of five Hickson Compact Groups

Author

P. Amram, Henri Plana, C. Mendes de Oliveira, Chantal Balkowski, J. Boulesteix, Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatorio Nacional MCT, Rua General Jose Cristino 77, Sao Cristovao, 20921-400 Rio de Janeiro, RJ, Brazil, Departamento de Astronomia Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Space and Planetary Science, Continuum (design consultancy), Elliptical galaxy, Astronomy and Astrophysics, Astrophysics, Kinematics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Galaxy rotation curve, Galaxy
Abstract

International audience; We present Fabry Perot observations of galaxies in five Hickson Compact Groups: HCG 10, HCG 19, HCG 87, HCG 91 and HCG 96. We observed a total of 15 galaxies and we have detected ionized gas for 13 of them. We were able to derive 2D velocity, monochromatic, continuum maps and rotation curves for the 13 objects. Almost all galaxies in this study are late-type systems; only HCG 19a is an elliptical galaxy. We can see a trend of kinematic evolution within a group and among different groups - from strongly interacting systems to galaxies with no signs of interaction - HCG 10 exhibits at least one galaxy strongly disturbed; HCG 19 seems to be quite evolved; HCG 87 does not show any sign of merging but a possible gas exchange between two galaxies; HCG 91 could be accreting a new intruder; HCG 96 exhibits past and present interactions.

Published
2003
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145. Non-confirmation of reported $\ion{H}{I}$ clouds without optical counterparts in the Hercules cluster

Author

P. Papaderos, C. Balkowski, José M. Vílchez, V. Cayatte, Trinh X. Thuan, John M. Dickey, W. van Driel, H. Hernández, Karen O'Neil, Pierre-Alain Duc, Jorge Iglesias-Páramo, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Arecibo Observatory, Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Department of Astronomy, University of Minnesota, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Sternwarte Weinheim, Instituto de Astrofisica de Andalucia, CSIC (IAA), and Astronomy Department, University of Virginia, Charlottesville

Subjects
Physics, Gregorian telescope, Galactic astronomy, Continuum (measurement), 010308 nuclear & particles physics, media_common.quotation_subject, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, general, clusters, individual, Hercules cluster, galaxies, ISM, radio lines, 01 natural sciences, law.invention, Space and Planetary Science, law, Sky, 0103 physical sciences, Surface brightness, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, media_common
Abstract

21 cm HI line observations were made with the Arecibo Gregorian telescope of 9 HI clouds in the Hercules Cluster which were reported as tenative detections in a VLA HI study of the cluster (Dickey 1997) and for which our deep CCD imaging failed to find any optical counterparts. No sensitive observations could be made of one of these (sw-174) due to the presence of a close-by strong continuum source. The other 8 tentative HI detections were not reconfirmed by the Arecibo HI measurements. The CCD images did reveal faint, low surface brightness counterparts near the centres of two other VLA HI sources invisible on the Palomar Sky Survey, sw-103 and sw-194., Comment: 7 pages, accepted for Astronomy and Astrophysics on 8 Nov. 2002; new references added on 23 Dec. 2002

Published
2003
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146. HERSCHELEXTREME LENSING LINE OBSERVATIONS: [C ii] VARIATIONS IN GALAXIES AT REDSHIFTSz= 1–3

Author

Nicole P. H. Nesvadba, Casey Papovich, Jane R. Rigby, Pierre Guillard, Keely D. Finkelstein, Chris Carilli, Huan Yang, Karine Dassas, Steven L. Finkelstein, Francoise Combes, Sangeeta Malhotra, Michael A. Strauss, Min-Su Shin, Marco Spaans, James E. Rhoads, Maryvonne Gerin, Brenda Frye, National Radio Astronomy Observatory [Socorro] (NRAO), National Radio Astronomy Observatory (NRAO), 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), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Astronomy, School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, University of Texas, Austin, National Radio Astronomy Observatory, Socorro (NRAO), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Dynamique des milieux interstellaires et plasmas stellaires, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Steward Observatory, University of Arizona, NASA/Goddard Space Flight Center (NASA/GSFC), Oxford University, Kapteyn Astronomical Institute, University of Groningen, Department of Astrophysical Sciences, Princeton University, and George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics, Texas A&M University, College Station, TX 77843, USA

