181 results on '"Bournaud, F."'
Search Results
2. Starbursts with suppressed velocity dispersion revealed in a forming cluster at z & x2006;& x2004;=& x2004;& x2006;2.51
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Xiao, M. -Y., Wang, T., Elbaz, D., Iono, D., Lu, X., Bing, L. -J., Daddi, E., Magnelli, B., Gomez-Guijarro, C., Bournaud, F., Gu, Q. -S., Jin, S., Valentino, F., Zanella, A., Gobat, R., Martin, S., Brammer, G., Kohno, K., Schreiber, C., Ciesla, L., Yu, X. -L., and Okumura, K.
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DEPLETION TIME ,SPECTROSCOPIC SURVEY ,INTERSTELLAR-MEDIUM ,formation ,MASSIVE GALAXIES ,COSMIC STAR-FORMATION ,SCALING RELATIONS ,high-redshift ,general ,DUSTY STARBURSTS ,ROTATION CURVES ,galaxies ,evolution ,clusters ,MAIN-SEQUENCE ,MOLECULAR GAS MASSES ,ISM - Abstract
One of the most prominent features of galaxy clusters is the presence of a dominant population of massive ellipticals in their cores. Stellar archaeology suggests that these gigantic beasts assembled most of their stars in the early Universe via starbursts. However, the role of dense environments and their detailed physical mechanisms in triggering starburst activities remain unknown. Here we report spatially resolved Atacama Large Millimeter/submillimeter Array (ALMA) observations of the CO J & x2004;=& x2004;3-2 emission line, with a resolution of about 2.5 kpc, toward a forming galaxy cluster core with starburst galaxies at z & x2004;=& x2004;2.51. In contrast to starburst galaxies in the field often associated with galaxy mergers or highly turbulent gaseous disks, our observations show that the two starbursts in the cluster exhibit dynamically cold (rotation-dominated) gas-rich disks. Their gas disks have extremely low velocity dispersion (sigma(0)& x2004;similar to & x2004;20-30 km s(-1)), which is three times lower than their field counterparts at similar redshifts. The high gas fraction and suppressed velocity dispersion yield gravitationally unstable gas disks, which enables highly efficient star formation. The suppressed velocity dispersion, likely induced by the accretion of corotating and coplanar cold gas, might serve as an essential avenue to trigger starbursts in massive halos at high redshifts.
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- 2022
3. GOODS-ALMA 2.0 : starbursts in the main sequence reveal compact star formation regulating galaxy evolution prequenching
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Gómez-Guijarro, C., Elbaz, D., Xiao, M., Kokorev, V.I., Magdis, G.E., Magnelli, B., Daddi, E., Valentino, F., Sargent, M.T., Dickinson, M., Béthermin, M., Franco, M., Pope, A., Kalita, B.S., Ciesla, L., Demarco, R., Inami, H., Rujopakarn, W., Shu, X., Wang, T., Zhou, L., Alexander, D.M., Bournaud, F., Chary, R., Ferguson, H.C., Finkelstein, S.L., Giavalisco, M., Iono, D., Juneau, S., Kartaltepe, J.S., Lagache, G., Le Floc’h, E., Leiton, R., Leroy, L., Lin, L., Motohara, K., Mullaney, J., Okumura, K., Pannella, M., Papovich, C., and Treister, E.
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Compact star formation appears to be generally common in dusty star-forming galaxies (SFGs). However, its role in the framework set by the scaling relations in galaxy evolution remains to be understood. In this work we follow up on the galaxy sample from the GOODS-ALMA 2.0 survey, an ALMA blind survey at 1.1 mm covering a continuous area of 72.42 arcmin2 using two array configurations. We derived physical properties, such as star formation rates, gas fractions, depletion timescales, and dust temperatures for the galaxy sample built from the survey. There exists a subset of galaxies that exhibit starburst-like short depletion timescales, but they are located within the scatter of the so-called main sequence of SFGs. These are dubbed starbursts in the main sequence and display the most compact star formation and they are characterized by the shortest depletion timescales, lowest gas fractions, and highest dust temperatures of the galaxy sample, compared to typical SFGs at the same stellar mass and redshift. They are also very massive, accounting for ∼60% of the most massive galaxies in the sample (log(M*/M⊙) > 11.0). We find trends between the areas of the ongoing star formation regions and the derived physical properties for the sample, unveiling the role of compact star formation as a physical driver of these properties. Starbursts in the main sequence appear to be the extreme cases of these trends. We discuss possible scenarios of galaxy evolution to explain the results drawn from our galaxy sample. Our findings suggest that the star formation rate is sustained in SFGs by gas and star formation compression, keeping them within the main sequence even when their gas fractions are low and they are presumably on the way to quiescence.
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- 2022
4. GOODS-ALMA 2.0 : source catalog, number counts, and prevailing compact sizes in 1.1 mm galaxies
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Gómez-Guijarro, C., Elbaz, D., Xiao, M., Béthermin, M., Franco, M., Magnelli, B., Daddi, E., Dickinson, M., Demarco, R., Inami, H., Rujopakarn, W., Magdis, G.E., Shu, X., Chary, R., Zhou, L., Alexander, D.M., Bournaud, F., Ciesla, L., Ferguson, H.C., Finkelstein, S.L., Giavalisco, M., Iono, D., Juneau, S., Kartaltepe, J.S., Lagache, G., Le Floc’h, E., Leiton, R., Lin, L., Motohara, K., Mullaney, J., Okumura, K., Pannella, M., Papovich, C., Pope, A., Sargent, M.T., Silverman, J.D., Treister, E., and Wang, T.
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Submillimeter/millimeter observations of dusty star-forming galaxies with the Atacama Large Millimeter/submillimeter Array (ALMA) have shown that dust continuum emission generally occurs in compact regions smaller than the stellar distribution. However, it remains to be understood how systematic these findings are. Studies often lack homogeneity in the sample selection, target discontinuous areas with inhomogeneous sensitivities, and suffer from modest uv coverage coming from single array configurations. GOODS-ALMA is a 1.1 mm galaxy survey over a continuous area of 72.42 arcmin2 at a homogeneous sensitivity. In this version 2.0, we present a new low resolution dataset and its combination with the previous high resolution dataset from the survey, improving the uv coverage and sensitivity reaching an average of σ = 68.4 μJy beam−1. A total of 88 galaxies are detected in a blind search (compared to 35 in the high resolution dataset alone), 50% at S/Npeak ≥ 5 and 50% at 3.5 ≤ S/Npeak ≤ 5 aided by priors. Among them, 13 out of the 88 are optically dark or faint sources (H- or K-band dropouts). The sample dust continuum sizes at 1.1 mm are generally compact, with a median effective radius of Re = 0.″10 ± 0.″05 (a physical size of Re = 0.73 ± 0.29 kpc at the redshift of each source). Dust continuum sizes evolve with redshift and stellar mass resembling the trends of the stellar sizes measured at optical wavelengths, albeit a lower normalization compared to those of late-type galaxies. We conclude that for sources with flux densities S1.1 mm > 1 mJy, compact dust continuum emission at 1.1 mm prevails, and sizes as extended as typical star-forming stellar disks are rare. The S1.1 mm < 1 mJy sources appear slightly more extended at 1.1 mm, although they are still generally compact below the sizes of typical star-forming stellar disks.
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- 2022
5. Cosmic-ray diffusion and the multi-phase interstellar medium in a dwarf galaxy. I. Large-scale properties and $\gamma$-ray luminosities
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Nuñez-Castiñeyra, A., Grenier, I. A., Bournaud, F., Dubois, Y., Youssef, F. R. Kamal, Hennebelle, P., HEP, INSPIRE, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), and Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
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Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,[PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph] ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics - Abstract
International audience; Dynamically, cosmic rays with energies above about one GeV/nucleon may be important agents of galaxy evolution. Their pressures compare with the thermal and magnetic ones impacting galactic gas accretion, fountains and galactic outflows, and alter the mass cycling between the gas phases, its efficiency depends on the properties of CR transport in the different media. We aim to study the dynamical role of CRs in shaping the interstellar medium of a galaxy when changing their propagation mode. We perform MHD simulations with the AMR code RAMSES of the evolution of the same isolated galaxy (dwarf galaxy of $10^{11}$ M$_{\odot}$ down to 9-pc resolution) and compare the impact of the simplest cosmic-ray transport assumption of uniform diffusion. We have also updated the observational relation seen between the $\gamma$-ray luminosities and SFR of galaxies using the latest detection of Fermi LAT sources. We find that the radial and vertical distributions, and mass fractions of the gas in the different phases are marginally altered when changing CR transport. We observe positive feedback of CR on the amplification of the magnetic field in the inner half of the galaxy, except for fast isotropic diffusion. The increase in CR pressure for slow or anisotropic diffusion can suppress star formation by up to 50%, but the dual effect of cosmic-ray pressure and magnetic amplification can reduce star formation by a factor 2.5. The $\gamma$-ray luminosities and SFR of the simulated galaxies are fully consistent with the trend seen in the observations in the case of anisotropic $10^{27.5-29}$ cm$^2$ s$^{-1}$ diffusion and for isotropic diffusion slower or equal to $3 \times 10^{28}$cm$^2$ s$^{-1}$. These results, therefore, do not confirm claims of very fast $10^{29-31}$ cm$^2$ s$^{-1}$ diffusion to match the Fermi LAT observations.
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- 2022
6. An extremely young massive clump forming by gravitational collapse in a primordial galaxy
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Zanella, A., Daddi, E., Floch, E. Le, Bournaud, F., Gobat, R., Valentino, F., Strazzullo, V., Cibinel, A., Onodera, M., Perret, V., Renaud, F., and Vignali, C.
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Gravity -- Observations ,Star formation -- Observations ,Galaxies -- Observations ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
When cosmic star formation history reaches a peak (at about redshift z ≅ 2), galaxies vigorously fed by cosmic reservoirs (1,2) are dominated by gas (3,4) and contain massive star-forming clumps (5,6), which are thought to form by violent gravitational instabilities in highly turbulent gas-rich disks (7,8). However, a clump formation event has not yet been observed, and it is debated whether clumps can survive energetic feedback from young stars, and afterwards migrate inwards to form galaxy bulges (9-12). Here we report the spatially resolved spectroscopy of a bright off-nuclear emission line region in a galaxy at z = 1.987. Although this region dominates star formation in the galaxy disk, its stellar continuum remains undetected in deep imaging, revealing an extremely young (less than ten million years old) massive clump, forming through the gravitational collapse of more than one billion solar masses of gas. Gas consumption in this young clump is more than tenfold faster than in the host galaxy, displaying high star-formation efficiency during this phase, in agreement with our hydrodynamic simulations. The frequency of older clumps with similar masses (13), coupled with our initial estimate of their formation rate (about 2.5 per billion years), supports long lifetimes (about 500 million years), favouring models in which clumps survive feedback and grow the bulges of present-day galaxies., The high spatial resolution and sensitivity of Hubble Space Telescope (HST) imaging and spectroscopy routinely allows us to resolve giant star-forming regions (clumps) inside galaxies at z ≅ 2, at [...]