Subjects
ULTRALUMINOUS INFRARED GALAXIES, Infrared, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, ISM: atoms, PHOTODISSOCIATION REGIONS, Computer Science::Computational Geometry, 01 natural sciences, Luminosity, POLYCYCLIC AROMATIC-HYDROCARBONS, galaxies: high-redshift, 158 MU-M, 0103 physical sciences, STAR-FORMING GALAXIES, Astrophysics::Solar and Stellar Astrophysics, SIMILAR-TO 2.5, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, Line (formation), infrared: ISM, [PHYS]Physics [physics], Physics, INTERSTELLAR-MEDIUM, 010308 nuclear & particles physics, MIDINFRARED SPECTROSCOPY, Astronomy, Astronomy and Astrophysics, Photoelectric effect, VIRGO CLUSTER, Virgo Cluster, MOLECULAR GAS, Galaxy, Redshift, radiation mechanisms: thermal, Interstellar medium, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

We observed the [C II] line in 15 lensed galaxies at redshifts 1

Published
2017
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147. Simulating multiple merger pathways to the central kinematics of early-type galaxies

Author

G. S. Novak, Aaron J. Romanowsky, Joel R. Primack, Thomas J. Cox, Christopher E. Moody, Department of Physics, Le Conte Hall, University of California, Department of Physics and Astronomy [San Jose], San Jose State University [San Jose] (SJSU), Observatories of the Carnegie Institution of Washington, 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
Physics, Angular momentum, Spiral galaxy, 010308 nuclear & particles physics, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Mass ratio, Galaxy merger, 01 natural sciences, Specific relative angular momentum, Astrophysics - Astrophysics of Galaxies, Galaxy, Peculiar galaxy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Galaxy formation and evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Two-dimensional integral field surveys such as ATLAS^3D are producing rich observational data sets yielding insights into galaxy formation. These new kinematic observations have highlighted the need to understand the evolutionary mechanisms leading to a spectrum of fast-rotators and slow-rotators in early-type galaxies. We address the formation of slow and fast rotators through a series of controlled, comprehensive hydrodynamical simulations sampling idealized galaxy merger scenarios constructed from model spiral galaxies. Idealized and controlled simulations of this sort complement the more 'realistic' cosmological simulations by isolating and analyzing the effects of specific parameters, as we do in this paper. We recreate minor and major binary mergers, binary merger trees with multiple progenitors, and multiple sequential mergers. Within each of these categories of formation history, we correlate progenitor gas fraction, mass ratio, orbital pericenter, orbital ellipticity, and spin with remnant kinematic properties. We create kinematic profiles of these 95 simulations comparable to ATLAS^3D data. By constructing remnant profiles of the projected specific angular momentum (lambda_R = / , triaxiality, and measuring the incidences of kinematic twists and kinematically decoupled cores, we distinguish between varying formation scenarios. We find that binary mergers nearly always form fast rotators. Slow rotators can be formed from zero initial angular momentum configurations and gas-poor mergers, but are not as round as the ATLAS^3D galaxies. Remnants of binary merger trees are triaxial slow rotators. Sequential mergers form round slow rotators that most resemble the ATLAS^3D rotators., Comment: MNRAS, in press, 12 pages, 15 figures

Published
2014
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148. The role of turbulence in star formation laws and thresholds

Author

Florent Renaud, Eric Emsellem, Katarina Kraljic, Frédéric Bournaud, Francoise Combes, Bruce G. Elmegreen, Romain Teyssier, University of Zurich, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), IBM T. J. Watson Research Center, European Southern Observatory, D-85748 Garching bei Muenchen, Germany, Observatoire de Lyon, and Universität Bern [Bern] (UNIBE)

Subjects
530 Physics, Metallicity, Milky Way, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Parsec, 1912 Space and Planetary Science, 0103 physical sciences, Thermal, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Dwarf galaxy, Physics, 010308 nuclear & particles physics, Star formation, Turbulence, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 10231 Institute for Computational Science, 3103 Astronomy and Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