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- 2015
7. High molecular gas fractions in normal massive star-forming galaxies in the young Universe
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Tacconi, L.J., Genzel, R., Neri, R., Cox, P., Cooper, M.C., Shapiro, K., Bolatto, A., Bouche, N., Bournaud, F., Burkert, a., Combes, F., Comerford, J., Davis, M., Schreiber, N.M. Forster, Garcia-Burillo, S., Gracia-Carpio, J., Lutz, D., Naab, T., Omont, A., Shapley, A., Sternberg, A., and Weiner, B.
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Galaxies -- Spectra -- Observations ,Astronomy -- Spectra ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
Stars form from cold molecular interstellar gas. As this is relatively rare in the local Universe, galaxies like the Milky Way form only a few new stars per year. Typical massive galaxies in the distant Universe formed stars an order of magnitude more rapidly (1,2). Unless star formation was significantly more efficient, this difference suggests that young galaxies were much more molecular-gas rich. Molecular gas observations in the distant Universe have so far largely been restricted to very luminous, rare objects, including mergers and quasars (3-5), and accordingly we do not yet have a clear idea about the gas content of more normal (albeit massive) galaxies. Here we report the results of a survey of molecular gas in samples of typical massive-star-forming galaxies at mean redshifts of about 1.2 and 2.3, when the Universe was respectively 40% and 24% of its current age. Our measurements reveal that distant star forming galaxies were indeed gas rich, and that the star formation efficiency is not strongly dependent on cosmic epoch. The average fraction of cold gas relative to total galaxy baryonic mass at z = 2.3 and z = 1.2 is respectively about 44% and 34%, three to ten times higher than in today's massive spiral galaxies (6). The slow decrease between z ≅ 2 and z ≅ 1 probably requires a mechanism of semi-continuous replenishment of fresh gas to the young galaxies., Direct observations of molecular gas in galaxies as a function of cosmic epoch are required to understand how galaxies have turned their gas into stars. To explore the evolution of [...]
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- 2010
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8. NewHorizon simulation – to bar or not to bar.
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Reddish, J, Kraljic, K, Petersen, M S, Tep, K, Dubois, Y, Pichon, C, Peirani, S, Bournaud, F, Choi, H, Devriendt, J, Jackson, R, Martin, G, Park, M J, Volonteri, M, and Yi, S K
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DISK galaxies ,DARK matter ,GALACTIC bulges ,INSPECTION & review ,GALACTIC evolution ,STELLAR mass ,SPATIAL resolution - Abstract
We use the NewHorizon simulation to study the redshift evolution of bar properties and fractions within galaxies in the stellar masses range M
⋆ = 107.25 –1011.4 |$\, \rm {M}_\odot$| over the redshift range of z = 0.25–1.3. We select disc galaxies using stellar kinematics as a proxy for galaxy morphology. We employ two different automated bar detection methods, coupled with visual inspection, resulting in observable bar fractions of fbar = 0.070 |$_{{-0.012}}^{{+0.018}}$| at z ∼ 1.3, decreasing to fbar = 0.011 |$_{{-0.003}}^{{+0.014}}$| at z ∼ 0.25. Only one galaxy is visually confirmed as strongly barred in our sample. This bar is hosted by the most massive disc and only survives from z = 1.3 down to z = 0.7. Such a low bar fraction, in particular amongst Milky Way-like progenitors, highlights a missing bars problem, shared by literally all cosmological simulations with spatial resolution <100 pc to date. The analysis of linear growth rates, rotation curves, and derived summary statistics of the stellar, gas and dark matter components suggest that galaxies with stellar masses below 109.5 −1010 |$\, \rm {M}_\odot$| in NewHorizon appear to be too dominated by dark matter relative to stellar content to form a bar, while more massive galaxies typically have formed large bulges that prevent bar persistence at low redshift. This investigation confirms that the evolution of the bar fraction puts stringent constraints on the assembly history of baryons and dark matter on to galaxies. [ABSTRACT FROM AUTHOR]- Published
- 2022
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9. Large turbulent reservoirs of cold molecular gas around high-redshift starburst galaxies
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Falgarone, E., Zwaan, M. A., Godard, B., Bergin, E., Ivison, R. J., Andreani, P. M., Bournaud, F., Bussmann, R. S., Elbaz, D., Omont, A., Oteo, I., and Walter, F.
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Starburst galaxies -- Natural history ,Star formation -- Natural history ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
Author(s): E. Falgarone (corresponding author) [1]; M. A. Zwaan [2]; B. Godard [1]; E. Bergin [3]; R. J. Ivison [2, 4]; P. M. Andreani [2]; F. Bournaud [5]; R. S. [...]
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- 2017
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10. Evidence for Cold-stream to Hot-accretion Transition as Traced by Lyα Emission from Groups and Clusters at 2 < z < 3.3.
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Daddi, E., Rich, R. M., Valentino, F., Jin, S., Delvecchio, I., Liu, D., Strazzullo, V., Neill, J., Gobat, R., Finoguenov, A., Bournaud, F., Elbaz, D., Kalita, B. S., O'Sullivan, D., and Wang, T.
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- 2022
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11. PHIBSS2: survey design and z = 0.5 – 0.8 results
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Freundlich, J., Combes, F., Tacconi, L., Genzel, R., García-Burillo, S., Neri, R., Contini, T., Bolatto, A., Lilly, S., Salomé, P., Bicalho, I., Boissier, J., Boone, F., Bouché, N., Bournaud, F., Burkert, A., Carollo, M., Cooper, M., Cox, P., Feruglio, C., Schreiber, N, Juneau, S., Lippa, M., Lutz, D., Naab, T., Renzini, A., Saintonge, A., Sternberg, A., Walter, F., Weiner, B., Weiß, A., Wuyts, S., Racah Institute of Physics, The Hebrew University of Jerusalem (HUJ), 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)), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Observatorio Astronómico Nacional (OAN), oan, Institut de recherche en astrophysique et planétologie (IRAP), 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), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, AUTRES, Biologie et écologie tropicale et méditerranéenne [2007-2010] (BETM), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Nanotechnologies Nanosystèmes (LN2 ), 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), 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 (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), Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Universitätssternwarte der Ludwig-Maximiliansuniversität, Max-Planck-Institut für Extraterrestrische Physik (MPE), Institut of Physics - Riga, Latvian Academy of Sciences, Steward observatory, University of Arizona, 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), Collège de France - Chaire Galaxies et cosmologie, Observatorio Astronomico Nacional, Madrid, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE), 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]), 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), 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), 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], 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), Versuchsanstalt für Wasserbau, Hydrologie und Glaziologie (VAW), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Biologie et écologie tropicale et méditerranéenne (BETM), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Nanotechnologies Nanosystèmes (LN2), Université de Sherbrooke [Sherbrooke]-École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and 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 (UGA)
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[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,[SDU]Sciences of the Universe [physics] ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,ComputingMilieux_MISCELLANEOUS ,Astrophysics::Galaxy Astrophysics - Abstract
International audience; Following the success of the Plateau de Bure high-z Blue Sequence Survey (PHIBSS), we present the PHIBSS2 legacy program, a survey of the molecular gas properties of star-forming galaxies on and around the star-formation main sequence (MS) at different redshifts using IRAM's NOrthern Extended Millimeter Array (NOEMA). This survey significantly extends the existing sample of star-forming galaxies with CO molecular gas measurements, probing the peak epoch of star formation (z = 1 − 1.6) as well as its building-up (z = 2 − 3) and winding-down (z = 0.5 − 0.8) phases. The targets are drawn from the well-studied GOODS, COSMOS, and AEGIS cosmological deep fields and uniformly sample the MS in the stellar mass (M)-star formation rate (SFR) plane with log(M /M) = 10 − 11.8 and SFR = 3.5 − 500 M yr −1 without morphological selection, thus providing a statistically meaningful census of star-forming galaxies at different epochs. We describe the survey strategy and sample selection before focusing on the results obtained at redshift z = 0.5 − 0.8, where we report 60 CO(2-1) detections out of 61 targets. We determine molecular gas masses between 2 × 10 9 and 5 × 10 10 M and separately obtain disc sizes and bulge-to-total (B/T) luminosity ratios from HST I-band images. The median molecular gas-to-stellar mass ratio µ gas = 0.28 ± 0.04, gas fraction f gas = 0.22 ± 0.02, and depletion time t depl = 0.84 ± 0.07 Gyr as well as their dependence with stellar mass and offset from the MS follow published scaling relations for a much larger sample of galaxies spanning a significantly wider range of redshifts, the cosmic evolution of the SFR being mainly driven by that of the molecular gas fraction. The galaxy-averaged molecular Kennicutt-Schmidt (KS) relation between molecular gas and SFR surface densities is strikingly linear, pointing towards similar star formation timescales within galaxies at any given epoch. In terms of morphology, the molecular gas content, the SFR, the disc stellar mass, and the disc molecular gas fraction do not seem to correlate with B/T and the stellar surface density, which suggests an ongoing supply of fresh molecular gas to compensate for the build-up of the bulge. Our measurements do not yield any significant variation of the depletion time with B/T and hence no strong evidence for morphological quenching within the scatter of the MS.
- Published
- 2019
12. The [C ii] emission as a molecular gas mass tracer in galaxies at low and high redshifts
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Zanella, A., Daddi, Emanuele, Magdis, G., Diaz Santos, T., Cormier, D., Liu, D., Cibinel, A., Gobat, R., Dickinson, M., Sargent, M., Popping, G., Madden, S. C., Béthermin, M., Hughes, T. M., Valentino, F., Rujopakarn, W., Pannella, M., Bournaud, F., Walter, F., Wang, T., Elbaz, D., Coogan, R. T., Daddi, A, Diaz santos, A, Cormier, A, Liu, A, Gobat, A, Dickinson, A, Sargent, A, Popping, A., Madden, A, Bethermin, A, Hughes, A, Valentino, D, Rujopakarn, A, Pannella, G, Bournaud, A, Walter, A., Wang, A, Elbaz, A., Coogan, A, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), National Optical Astronomy Observatory (NOAO), 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), Sterrenkundig Observatorium, Universiteit Gent = Ghent University (UGENT), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, University of Strathclyde [Glasgow], Faculté de pharmacie, Université Louis Pasteur - Strasbourg I, 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), NOAO, 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), Universiteit Gent, and University of Strathclyde
- Subjects
galaxies: high redshift ,[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] ,Metallicity ,FOS: Physical sciences ,galaxies: starburst ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Computer Science::Computational Geometry ,01 natural sciences ,Luminosity ,TRACER ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,QB ,Physics ,010308 nuclear & particles physics ,Star formation ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Redshift ,Interstellar medium ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,galaxies: star formation ,[SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA] ,Spatial extent ,galaxies: evolution ,submillimetre: galaxies ,galaxies: ISM - Abstract
We present ALMA Band 9 observations of the [C II]158um emission for a sample of 10 main-sequence galaxies at redshift z ~ 2, with typical stellar masses (log M*/Msun ~ 10.0 - 10.9) and star formation rates (~ 35 - 115 Msun/yr). Given the strong and well understood evolution of the interstellar medium from the present to z = 2, we investigate the behaviour of the [C II] emission and empirically identify its primary driver. We detect [C II] from six galaxies (four secure, two tentative) and estimate ensemble averages including non detections. The [C II]-to-infrared luminosity ratio (L[C II]/LIR) of our sample is similar to that of local main-sequence galaxies (~ 2 x 10^-3), and ~ 10 times higher than that of starbursts. The [C II] emission has an average spatial extent of 4 - 7 kpc, consistent with the optical size. Complementing our sample with literature data, we find that the [C II] luminosity correlates with galaxies' molecular gas mass, with a mean absolute deviation of 0.2 dex and without evident systematics: the [C II]-to-H2 conversion factor (alpha_[C II] ~ 30 Msun/Lsun) is largely independent of galaxies' depletion time, metallicity, and redshift. [C II] seems therefore a convenient tracer to estimate galaxies' molecular gas content regardless of their starburst or main-sequence nature, and extending to metal-poor galaxies at low and high redshifts. The dearth of [C II] emission reported for z > 6 - 7 galaxies might suggest either a high star formation efficiency or a small fraction of UV light from star formation reprocessed by dust., Accepted for publication in MNRAS. 28 pages, including 12 figures, 5 tables, 3 appendices
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- 2018
13. An almost head-on collision as the origin of two off-centre rings in the Andromeda galaxy
- Author
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Block, D. L., Bournaud, F., Combes, F., Groess, R., Barmby, P., Ashby, M. L. N., Fazio, G. G., Pahre, M. A., and Willner, S. P.
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- 2006
14. The Dust and [C ii] Morphologies of Redshift ∼4.5 Sub-millimeter Galaxies at ∼200 pc Resolution:The Absence of Large Clumps in the Interstellar Medium at High-redshift
- Author
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Novak, Mladen, Sargent, Mark, Herrera-Camus, R., Belli, S., Übler, H., Shimizu, T., Davies, R., Sturm, E., Colina, L., Cunha, E. da, Rybak, M., Venemans, B., Brandt, W., Rivera, G. Calistro, Knudsen, K., Werf, P. van der, Freundlich, J., Combes, F., Tacconi, L., Genzel, R., Garcia-Burillo, S., Bolatto, A., Lilly, S., Salomé, P., Bicalho, I., Boissier, J., Boone, F., Bouché, N., Bournaud, F., Burkert, A., Carollo, M., Cooper, M., Feruglio, C., Förster Schreiber, N., Juneau, S., Lippa, M., Lutz, D., Naab, T., Renzini, A., Saintonge, A., Sternberg, A., Weiner, B., Weiß, A., Wuyts, S., Bouwens, Rychard, Brinchmann, Jarle, Maseda, Michael, Matthee, Jorryt, Schaye, Joop, Schouws, Sander, Pavesi, Riccardo, Le Fèvre, Olivier, Yang, C., Gavazzi, R., Beelen, A., Lehnert, M., Gao, Y., Barcos-Muñoz, L., Neri, R., Fu, H., González-Alfonso, E., Michałowski, M., Nightingale, J., Pérez-Fournon, I., Shao, Yali, Wang, Ran, Li, Jianan, Fan, Xiaohui, Jiang, Linhua, Strauss, Michael, Menten, Karl, Ma, Jingzhe, Cooray, Asantha, Nayyeri, Hooshang, Brown, Arianna, Ghotbi, Noah, Oteo, Ivan, Duivenvoorden, Steven, Greenslade, Joshua, Clements, David, Battisti, Andrew, Ashby, Matthew, Perez-Fournon, Ismael, Oliver, Seb, Eales, Stephen, Negrello, Mattia, Dye, Simon, Dunne, Loretta, Omont, Alain, Serjeant, Stephen, Maddox, Steve, Valiante, Elisabetta, Pillepich, Annalisa, Nelson, Dylan, Cunha, Elisabete da, Diemer, Benedikt, González-López, Jorge, Hernquist, Lars, Marinacci, Federico, Rix, Hans-Walter, Swinbank, Mark, Vogelsberger, Mark, Werf, Paul van der, Yung, L., Aravena, Manuel, Decarli, Roberto, Gónzalez-López, Jorge, Boogaard, Leindert, Carilli, Chris, Popping, Gergö, Assef, Roberto, Bacon, Roland, Bauer, Franz Erik, Bouwens, Richard, Contini, Thierry, Cortes, Paulo, Da Cunha, Elisabete, Daddi, Emanuele, Díaz-Santos, Tanio, Elbaz, David, Inami, Hanae, Fevre, Olivier Le, Magnelli, Benjamin, Oesch, Pascal, Riechers, Dominik, Somerville, Rachel, Uzgil, Bade, Wagg, Jeff, Wisotzki, Lutz, Gullberg, B., Swinbank, A. Mark, Smail, Ian, Biggs, A., Bertoldi, Frank, Breuck, C. De, Chapman, S., Chen, Chian-Chou, Cooke, E., Coppin, K., Cox, Pierre, Dannerbauer, H., Dunlop, J., Edge, A., Farrah, D., Geach, J., GREVE, T., Hodge, Jacqueline, Ibar, E., Ivison, Rob, Karim, A., Schinnerer, E., Scott, Douglas, Simpson, J., Stach, S., Thomson, A., Van Der Werf, Paul, Walter, Fabian, Wardlow, Julie, Weiss, Axel, 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), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Department of Physics, Durham University, Racah Institute of Physics, The Hebrew University of Jerusalem (HUJ), 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), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, AUTRES, 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-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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], Universitätssternwarte der Ludwig-Maximiliansuniversität, Ludwig-Maximiliansuniversität, Institute for Astronomy [Zürich], 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), Steward observatory, University of Arizona, Max-Planck-Institut für Extraterrestrische Physik (MPE), Institut of Physics - Riga, Latvian Academy of Sciences, Leiden Observatory [Leiden], Universiteit Leiden [Leiden], 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), Guangzhou Marine Geological Survey, Ministry of Land and Resources (MLR), Physics Department [Santa Barbara], University of California [Santa Barbara] (UCSB), University of California-University of California, 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), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL), Milieux aquatiques, écologie et pollutions (UR MALY), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Universidad de Alcalá - University of Alcalá (UAH), Instituto de Astrofisica de Canarias (IAC), Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Arizona State University [Tempe] (ASU), Max-Planck-Institut für Radioastronomie (MPIFR), California Institute of Technology (CALTECH), Astronomy Centre, University of Sussex, University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS), School of Physics and Astronomy [Cardiff], Cardiff University, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires de Marseille (ISM2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), School of Physics and Astronomy [Nottingham], University of Nottingham, UK (UON), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Max-Planck-Institut für Astronomie (MPIA), Institute for Computational Cosmology (ICC), National Radio Astronomy Observatory [Socorro] (NRAO), National Radio Astronomy Observatory (NRAO), 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), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS), 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, Yale Center for Astronomy and Astrophysics (YCAA), Yale University [New Haven], Cornell University, Rutgers University, Astrophysikalisches Institut Potsdam (AIP), Institute of Computational Cosmology, Argelander Institute for Astronomy (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Université de Lyon, SUPA, Institute for Astronomy, University of Edinburgh, University of Wales, Department of Physics [Blacksburg], Virginia Tech [Blacksburg], Space Plasma Group, Astronomy Unit [London] (AU), Queen Mary University of London (QMUL)-Queen Mary University of London (QMUL), Royal Observatory Edinburgh (ROE), Interactions et dynamique des environnements de surface (IDES), CLRC Daresbury, SFTC, Centre de Recherches sur la Cognition Animale (CRCA), Institut des sciences du cerveau de Toulouse. (ISCT), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Pacific Northwest National Laboratory (PNNL), Department of Astronomy, University of California [Irvine] (UCI), Centre de Biologie Intégrative (CBI), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut des sciences du cerveau de Toulouse. (ISCT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J)-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,FOS: Physical sciences ,galaxies [submillimeter] ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,0103 physical sciences ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,ComputingMilieux_MISCELLANEOUS ,evolution [galaxies] ,Physics ,[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,ISM [galaxies] ,010308 nuclear & particles physics ,Resolution (electron density) ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Redshift ,Galaxy ,Interstellar medium ,Space and Planetary Science ,[SDU]Sciences of the Universe [physics] ,Astrophysics of Galaxies (astro-ph.GA) ,Millimeter ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present deep high resolution (0.03", 200pc) ALMA Band 7 observations covering the dust continuum and [CII] $\lambda157.7\mu$m emission in four $z\sim4.4-4.8$ sub-millimeter galaxies (SMGs) selected from the ALESS and AS2UDS surveys. The data show that the rest-frame 160$\mu$m (observed 345 GHz) dust emission is consistent with smooth morphologies on kpc scales for three of the sources. One source, UDS47.0, displays apparent substructure but this is also consistent with a smooth morphology, as indicated by simulations showing that smooth exponential disks can appear clumpy when observed at high angular resolution (0.03") and depth of these observations ($\sigma_{345\text{GHz}} \sim27-47\mu$Jy beam$^{-1}$). The four SMGs are bright [CII] emitters, and we extract [CII] spectra from the high resolution data, and recover $\sim20-100$% of the [CII] flux and $\sim40-80$% of the dust continuum emission, compared to the previous lower resolution observations. When tapered to 0.2" resolution our maps recover $\sim80-100$% of the continuum emission, indicating that $\sim60$% of the emission is resolved out on $\sim200$pc scales. We find that the [CII] emission in high-redshift galaxies is more spatially extended than the rest-frame 160$\mu$m dust continuum by a factor of $1.6\pm0.4$. By considering the $L_{\text{[CII]}}$/$L_{\text{FIR}}$ ratio as a function of the star-formation rate surface density ($\Sigma_{\text{SFR}}$) we revisit the [CII] deficit, and suggest that the decline in the $L_{\text{[CII]}}$/$L_{\text{FIR}}$ ratio as a function of $\Sigma_{\text{SFR}}$ is consistent with local processes. We also explore the physical drivers that may be responsible for these trends and can give rise to the properties found in the densest regions of SMGs., Comment: 15 pages, 6 figures, 4 tables, accepted for publication in ApJ
- Published
- 2018
15. The unexpectedly large dust and gas content of quiescent galaxies at z \gt 1.4
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Gobat, R., Daddi, E., Magdis, G., Bournaud, F., Sargent, M., Martig, M., Jin, S., Finoguenov, A., Béthermin, M., Hwang, H.~S., Renzini, A., Wilson, G.~W., Aretxaga, I., Yun, M., Strazzullo, V., Valentino, F., 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), Liverpool John Moores University (LJMU), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Extraterrestrische Physik (MPE), Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE), University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS), Ludwig-Maximilians-Universität München (LMU), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Astrophysique Interprétation Modélisation (AIM (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), 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)
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[PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA] - Published
- 2018
16. Bulge formation through disc instability: I. Stellar discs.
- Author
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Devergne, T., Cattaneo, A., Bournaud, F., Koutsouridou, I., Winter, A., Dimauro, P., Mamon, G. A., Vacher, W., and Varin, M.