The Schmidt-Kennicutt relation links the surface densities of gas to the star formation rate in galaxies. The physical origin of this relation, and in particular its break, i.e. the transition between an inefficient regime at low gas surface densities and a main regime at higher densities, remains debated. Here, we study the physical origin of the star formation relations and breaks in several low-redshift galaxies, from dwarf irregulars to massive spirals. We use numerical simulations representative of the Milky Way, the Large and the Small Magellanic Clouds with parsec up to subparsec resolution, and which reproduce the observed star formation relations and the relative variations of the star formation thresholds. We analyze the role of interstellar turbulence, gas cooling, and geometry in drawing these relations, at 100 pc scale. We suggest in particular that the existence of a break in the Schmidt- Kennicutt relation could be linked to the transition from subsonic to supersonic turbulence and is independent of self-shielding effects. This transition being connected to the gas thermal properties and thus to the metallicity, the break is shifted toward high surface densities in metal-poor galaxies, as observed in dwarf galaxies. Our results suggest that together with the collapse of clouds under self-gravity, turbulence (injected at galactic scale) can induce the compression of gas and regulate star formation., Comment: 15 pages, 19 figures; accepted for publication in the Astrophysical Journal

Published
2014
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149. Molecular gas content in strongly-lensed z~1.5-3 star-forming galaxies with low IR luminosities

Author

Andrew Blain, T. Rawle, J. P. Kneib, Daniel Schaerer, A. M. Swinbank, M. Rex, Francoise Combes, J. Richard, Eiichi Egami, Frederic Boone, Panos Sklias, Miroslava Dessauges-Zavadsky, M. Zamojski, Observatoire de Genève, Institut de recherche en astrophysique et planétologie (IRAP), 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), Galaxies et cosmologie, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Steward Observatory, University of Arizona, Institute for Computational Cosmology, Department of Physics, Durham University, Durham (ICC), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de 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), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Ecole Polytechnique Federale de Lausanne (EPFL), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Department of Physics & Astronomy, University of Leicester

Subjects
Physics, Stellar mass, Gas depletion, Star formation, Infrared, Plateau de Bure Interferometer, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Redshift, Luminosity, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

To extend the molecular gas measurements to typical star-forming galaxies (SFGs) with SFR < 40 Msun yr^{-1} and M* < 2.5x10^{10} Msun at z~1.5-3, we have observed CO emission with the IRAM Plateau de Bure Interferometer and 30m telescope for five strongly-lensed galaxies selected from the Herschel Lensing Survey. These observations are combined with a compilation of CO measurements from the literature. We infer the luminosity correction factors r2,1 = 0.81+/-0.20 and r3,1 = 0.57+/-0.15 for the J=2 and J=3 CO transitions, respectively, valid for SFGs at z>1. The combined sample of CO-detected SFGs at z>1 shows a large spread in star formation efficiency (SFE), such that SFE extend beyond the low values of local spirals and overlap the distribution of z>1 sub-mm galaxies. We find that the spread in SFE (or equivalently in molecular gas depletion timescale) is due to primarily the specific star formation rate, but also stellar mass and redshift. Correlations of SFE with the offset from the main-sequence and the compactness of the starburst are less clear. The increase of the molecular gas depletion timescale with M* now revealed by low M* SFGs at z>1 and observed at z=0 is in contrast to the admitted constant molecular gas depletion timescale and the linear Kennicutt-Schmidt relation. We confirm an increase of the molecular gas fraction (fgas) from z~0.2 to z~1.2, followed by a very mild increase toward higher redshifts. At each redshift fgas shows a large dispersion due to the dependence of fgas on M*, producing a gradient of increasing fgas with decreasing M*. We provide the first measure of fgas of z>1 SFGs at the low-M* end (10^{9.4} < M*/Msun < 10^{9.9}), reaching a mean fgas = 0.69+/-0.18, which shows a clear fgas upturn. Finally, we find evidence for a non-universal dust-to-gas ratio among high-redshift SFGs and sub-mm galaxies, local spirals and ULIRGs with near-solar metallicities., 21 pages, 16 figures. Accepted in A&A

Published
2014
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150. The S4I prototype: a beam-slicer system dedicated to the new generation multichannel subtractive double pass for EST imaging spectropolarimetry

Author

Sayède, Frédéric, Mein, Pierre, Amans, Jean-Philippe, Moity, Jacques, Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Physique des Galaxies et Cosmologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Physique solaire, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris

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

International audience; For the future European Solar Telescope (EST) the Observatoire de Paris proposes a new generation of MSDP: an imaging spectro-polarimetry instrument. To validate this new generation, we develop a beam slicer prototype that will be tested and validated on an optical bench and on existing telescopes. The prototype called S4I (Spectral Sampling with Slicer for Solar Instrumentation) is under construction and tested at the Observatoire de Paris. It validates the opto-mechanical feasibility of the new beam slicer. The manufacture is now complete: we give a description of the whole system. We give also some results of the first tests.

Published
2012
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