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GALACTIC evolution ,GALAXY formation ,STELLAR mass ,LUMINOSITY - Abstract
We use simulations to study the growth of a pseudobulge in an isolated thin exponential stellar disc embedded in a static spherical halo. We observe a transition from later to earlier morphological types and an increase in bar prominence for higher disc-to-halo mass ratios, for lower disc-to-halo size ratios, and for lower halo concentrations. We compute bulge-to-total stellar mass ratios B/T by fitting a two-component Sérsic-exponential surface-density distribution. The final B/T is strongly related to the disc's fractional contribution f
d to the total gravitational acceleration at the optical radius. The formula B/T = 0.5 fd 1.8 fits the simulations to an accuracy of 30%, is consistent with observational measurements of B/T and fd as a function of luminosity, and reproduces the observed relation between B/T and stellar mass when incorporated into the GALICS 2.0 semi-analytic model of galaxy formation. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
17. Formation of compact galaxies in the Extreme-Horizon simulation.
- Author
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Chabanier, S., Bournaud, F., Dubois, Y., Codis, S., Chapon, D., Elbaz, D., Pichon, C., Bressand, O., Devriendt, J., Gavazzi, R., Kraljic, K., Kimm, T., Laigle, C., Lekien, J.-B., Martin, G., Palanque-Delabrouille, N., Peirani, S., Piserchia, P.-F., Slyz, A., and Trebitsch, M.
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- *
INTERSTELLAR medium , *STELLAR mass , *ACTIVE galactic nuclei , *GALACTIC redshift , *GAS flow , *STAR formation , *GALAXY formation - Abstract
We present the Extreme-Horizon (EH) cosmological simulation, which models galaxy formation with stellar and active galactic nuclei (AGN) feedback and uses a very high resolution in the intergalactic and circumgalactic medium. Its high resolution in low-density regions results in smaller-size massive galaxies at a redshift of z = 2, which is in better agreement with observations compared to other simulations. We achieve this result thanks to the improved modeling of cold gas flows accreting onto galaxies. In addition, the EH simulation forms a population of particularly compact galaxies with stellar masses of 1010−11 M⊙ that are reminiscent of observed ultracompact galaxies at z ≃ 2. These objects form primarily through repeated major mergers of low-mass progenitors and independently of baryonic feedback mechanisms. This formation process can be missed in simulations with insufficient resolution in low-density intergalactic regions. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
18. GOODS-ALMA: The slow downfall of star formation in z = 2–3 massive galaxies.
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Franco, M., Elbaz, D., Zhou, L., Magnelli, B., Schreiber, C., Ciesla, L., Dickinson, M., Nagar, N., Magdis, G., Alexander, D. M., Béthermin, M., Demarco, R., Daddi, E., Wang, T., Mullaney, J., Sargent, M., Inami, H., Shu, X., Bournaud, F., and Chary, R.
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GALAXIES ,ELLIPTICAL galaxies ,SPECTRAL energy distribution ,STELLAR mass ,STARBURSTS ,STAR formation - Abstract
We investigate the properties of a sample of 35 galaxies, detected with the Atacama Large Millimeter/Submillimeter Array (ALMA) at 1.1 mm in the GOODS-ALMA field (area of 69 arcmin
2 , resolution = 0.60″, rms ≃ 0.18 mJy beam−1 ). Using the ultraviolet-to-radio deep multiwavelength coverage of the GOODS–South field, we fit the spectral energy distributions of these galaxies to derive their key physical properties. The galaxies detected by ALMA are among the most massive at z = 2−4 (M⋆, med = 8.5 × 1010 M⊙ ) and they are either starburst or located in the upper part of the galaxy star-forming main sequence. A significant portion of our galaxy population (∼40%), located at z ∼ 2.5 − 3, exhibits abnormally low gas fractions. The sizes of these galaxies, measured with ALMA, are compatible with the trend between the rest-frame 5000 Å size and stellar mass observed for z ∼ 2 elliptical galaxies, suggesting that they are building compact bulges. We show that there is a strong link between star formation surface density (at 1.1 mm) and gas depletion time: The more compact a galaxy's star-forming region is, the shorter its lifetime will be (without gas replenishment). The identified compact sources associated with relatively short depletion timescales (∼100 Myr) are the ideal candidates to be the progenitors of compact elliptical galaxies at z ∼ 2. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
19. GOODS-ALMA: Using IRAC and VLA to probe fainter millimeter galaxies.
- Author
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Franco, M., Elbaz, D., Zhou, L., Magnelli, B., Schreiber, C., Ciesla, L., Dickinson, M., Nagar, N., Magdis, G., Alexander, D. M., Béthermin, M., Demarco, R., Daddi, E., Wang, T., Mullaney, J., Inami, H., Shu, X., Bournaud, F., Chary, R., and Coogan, R. T.
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GALAXIES ,SPACE telescopes ,STELLAR mass ,DETECTION limit ,GALACTIC redshift ,STELLAR luminosity function ,SYNCOPE - Abstract
In this paper, we extend the source detection in the GOODS-ALMA field (69 arcmin
2 , 1σ ≃ 0.18 mJy beam−1 ) to deeper levels than presented in our previous work. Using positional information at 3.6 and 4.5 μm (from Spitzer-IRAC) as well as the Very Large Array (VLA) at 3 GHz, we explore the presence of galaxies detected at 1.1 mm with ALMA below our original blind detection limit of 4.8-σ, at which the number of spurious sources starts to dominate over that of real sources. In order to ensure the most reliable counterpart association possible, we have investigated the astrometry differences between different instruments in the GOODS–South field. In addition to a global offset between the Atacama Large Millimeter/submillimeter Array (ALMA) and the Hubble Space Telescope (HST) already discussed in previous studies, we have highlighted a local offset between ALMA and the HST that was artificially introduced in the process of building the mosaic of the GOODS–South image. We created a distortion map that can be used to correct for these astrometric issues. In this Supplementary Catalog, we find a total of 16 galaxies, including two galaxies with no counterpart in HST images (also known as optically dark galaxies), down to a 5σ limiting depth of H = 28.2 AB (HST/WFC3 F160W). This brings the total sample of GOODS-ALMA 1.1 mm sources to 35 galaxies. Galaxies in the new sample cover a wider dynamic range in redshift (z = 0.65−4.73), are on average twice as large (1.3 vs 0.65 kpc), and have lower stellar masses (M⋆ SC M ⋆ SC $ M_{\star}^{\mathrm{SC}} $ = 7.6 × 1010 M⊙ vs M⋆ MC M ⋆ MC $ M_{\star}^{\mathrm{MC}} $ = 1.2 × 1011 M⊙ ). Although exhibiting larger physical sizes, these galaxies still have far-infrared sizes that are significantly more compact than inferred from their optical emission. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
20. GOODS-ALMA: Optically dark ALMA galaxies shed light on a cluster in formation at z = 3.5.
- Author
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Zhou, L., Elbaz, D., Franco, M., Magnelli, B., Schreiber, C., Wang, T., Ciesla, L., Daddi, E., Dickinson, M., Nagar, N., Magdis, G., Alexander, D. M., Béthermin, M., Demarco, R., Mullaney, J., Bournaud, F., Ferguson, H., Finkelstein, S. L., Giavalisco, M., and Inami, H.
- Subjects
GALAXIES ,SPECTRAL energy distribution ,SUBMILLIMETER astronomy ,ACTIVE galactic nuclei ,GALAXY formation ,ACTIVE galaxies ,STAR formation - Abstract
Thanks to its outstanding angular resolution, the Atacama Large Millimeter/submillimeter Array (ALMA) has recently unambiguously identified a population of optically dark galaxies with redshifts greater than z = 3, which play an important role in the cosmic star formation in massive galaxies. In this paper we study the properties of the six optically dark galaxies detected in the 69 arcmin
2 GOODS-ALMA 1.1 mm continuum survey. While none of them are listed in the deepest H-band based CANDELS catalog in the GOODS-South field down to H = 28.16 AB, we were able to de-blend two of them from their bright neighbor and measure an H-band flux for them. We present the spectroscopic scan follow-up of five of the six sources with ALMA band 4. All are detected in the 2 mm continuum with signal-to-noise ratios higher than eight. One emission line is detected in AGS4 (νobs = 151.44 GHz with an S/N = 8.58) and AGS17 (νobs = 154.78 GHz with an S/N = 10.23), which we interpret in both cases as being due to the CO(6–5) line at zspec AGS4 z spec AGS 4 $ z^{\mathrm{AGS4}}_{\mathrm{spec}} $ = 3.556 and zspec AGS17 z spec AGS 17 $ z^{\mathrm{AGS17}}_{\mathrm{spec}} $ = 3.467, respectively. These redshifts match both the probability distribution of the photometric redshifts derived from the UV to near-infrared spectral energy distributions (SEDs) and the far-infrared SEDs for typical dust temperatures of galaxies at these redshifts. We present evidence that nearly 70% (4/6 of galaxies) of the optically dark galaxies belong to the same overdensity of galaxies at z ∼ 3.5. overdensity The most massive one, AGS24 (M⋆ = 1011.32 M−0.19 +0.02 ⊙ 11. 32 − 0.19 + 0.02 M ⊙ $ ^{11.32^{+0.02}_{-0.19}}\,M_{\odot} $), is the most massive galaxy without an active galactic nucleus at z > 3 in the GOODS-ALMA field. It falls in the very center of the peak of the galaxy surface density, which suggests that the surrounding overdensity is a proto-cluster in the process of virialization and that AGS24 is the candidate progenitor of the future brightest cluster galaxy. [ABSTRACT FROM AUTHOR]- Published
- 2020
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21. Local Starburst Conditions and Formation of GRB 980425/SN 1998bw within a Collisional Ring.
- Author
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Arabsalmani, M., Renaud, F., Roychowdhury, S., Arumugam, V., Floc'h, E. Le, Bournaud, F., Cormier, D., Zwaan, M. A., Christensen, L., Pian, E., Madden, S., and Levan, A.
- Subjects
STARBURSTS ,GAMMA ray bursts ,STAR clusters ,SUPERGIANT stars ,STAR formation ,MOLECULAR weights - Abstract
We present the first spatially resolved study of molecular gas in the vicinity of a gamma-ray burst (GRB), using CO(2−1) emission-line observations with the Atacama Large Millimetre Array at ∼50 pc scales. The host galaxy of GRB 980425 contains a ring of high column density H i gas, which is likely to have formed due to a collision between the GRB host and its companion galaxy, within which the GRB is located. We detect 11 molecular gas clumps in the galaxy, 7 of which are within the gas ring. The clump closest to the GRB position is at a projected separation of ∼280 pc. Although it is plausible that the GRB progenitor was ejected from clusters formed in this clump, we argue that the in situ formation of the GRB progenitor is the most likely scenario. We measure the molecular gas masses of the clumps and find them to be sufficient for forming massive star clusters. The molecular gas depletion times of the clumps show a variation of ∼2 dex, comparable with the large variation in depletion times found in starburst galaxies in the nearby universe. This demonstrates the presence of starburst modes of star formation on local scales in the galaxy, even while the galaxy as a whole cannot be categorized as a starburst based on its global properties. Our findings suggest that the progenitor of GRB 9802425 was originated in a young massive star cluster formed in the starburst mode of star formation. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
22. A contribution of star-forming clumps and accreting satellites to the mass assembly of z ∼ 2 galaxies.
- Author
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Zanella, A, Le Floc'h, E, Harrison, C M, Daddi, E, Bernhard, E, Gobat, R, Strazzullo, V, Valentino, F, Cibinel, A, Sánchez Almeida, J, Kohandel, M, Fensch, J, Behrendt, M, Burkert, A, Onodera, M, Bournaud, F, and Scholtz, J
- Subjects
GALAXIES ,DISK galaxies ,SPECTRAL imaging ,STELLAR mass ,STAR formation ,AGE of stars ,RED giants - Abstract
We investigate the contribution of clumps and satellites to the galaxy mass assembly. We analysed spatially resolved HubbleSpace Telescope observations (imaging and slitless spectroscopy) of 53 star-forming galaxies at z ∼ 1–3. We created continuum and emission line maps and pinpointed residual 'blobs' detected after subtracting the galaxy disc. Those were separated into compact (unresolved) and extended (resolved) components. Extended components have sizes ∼2 kpc and comparable stellar mass and age as the galaxy discs, whereas the compact components are 1.5 dex less massive and 0.4 dex younger than the discs. Furthermore, the extended blobs are typically found at larger distances from the galaxy barycentre than the compact ones. Prompted by these observations and by the comparison with simulations, we suggest that compact blobs are in situ formed clumps, whereas the extended ones are accreting satellites. Clumps and satellites enclose, respectively, ∼20 per cent and ≲80 per cent of the galaxy stellar mass, ∼30 per cent and ∼20 per cent of its star formation rate. Considering the compact blobs, we statistically estimated that massive clumps (M
⋆ ≳ 109 M⊙ ) have lifetimes of ∼650 Myr, and the less massive ones (108 < M⋆ < 109 M⊙ ) of ∼145 Myr. This supports simulations predicting long-lived clumps (lifetime ≳ 100 Myr). Finally, ≲30 per cent (13 per cent) of our sample galaxies are undergoing single (multiple) merger(s), they have a projected separation ≲10 kpc, and the typical mass ratio of our satellites is 1:5 (but ranges between 1:10 and 1:1), in agreement with literature results for close pair galaxies. [ABSTRACT FROM AUTHOR]- Published
- 2019
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23. Gemini GMOS and WHT SAURON integral-field spectrograph observations of the AGN-driven outflow in NGC 1266
- Author
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Davis, T, Krajnovic, D, McDermid, R, Bureau, M, Sarzi, M, Nyland, K, Alatalo, K, Bayet, E, Blitz, L, Bois, M, Bournaud, F, Cappellari, M, Crocker, A, Davies, R, de Zeeuw, P, Duc, P, Emsellem, E, Khochfar, S, Kuntschner, H, Lablanche, P, Morganti, R, Naab, T, Oosterloo, T, Scott, N, and Serra, P
- Abstract
We use the Spectrographic Areal Unit for Research on Optical Nebulae and Gemini Multi-Object Spectrograph integral-field spectrographs to observe the active galactic nucleus (AGN) powered outflow in NGC1266. This unusual galaxy is relatively nearby (D = 30Mpc), allowing us to investigate the process of AGN feedback in action. We present maps of the kinematics and line strengths of the ionized gas emission lines Hα, Hβ, [Oiii], [Oi], [Nii] and [Sii], and report on the detection of sodium D absorption. We use these tracers to explore the structure of the source, derive the ionized and atomic gas kinematics, and investigate the gas excitation and physical conditions. NGC1266 contains two ionized gas components along most lines of sight, tracing the ongoing outflow and a component closer to the galaxy systemic, the origin of which is unclear. This gas appears to be disturbed by a nascent AGN jet. We confirm that the outflow in NGC1266 is truly multiphase, containing radio plasma, atomic, molecular and ionized gas and X-ray emitting plasma. The outflow has velocities of up to ±900 km s -1 away from the systemic velocity and is very likely to remove significant amount of cold gas from the galaxy. The low-ionization nuclear emission region-like line emission in NGC1266 is extended, and it likely arises from fast shocks caused by the interaction of the radio jet with the interstellar medium. These shocks have velocities of up to 800 km s -1, which match well with the observed velocity of the outflow. Sodium D equivalent width profiles are used to set constraints on the size and orientation of the outflow. The ionized gas morphology correlates with the nascent radio jets observed in 1.4 and 5 GHz continuum emission, supporting the suggestion that an AGN jet is providing the energy required to drive the outflow. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.
- Published
- 2016
24. The ATLAS(3D) project - I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria
- Author
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Cappellari, M, Emsellem, E, Krajnovic, D, McDermid, R, Scott, N, Kleijn, G, Young, L, Alatalo, K, Bacon, R, Blitz, L, Bois, M, Bournaud, F, Bureau, M, Davies, R, Davis, T, de Zeeuw, P, Duc, P, Khochfar, S, Kuntschner, H, Lablanche, P, Morganti, R, Naab, T, Oosterloo, T, Sarzi, M, and Serra, P
- Abstract
The ATLAS3D project is a multiwavelength survey combined with a theoretical modelling effort. The observations span from the radio to the millimetre and optical, and provide multicolour imaging, two-dimensional kinematics of the atomic (Hi), molecular (CO) and ionized gas (Hβ, [Oiii] and [Ni]), together with the kinematics and population of the stars (Hβ, Fe5015 and Mg b), for a carefully selected, volume-limited (1.16 × 105Mpc3) sample of 260 early-type (elliptical E and lenticular S0) galaxies (ETGs). The models include semi-analytic, N-body binary mergers and cosmological simulations of galaxy formation. Here we present the science goals for the project and introduce the galaxy sample and the selection criteria. The sample consists of nearby (D < 42Mpc, |δ- 29°| < 35°, |b| > 15°) morphologically selected ETGs extracted from a parent sample of 871 galaxies (8 per cent E, 22 per cent S0 and 70 per cent spirals) brighter than MK < -21.5mag (stellar mass M{black star}≳ 6 ×109M⊙). We analyse possible selection biases and we conclude that the parent sample is essentially complete and statistically representative of the nearby galaxy population. We present the size-luminosity relation for the spirals and ETGs and show that the ETGs in the ATLAS3D sample define a tight red sequence in a colour-magnitude diagram, with few objects in the transition from the blue cloud. We describe the strategy of the SAURON integral field observations and the extraction of the stellar kinematics with the ppxf method. We find typical 1σ errors of ΔV≈ 6kms-1, Δσ≈ 7kms-1, Δh3≈Δh4≈ 0.03 in the mean velocity, the velocity dispersion and Gauss-Hermite (GH) moments for galaxies with effective dispersion σe≳ 120kms-1. For galaxies with lower σe (≈40 per cent of the sample) the GH moments are gradually penalized by ppxf towards zero to suppress the noise produced by the spectral undersampling and only V and σ can be measured. We give an overview of the characteristics of the other main data sets already available for our sample and of the ongoing modelling projects. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.
- Published
- 2016
25. The ATLAS3D project - IX. The merger origin of a fast- and a slow-rotating early-type galaxy revealed with deep optical imaging: first results
- Author
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Duc, P, Cuillandre, J, Serra, P, Michel-Dansac, L, Ferriere, E, Alatalo, K, Blitz, L, Bois, M, Bournaud, F, Bureau, M, Cappellari, M, Davies, R, Davis, T, de Zeeuw, P, Emsellem, E, Khochfar, S, Krajnovic, D, Kuntschner, H, Lablanche, P, McDermid, R, Morganti, R, Naab, T, Oosterloo, T, Sarzi, M, and Scott, N
- Abstract
The mass assembly of galaxies leaves imprints in their outskirts, such as shells and tidal tails. The frequency and properties of such fine structures depend on the main acting mechanisms - secular evolution, minor or major mergers - and on the age of the last substantial accretion event. We use this to constrain the mass assembly history of two apparently relaxed nearby early-type galaxies (ETGs) selected from the ATLAS3D sample, NGC 680 and 5557. Our ultra-deep optical images obtained with MegaCam on the Canada-France-Hawaii Telescope reach 29 magarcsec-2 in thegband. They reveal very low surface brightness (LSB) filamentary structures around these ellipticals. Among them, a gigantic 160kpc long, narrow, tail east of NGC 5557 hosts three gas-rich star-forming objects, previously detected in Hi with the Westerbork Synthesis Radio Telescope and in UV withGALEX. NGC 680 exhibits two major diffuse plumes apparently connected to extended Hi tails, as well as a series of arcs and shells. Comparing the outer stellar and gaseous morphology of the two ellipticals with that predicted from models of colliding galaxies, we argue that the LSB features are tidal debris and that each of these two ETGs was assembled during a relatively recent, major wet merger, which most likely occurred after the redshiftz≃ 0.5 epoch. Had these mergers been older, the tidal features should have already fallen back or be destroyed by more recent accretion events. However, the absence of molecular gas and of a prominent young stellar population in the core region of the galaxies indicates that the merger is at least 1-2 Gyr old: the memory of any merger-triggered nuclear starburst has indeed been lost. The star-forming objects found towards the collisional debris of NGC 5557 are then likely tidal dwarf galaxies. Such recycled galaxies here appear to be long-lived and continue to form stars while any star formation activity has stopped in their parent galaxy. The inner kinematics of NGC 680 is typical for fast rotators which make the bulk of nearby ETGs in the ATLAS3D sample. On the other hand, NGC 5557 belongs to the poorly populated class of massive, round, slow rotators that are predicted by semi-analytic models and cosmological simulations to be the end-product of a complex mass accretion history, involving ancient major mergers and more recent minor mergers. Our observations suggest that under specific circumstances a single binary merger may dominate the formation history of such objects and thus that at least some massive ETGs may form at relatively low redshift. Whether the two galaxies studied here are representative of their own sub-class of ETGs is still an open question that will be addressed by an on-going deep optical survey of ATLAS3D galaxies. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.
- Published
- 2016
26. The ATLAS(3D) project-XIII. Mass and morphology of HI in early-type galaxies as a function of environment
- Author
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Serra, P, Oosterloo, T, Morganti, R, Alatalo, K, Blitz, L, Bois, M, Bournaud, F, Bureau, M, Cappellari, M, Crocker, A, Davies, R, Davis, T, de Zeeuw, P, Duc, P, Emsellem, E, Khochfar, S, Krajnovic, D, Kuntschner, H, Lablanche, P, McDermid, R, Naab, T, Sarzi, M, Scott, N, Trager, S, and Weijmans, A
- Abstract
We present the ATLAS 3D Hi survey of a volume-limited, complete sample of 166 nearby early-type galaxies (ETGs) brighter than M K=-21.5. The survey is mostly based on data taken with the Westerbork Synthesis Radio Telescope, which enables us to detect Hi down to 5 × 10 6-5 × 10 7M ⊙ within the survey volume. We detect ~40per cent of all ETGs outside the Virgo galaxy cluster and ~10per cent of all ETGs inside it. This demonstrates that it is common for non-cluster ETGs to host Hi. The morphology of the detected gas varies in a continuous way from regular, settled Hi discs and rings to unsettled gas distributions (including tidal or accretion tails) and systems of clouds scattered around the galaxy. The majority of the detections consist of Hi discs or rings (1/4 of all ETGs outside Virgo) so that if Hi is detected in an ETG it is most likely distributed on a settled configuration. These systems come in two main types: small discs [M ⊙], which are confined within the stellar body and share the same kinematics of the stars; and large discs/rings [M(Hi) up to 5 × 10 9M ⊙], which extend to tens of kpc from the host galaxy and are in half of the cases kinematically decoupled from the stars. Neutral hydrogen seems to provide material for star formation in ETGs. Galaxies containing Hi within ~1R e exhibit signatures of on-going star formation in ~70per cent of the cases, approximately five times more frequently than galaxies without central Hi. The interstellar medium (ISM) in the centre of these galaxies is dominated by molecular gas, and in ETGs with a small gas disc the conversion of Hi into H 2 is as efficient as in spirals. The ETG Hi mass function is characterized by M*~ 2 × 10 9M ⊙ and by a slope α~-0.7. Compared to spirals, ETGs host much less Hi as a family. However, a significant fraction of all ETGs are as Hi-rich as spiral galaxies. The main difference between ETGs and spirals is that the former lack the high-column-density Hi typical of the bright stellar disc of the latter. The ETG Hi properties vary with environment density in a more continuous way than suggested by the known Virgo versus non-Virgo dichotomy. We find an envelope of decreasing M(Hi) and M(Hi)/L K with increasing environment density. The gas-richest galaxies live in the poorest environments (as found also with CO observations), where the detection rate of star formation signatures is higher. Galaxies in the centre of Virgo have the lowest Hi content, while galaxies at the outskirts of Virgo represent a transition region and can contain significant amounts of Hi, indicating that at least a fraction of them has joined the cluster only recently after pre-processing in groups. Finally, we find an Hi morphology-density relation such that at low environment density (measured on a local scale) the detected Hi is mostly distributed on large, regular discs and rings, while more disturbed Hi morphologies dominate environment densities typical of rich groups. This confirms the importance of processes occurring on a galaxy-group scale for the evolution of ETGs. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.
- Published
- 2016
27. GOODS-Herschel: the far-infrared view of star formation in active galactic nucleus host galaxies since z similar to 3
- Author
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Mullaney, JR, Pannella, M, Daddi, E, Alexander, D, Elbaz, D, Hickox, R, Bournaud, F, Altieri, B, Aussel, H, Coia, D, Dannerbauer, H, Dasyra, K, Dickinson, M, Hwang, H, Kartaltepe, J, Leiton, R, Magdis, G, Magnelli, B, Popesso, P, Valtchanov, I, Bauer, F, Brandt, W, Del Moro, A, Hanish, D, and Ivison, R
- Abstract
We present a study of the infrared properties of X-ray selected, moderate-luminosity (i.e.LX= 1042-1044ergs-1) active galactic nuclei (AGNs) up toz≈ 3, in order to explore the links between star formation in galaxies and accretion on to their central black holes. We use 100 and 160μ mfluxes from GOODS-Herschel- the deepest survey yet undertaken by theHerscheltelescope - and show that in the vast majority of cases (i.e. >94percent) these fluxes are dominated by emission from the host galaxy. As such, these far-infrared bands provide an uncontaminated view of star formation in the AGN host galaxies. We find no evidence of any correlation between the X-ray and infrared luminosities of moderate AGNs at any redshift, suggesting that global star formation is decoupled from nuclear (i.e. AGN) activity in these galaxies. On the other hand, we confirm that the star formation rates of AGN hosts increase strongly with redshift, by a factor of 43+27- 18 fromz< 0.1 toz= 2-3 for AGNswith the same range of X-ray luminosities. This increase is entirely consistent with the factor of 25-50 increase in the specific star formation rates (SSFRs) of normal, star-forming (i.e. main-sequence) galaxies over the same redshift range. Indeed, the average SSFRs of AGN hosts are only marginally (i.e. ≈20percent) lower than those of main-sequence galaxies at all surveyed redshifts, with this small deficit being due to a fraction of AGNs residing in quiescent (i.e. low SSFR) galaxies. We estimate that 79 ± 10percent of moderate-luminosity AGNs are hosted in main-sequence galaxies, 15 ± 7percent in quiescent galaxies and
- Published
- 2016
28. High-resolution Imaging of PHIBSS z sim 2 Main-sequence Galaxies in CO J = 1 rarr 0
- Author
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Bolatto, A. D., Warren, S. R., Leroy, A. K., Tacconi, L. J., Bouché, N., Förster Schreiber, N. M., Genzel, R., Cooper, M. C., Fisher, D. B., Combes, F., García-Burillo, S., Burkert, A., Bournaud, F., Weiss, A., Saintonge, A., Wuyts, S., and Sternberg, A.
- Subjects
Astrophysics::Cosmology and Extragalactic Astrophysics ,evolution, galaxies: high-redshift, galaxies: ISM, ISM: molecules [galaxies] ,Astrophysics::Galaxy Astrophysics - Abstract
We present Karl Jansky Very Large Array observations of the CO $J=1-0$ transition in a sample of four $z\sim 2$ main-sequence galaxies. These galaxies are in the blue sequence of star-forming galaxies at their redshift, and are part of the IRAM Plateau de Bure HIgh-z Blue Sequence Survey which imaged them in CO $J=3-2$. Two galaxies are imaged here at high signal-to-noise, allowing determinations of their disk sizes, line profiles, molecular surface densities, and excitation. Using these and published measurements, we show that the CO and optical disks have similar sizes in main-sequence galaxies, and in the galaxy where we can compare CO $J=1-0$ and $J=3-2$ sizes we find these are also very similar. Assuming a Galactic CO-to-H2 conversion, we measure surface densities of ${{\rm{\Sigma }}}_{\mathrm{mol}}\sim 1200$ ${M}_{\odot }$ pc−2 in projection and estimate ${{\rm{\Sigma }}}_{\mathrm{mol}}$~ 500–900 ${M}_{\odot }$ pc−2 deprojected. Finally, our data yields velocity-integrated Rayleigh–Jeans brightness temperature line ratios r31 that are approximately at unity. In addition to the similar disk sizes, the very similar line profiles in $J=1-0$ and $J=3-2$ indicate that both transitions sample the same kinematics, implying that their emission is coextensive. We conclude that in these two main-sequence galaxies there is no evidence for significant excitation gradients or a large molecular reservoir that is diffuse or cold and not involved in active star formation. We suggest that r31 in very actively star-forming galaxies is likely an indicator of how well-mixed the star formation activity and the molecular reservoir are.
- Published
- 2015
29. Sunyaev-Zel'dovich detection of the galaxy cluster Cl J1449+0856 at z = 1.99: The pressure profile in uv space.
- Author
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Gobat, R., Daddi, E., Coogan, R. T., Le Brun, A. M. C., Bournaud, F., Melin, J.-B., Riechers, D. A., Sargent, M., Valentino, F., Hwang, H. S., Finoguenov, A., and Strazzullo, V.
- Subjects
GALAXY clusters ,SUNYAEV-Zel'dovich effect ,PRESSURE - Abstract
We present Atacama Large Millimetre Array and Atacama Compact Array observations of the Sunyaev-Zel'dovich effect in the z = 2 galaxy cluster Cl J1449+0856, an X-ray-detected progenitor of typical massive clusters in the present day Universe. While in a cleaned but otherwise untouched 92 GHz map of this cluster little to no negative signal is visible, careful subtraction of known sub-millimetre emitters in the uv plane reveals a decrement at 5σ significance. The total signal is −190 ± 36 μJy, with a peak offset by 5″–9″ (∼50 kpc) from both the X-ray centroid and the still-forming brightest cluster galaxy. A comparison of the recovered uv-amplitude profile of the decrement with different pressure models allows us to derive total mass constraints consistent with the ∼6 × 10
13 M⊙ estimated from X-ray data. Moreover, we find no strong evidence for a deviation of the pressure profile with respect to local galaxy clusters, although a slight tension at small-to-intermediate spatial scales suggests a flattened central profile, opposite to that seen in a cool core and possibly an AGN-related effect. This analysis of the lowest mass single SZ detection so far illustrates the importance of interferometers when observing the SZ effect in high-redshift clusters, the cores of which cannot be considered quiescent, such that careful subtraction of galaxy emission is necessary. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
30. The host galaxy of GRB 980425/SN1998bw: a collisional ring galaxy.
- Author
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Arabsalmani, M, Roychowdhury, S, Starkenburg, T K, Christensen, L, Le Floc'h, E, Kanekar, N, Bournaud, F, Zwaan, M A, Fynbo, J P U, Møller, P, and Pian, E
- Subjects
GAMMA ray bursts ,GALAXIES ,STELLAR mass ,STAR formation ,VERY large telescopes ,RADIO telescopes - Abstract
We report Giant Metrewave Radio Telescope (GMRT), Very Large Telescope (VLT), and Spitzer Space Telescope observations of ESO 184−G82, the host galaxy of GRB 980425/SN 1998bw, that yield evidence of a companion dwarf galaxy at a projected distance of 13 kpc. The companion, hereafter GALJ193510-524947, is a gas-rich, star-forming galaxy with a star formation rate of |$\rm 0.004\, M_{\odot }\, yr^{-1}$|, a gas mass of |$10^{7.1\pm 0.1} \, \mathrm{M}_{\odot}$|, and a stellar mass of |$10^{7.0\pm 0.3} \, \mathrm{M}_{\odot}$|. The interaction between ESO 184−G82 and GALJ193510-524947 is evident from the extended gaseous structure between the two galaxies in the GMRT H i 21 cm map. We find a ring of high column density H i gas, passing through the actively star-forming regions of ESO 184−G82 and the GRB location. This ring lends support to the picture in which ESO 184−G82 is interacting with GALJ193510-524947. The massive stars in GALJ193510-524947 have similar ages to those in star-forming regions in ESO 184−G82, also suggesting that the interaction may have triggered star formation in both galaxies. The gas and star formation properties of ESO 184−G82 favour a head-on collision with GALJ193510-524947 rather than a classical tidal interaction. We perform state-of-the-art simulations of dwarf–dwarf mergers and confirm that the observed properties of ESO 184−G82 can be reproduced by collision with a small companion galaxy. This is a very clear case of interaction in a gamma-ray burst host galaxy and of interaction-driven star formation giving rise to a gamma-ray burst in a dense environment. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
31. Early- and late-stage mergers among main sequence and starburst galaxies at 0.2 ≤ z ≤ 2.
- Author
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Cibinel, A, Daddi, E, Sargent, M T, Le Floc'h, E, Liu, D, Bournaud, F, Oesch, P A, Amram, P, Calabrò, A, Duc, P-A, Pannella, M, Puglisi, A, Perret, V, Elbaz, D, and Kokorev, V
- Subjects
STAR formation ,STELLAR mass ,STARBURSTS ,DIFFERENTIAL evolution ,GALAXIES ,GALACTIC evolution - Abstract
We investigate the fraction of close pairs and morphologically identified mergers on and above the star-forming main sequence (MS) at 0.2 ≤ z ≤2.0. The novelty of our work lies in the use of a non-parametric morphological classification performed on resolved stellar mass maps, reducing the contamination by non-interacting, high-redshift clumpy galaxies. We find that the merger fraction rapidly rises to ≥70 per cent above the MS, implying that – already at z ≳ 1 – starburst (SB) events (Δ
MS ≥ 0.6) are almost always associated with a major merger (1:1 to 1:6 mass ratio). The majority of interacting galaxies in the SB region are morphologically disturbed, late-stage mergers. Pair fractions show little dependence on MS offset and pairs are more prevalent than late-stage mergers only in the lower half of the MS. In our sample, major mergers on the MS occur with a roughly equal frequency of ∼5–10 per cent at all masses ≳ 1010 M⊙ . The MS major merger fraction roughly doubles between z = 0.2 and 2, with morphological mergers driving the overall increase at z ≳ 1. The differential redshift evolution of interacting pairs and morphologically classified mergers on the MS can be reconciled by evolving observability time-scales for both pairs and morphological disturbances. The observed variation of the late-stage merger fraction with ΔMS follows the perturbative 2-Star Formation Mode model, where any MS galaxy can experience a continuum of different star formation rate enhancements. This points to an SB–merger connection not only for extreme events, but also more moderate bursts which merely scatter galaxies upward within the MS, rather than fully elevating them above it. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
32. Evolution of the mass, size, and star formation rate in high redshift merging galaxies
- Author
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Perret, V., Renaud, F., Epinat, B., Amram, P., Bournaud, F., Contini, T., Teyssier, R., Lambert, J.-C., 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), 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, Institut de recherche en astrophysique et planétologie (IRAP), 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), Institute for Theoretical Physics, Universität Zürich [Zürich] = University of Zurich (UZH), University of Zurich, Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université 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), and 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)
- Subjects
530 Physics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,methods: numerical ,1912 Space and Planetary Science ,galaxies: high-redshift ,10231 Institute for Computational Science ,galaxies: star formation ,galaxies: interactions ,3103 Astronomy and Astrophysics ,Astrophysics::Solar and Stellar Astrophysics ,galaxies: formation ,Astrophysics::Earth and Planetary Astrophysics ,galaxies: evolution ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Astrophysics::Galaxy Astrophysics - Abstract
International audience; Context. In Λ-CDM models, galaxies are thought to grow both through continuous cold gas accretion coming from the cosmic web and episodic merger events. The relative importance of these different mechanisms at different cosmic epochs is nevertheless not yet understood well.Aims. We aim to address questions related to galaxy mass assembly through major and minor wet merging processes in the redshift range 1
- Published
- 2014
33. High resolution spectroscopy of Red Giant Branch stars and the chemical evolution of the Fornax dwarf spheroidal galaxy
- Author
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Lemasle, B., de Boer, T. J. L., Hill, V., Tolstoy, E., Irwin, M. J., Jablonka, P., Venn, K., Battaglia, G., Starkenburg, E., Shetrone, M., Letarte, B., Francois, P., Helmi, A., Primas, F., Kaufer, A., Szeifert, T., Ballet, J., Martins, F., Bournaud, F., Monier, R., Reylé, C., Low Energy Astrophysics (API, FNWI), and Astronomy
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galaxies: individual: Fornax dwarf spheroidal ,stars: abundances ,galaxies: evolution - Abstract
From VLT-FLAMES high-resolution spectra, we determine the abundances of several α, iron-peak and neutron-capture elements in 47 Red Giant Branch stars in the Fornax dwarf spheroidal galaxy. We confirm that SNe Ia started to contribute to the chemical enrichment of Fornax at [Fe/H] between --2.0 and --1.8 dex. Combining these abundances with accurate age estimates, we date the onset of SNe Ia to ≈ 12--10 Gyrs ago. Our results are compatible with an initial mass function that lacks the most massive stars and with a star formation going on throughout the whole history of Fornax.
- Published
- 2014
34. Simulations of Binary Galaxy Mergers and the Link with Fast Rotators, Slow Rotators, and Kinematically Distinct Cores
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Bois, M., Emsellem, E., Bournaud, F., Alatalo, K., Blitz, L., Bureau, M., Cappellari, M., Davies, R. L., Davis, T. A., de Zeeuw, P. T., Duc, P. -A, Khochfar, S., Krajnović, D, Thomas, D., Kuntschner, H., Lablanche, P. -Y, McDermid, R. M., Morganti, R., Naab, T., Oosterloo, T., Sarzi, M., Scott, N., Serra, P., Weijmans, A. -M, Young, L. M., Sun, W. -H, Xu, C. K., Scoville, N. Z., Sanders, D. B., and Astronomy
- Subjects
Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
We study the formation of early-type galaxies (ETGs) through mergers with a sample of 70 high-resolution numerical simulations of binary mergers of disc galaxies. These simulations encompass various mass ratios, initial conditions and orbital parameters. We find that binary mergers of disc galaxies with mass ratios of 3:1 and 6:1 are nearly always classified as Fast Rotators according to the ATLAS3D criterion: they preserve the structure of the input fast rotating spiral progenitors. Major disc mergers (mass ratios of 2:1 and 1:1) lead to both Fast and Slow Rotators. Most of the Slow Rotators hold a stellar Kinematically Distinct Core (KDC) in their 1-3 central kilo-parsec: these KDCs are built from the stellar components of the progenitors. The mass ratio of the progenitors is a fundamental parameter for the formation of Slow Rotators in binary mergers, but it also requires a retrograde spin for the progenitor galaxies with respect to the orbital angular momentum. The importance of the initial spin of the progenitors is also investigated in the library of galaxy mergers of the GalMer project.
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- 2013
35. A sub-parsec resolution simulation of the Milky Way: Global structure of the ISM and properties of molecular clouds
- Author
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Renaud, F., Bournaud, F., Emsellem, E., Elmegreen, B., Teyssier, R., Alves, J., Chapon, D., Combes, F., Dekel, A., Gabor, J., Hennebelle, P., and Kraljic, K.
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Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present a self-consistent hydrodynamical simulation of a Milky Way-like galaxy, at the resolution of 0.05 pc. The model includes star formation and a new implementation of stellar feedback through photo-ionization, radiative pressure and supernovae. The simulation resolves the structure of the interstellar medium at subparsec resolution for a few cloud lifetimes, and at 0.05 pc for about a cloud crossing time. Turbulence cascade and gravitation from the kpc scales are de facto included in smaller structures like molecular clouds. We show that the formation of a bar influences the dynamics of the central ~100 pc by creating resonances. At larger radii, the spiral arms host the formation of regularly spaced clouds: beads on a string and spurs. These instabilities pump turbulent energy into the gas, generally in the supersonic regime. Because of asymmetric drift, the supernovae explode outside of their gaseous nursery, which diminishes the effect of feedback on the structure of clouds. The evolution of clouds is thus mostly due to fragmentation and gas consumption, regulated mainly by supersonic turbulence. The transition from turbulence supported to self-gravitating gas is detected in the gas density probability distribution function at ~2000 cm^-3. The power spectrum density suggests that gravitation governs the hierarchical organisation of structures from the galactic scale down to a few parsecs., MNRAS accepted
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- 2013
36. Quenching of Star Formation in Molecular Outflow Host NGC 1266
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Alatalo, K., Nyland, K. E., Graves, G., Deustua, S., Young, L. M., Davis, T. A., Crocker, A. F., Bureau, M., Bayet, E., Blitz, L., Bois, M., Bournaud, F., Cappellari, M., Davies, R. L., de Zeeuw, P. T., Emsellem, E., Khochfar, S., Krajnovic, D., Kuntschner, H., McDermid, R. M., Morganti, R., Naab, T., Oosterloo, T., Sarzi, M., Scott, N., Serra, P., Weijmans, A., Wong, Tony, Ott, Jürgen, and Astronomy
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Physics ,Quenching ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Stellar population ,Star formation ,galaxies: active ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Galaxy ,Stars ,Space and Planetary Science ,galaxies: individual (NGC 1266) ,Outflow ,galaxies: evolution ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We detail the rich molecular story of NGC 1266, its serendipitous discovery within the ATLAS3D survey (Cappellari et al. 2011) and how it plays host to an AGN-driven molecular outflow, potentially quenching all of its star formation (SF) within the next 100 Myr. While major mergers appear to play a role in instigating outflows in other systems, deep imaging of NGC 1266 as well as stellar kinematic observations from SAURON, have failed to provide evidence that NGC 1266 has recently been involved in a major interaction. The molecular gas and the instantaneous SF tracers indicate that the current sites of star formation are located in a hypercompact disk within 200 pc of the nucleus (Fig. 1; SF rate ~ 2 Msuns/yr). On the other hand, tracers of recent star formation, such as the H{\beta} absorption map from SAURON and stellar population analysis show that the young stars are distributed throughout a larger area of the galaxy than current star formation. As the AGN at the center of NGC 1266 continues to drive cold gas out of the galaxy, we expect star formation rates to decline as the star formation is ultimately quenched. Thus, NGC 1266 is in the midst of a key portion of its evolution and continued studies of this unique galaxy may help improve our understanding of how galaxies transition from the blue to the red sequence (Alatalo et al. 2011)., Comment: 1 page, Proceedings IAU symposium No. 292: Molecular gas, dust and star formation in galaxies, ed. by Tony Wong and Juergen Ott
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- 2013
37. Starbursts in and out of the star-formation main sequence.
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Elbaz, D., Leiton, R., Nagar, N., Okumura, K., Franco, M., Schreiber, C., Pannella, M., Wang, T., Dickinson, M., Díaz-Santos, T., Ciesla, L., Daddi, E., Bournaud, F., Magdis, G., Zhou, L., and Rujopakarn, W.
- Subjects
STARBURSTS ,STAR formation ,MAIN sequence (Astronomy) ,GALACTIC evolution - Abstract
Aims. We use high-resolution continuum images obtained with the Atacama Large Millimeter Array (ALMA) to probe the surface density of star formation in z ~ 2 galaxies and study the different physical properties between galaxies within and above the star-formation main sequence of galaxies. Methods. We use ALMA images at 870 μm with 0.2 arcsec resolution in order to resolve star formation in a sample of eight star-forming galaxies at z ~ 2 selected among the most massive Herschel galaxies in the GOODS-South field. This sample is supplemented with eleven galaxies from the public data of the 1.3 mm survey of the Hubble Ultra-Deep Field, HUDF. We derive dust and gas masses for the galaxies, compute their depletion times and gas fractions, and study the relative distributions of rest-frame ultraviolet (UV) and far-infrared (FIR) light. Results. ALMA reveals systematically dense concentrations of dusty star formation close to the center of the stellar component of the galaxies. We identify two different starburst regimes: (i) the classical population of starbursts located above the SFR-M⋆ main sequence, with enhanced gas fractions and short depletion times and (ii) a sub-population of galaxies located within the scatter of the main sequence that experience compact star formation with depletion timescales typical of starbursts of ~150 Myr. In both starburst populations, the FIR and UV are distributed in distinct regions and dust-corrected star formation rates (SFRs) estimated using UV-optical-near-infrared data alone underestimate the total SFR. Starbursts hidden in the main sequence show instead the lowest gas fractions of our sample and could represent the last stage of star formation prior to passivization. Being Herschel-selected, these main sequence galaxies are located in the high-mass end of the main sequence, hence we do not know whether these "starbursts hidden in the main sequence" also exist below 10
11 M⊙ . Active galactic nuclei (AGNs) are found to be ubiquitous in these compact starbursts, suggesting that the triggering mechanism also feeds the central black hole or that the active nucleus triggers star formation. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
38. A molecular gas-rich GRB host galaxy at the peak of cosmic star formation.
- Author
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Arabsalmani, M., Le Floc'h, E., Dannerbauer, H., Feruglio, C., Daddi, E., Ciesla, L., Charmandaris, V., Japelj, J., Vergani, S. D., Duc, P.-A., Basa, S., Bournaud, F., and Elbaz, D.
- Subjects
GAMMA ray bursts ,EMISSION-line galaxies ,MOLECULAR gas lasers ,STAR formation ,REDSHIFT - Abstract
We report the detection of the CO(3-2) emission line from the host galaxy of gamma-ray burst (GRB) 080207 at z=2.086. This is the first detection of molecular gas in emission from a GRB host galaxy beyond redshift 1. We find this galaxy to be rich in molecular gas with a mass of 1.1 x 10
11 M⊙ assuming αCO = 4.36 M⊙ (K km s-1 pc²)-1 . The molecular gas mass fraction of the galaxy is ~0.5, typical of star-forming galaxies (SFGs) with similar stellar masses and redshifts. With an SFRFIR of 260 M⊙ yr-1 , we measure a molecular gas depletion time-scale of 0.43 Gyr, near the peak of the depletion time-scale distribution of SFGs at similar redshifts. Our findings are therefore in contradiction with the proposed molecular gas deficiency in GRB host galaxies. We argue that the reported molecular gas deficiency for GRB hosts could be the artefact of improper comparisons or neglecting the effect of the typical low metallicities of GRB hosts on the CO-to-molecular-gas conversion factor. We also compare the kinematics of the CO(3-2) emission line to that of the Hα emission line from the host galaxy. We find the Hα emission to have contributions from two separate components, a narrow and a broad one. The narrow component matches the CO emission well in velocity space. The broad component, with a full width at half-maximum of ~1100 km s-1 , is separated by +390 km s-1 in velocity space from the narrow component. We speculate this broad component to be associated with a powerful outflow in the host galaxy or in an interacting system. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
39. Morphology and enhanced star formation in a Cartwheel-like ring galaxy.
- Author
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Renaud, F., Athanassoula, E., Amram, P., Bosma, A., Bournaud, F., Duc, P. -A., Epinat, B., Fensch, J., Kraljic, K., Perret, V., and Struck, C.
- Subjects
STAR formation ,CARTWHEEL (Galaxy) ,DISK galaxies ,STAR clusters ,SUPERGIANT stars - Abstract
We use hydrodynamical simulations of a Cartwheel-like ring galaxy, modelled as a nearly head-on collision of a small companion with a larger disc galaxy, to probe the evolution of the gaseous structures and flows, and to explore the physical conditions setting the star formation activity. Star formation is first quenched by tides as the companion approaches, before being enhanced shortly after the collision. The ring ploughs the disc material as it radially extends, and almost simultaneously depletes its stellar and gaseous reservoir into the central region, through the spokes, and finally dissolve 200 Myr after the collision. Most of star formation first occurs in the ring before this activity is transferred to the spokes and then the nucleus.We thus propose that the location of star formation traces the dynamical stage of ring galaxies, and could help constrain their star formation histories. The ring hosts tidal compression associated with strong turbulence. This compression yields an azimuthal asymmetry, with maxima reached in the side furthest away from the nucleus, which matches the star formation activity distribution in our models and in observed ring systems. The interaction triggers the formation of star clusters significantly more massive than before the collision, but less numerous than in more classical galaxy interactions. The peculiar geometry of Cartwheel-like objects thus yields a star (cluster) formation activity comparable to other interacting objects, but with notable second order differences in the nature of turbulence, the enhancement of the star formation rate, and the number of massive clusters formed. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
40. PHIBSS: molecular gas content and scaling relations in z~1-3 normal star forming galaxies
- Author
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Tacconi, L. J., Neri, R., Genzel, R., Combes, F., Bolatto, A., Cooper, M. C., Wuyts, S., Bournaud, F., Burkert, A., Comerford, J., Cox, P., Davi, M., Schreiber, N. M. F��rster, Garc��a-Burillo, S., Gracia-Carpio, J., Lutz, D., Naab, T., Newman, S., Omont, A., Saintonge, A., Griffin, K. Shapiro, Shapley, A., Sternberg, A., and Weiner, B.
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,FOS: Physical sciences ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present PHIBSS, the IRAM Plateau de Bure high-z blue sequence CO 3-2 survey of the molecular gas properties in normal star forming galaxies (SFGs) near the cosmic star formation peak. PHIBSS provides 52 CO detections in two redshift slices at z~1.2 and 2.2, with log(M*(M_solar))>10.4 and log(SFR(M_solar/yr))>1.5. Including a correction for the incomplete coverage of the M*-SFR plane, we infer average gas fractions of ~0.33 at z~1.2 and ~0.47 at z~2.2. Gas fractions drop with stellar mass, in agreement with cosmological simulations including strong star formation feedback. Most of the z~1-3 SFGs are rotationally supported turbulent disks. The sizes of CO and UV/optical emission are comparable. The molecular gas - star formation relation for the z=1-3 SFGs is near-linear, with a ~0.7 Gyrs gas depletion timescale; changes in depletion time are only a secondary effect. Since this timescale is much less than the Hubble time in all SFGs between z~0 and 2, fresh gas must be supplied with a fairly high duty cycle over several billion years. At given z and M*, gas fractions correlate strongly with the specific star formation rate. The variation of specific star formation rate between z~0 and 3 is mainly controlled by the fraction of baryonic mass that resides in cold gas., Submitted to the Astrophysical Journal; 14 figures
- Published
- 2012
41. Volume Rendering of AMR Simulations
- Author
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Labadens, M., Pomarède, D., Chapon, D., Romain Teyssier, Bournaud, F., Renaud, F., and Grandjouan, N.
- Subjects
FOS: Computer and information sciences ,Computer Science - Data Structures and Algorithms ,Data Structures and Algorithms (cs.DS) - Abstract
High-resolution simulations often rely on the Adaptive Mesh Resolution (AMR) technique to optimize memory consumption versus attainable precision. While this technique allows for dramatic improvements in terms of computing performance, the analysis and visualization of its data outputs remain challenging. The lack of effective volume renderers for the octree-based AMR used by the RAMSES simulation program has led to the development of the solutions presented in this paper. Two custom algorithms are discussed, based on the splatting and the ray-casting techniques. Their usage is illustrated in the context of the visualization of a high-resolution, 6000-processor simulation of a Milky Way-like galaxy. Performance obtained in terms of memory management and parallelism speedup are presented.
- Published
- 2012
42. Probing the mass assembly of massive nearby galaxies with deep imaging
- Author
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Duc, P. -A, Cuillandre, J. -C, Alatalo, K., Blitz, L., Bois, M., Bournaud, F., Bureau, M., Cappellari, M., Côté, P., Davies, R. L., Davis, T. A., de Zeeuw, P. T., Emsellem, E., Ferrarese, L., Ferriere, E., Gwyn, S., Khochfar, S., Krajnovic, D., Kuntschner, H., Lablanche, P. -Y, McDermid, R. M., Michel-Dansac, L., Morganti, R., Naab, T., Oosterloo, T., Sarzi, M., Scott, N., Serra, P., Weijmans, A., Young, L. M., Thomas, Daniel, Pasquali, Anna, Ferreras, Ignacio, and Astronomy
- Subjects
Physics ,Effective radius ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Stellar mass ,FOS: Physical sciences ,Perturbation (astronomy) ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Galaxy ,Redshift ,Accretion (astrophysics) ,cD ,Space and Planetary Science ,galaxies: interactions ,Astrophysics::Solar and Stellar Astrophysics ,Surface brightness ,Halo ,Astrophysics::Earth and Planetary Astrophysics ,galaxies: elliptical and lenticular ,galaxies: evolution ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
According to a popular scenario supported by numerical models, the mass assembly and growth of massive galaxies, in particular the Early-Type Galaxies (ETGs), is, below a redshift of 1, mainly due to the accretion of multiple gas-poor satellites. In order to get observational evidence of the role played by minor dry mergers, we are obtaining extremely deep optical images of a complete volume limited sample of nearby ETGs. These observations, done with the CFHT as part of the ATLAS3D, NGVS and MATLAS projects, reach a stunning 28.5 - 29 mag.arcsec-2 surface brightness limit in the g' band. They allow us to detect the relics of past collisions such as faint stellar tidal tails as well as the very extended stellar halos which keep the memory of the last episodes of galactic accretion. Images and preliminary results from this on-going survey are presented, in particular a possible correlation between the fine structure index (which parametrizes the amount of tidal perturbation) of the ETGs, their stellar mass, effective radius and gas content., International Astronomical Union Symposium 295: The intriguing life of massive galaxies, August 27-31, 2012, Beijing, China
- Published
- 2012
43. The ATLAS project - XII. Recovery of the mass-to-light ratio of simulated early-type barred galaxies with axisymmetric dynamical models
- Author
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Lablanche, P, Cappellari, M, Emsellem, E, Bournaud, F, Michel-Dansac, L, Alatalo, K, Blitz, L, Bois, M, Bureau, M, Davies, R, Davis, T, de Zeeuw, P, Duc, P, Khochfar, S, Krajnovic, D, Kuntschner, H, Morganti, R, McDermid, R, Naab, T, Oosterloo, T, Sarzi, M, Scott, N, Serra, P, Weijmans, A, and Young, L
- Subjects
Astrophysics::Cosmology and Extragalactic Astrophysics - Abstract
We investigate the accuracy in the recovery of the stellar dynamics of barred galaxies when using axisymmetric dynamical models. We do this by trying to recover the mass-to-light ratio (M/L) and the anisotropy of realistic galaxy simulations using the Jeans Anisotropic Multi-Gaussian Expansion (JAM) modelling method. However, given that the biases we find are mostly due to an application of an axisymmetric modelling algorithm to a non-axisymmetric system and in particular to inaccuracies in the deprojected mass model, our results are relevant for general axisymmetric modelling methods. We run N-body collisionless simulations to build a library with various luminosity distribution, constructed to mimic real individual galaxies, with realistic anisotropy. The final result of our evolved library of simulations contains both barred and unbarred galaxies. The JAM method assumes an axisymmetric mass distribution, and we adopt a spatially constant M/L and anisotropy distributions. The models are fitted to two-dimensional maps of the second velocity moments of the simulations for various viewing angles [position angle (PA) of the bar and inclination of the galaxy]. We find that the inclination is generally well recovered by the JAM models, for both barred and unbarred simulations. For unbarred simulations the M/L is also accurately recovered, with negligible median bias and with a maximum one of just Δ(M/L) < 1.5 per cent when the galaxy is not too close to face on. At very low inclinations the M/L can be significantly overestimated (9 per cent in our tests, but errors can be larger for very face-on views). This is in agreement with previous studies. For barred simulations the M/L is on average (when PA = 45°) essentially unbiased, but we measure an over/underestimation of up to Δ(M/L) = 15 per cent in our tests. The sign of the M/L bias depends on the PA of the bar as expected: overestimation occurs when the bar is closer to end-on, due to the increased stellar motion along the line-of-sight, and underestimation otherwise. For unbarred simulations, the JAM models are able to recover the mean value of the anisotropy with bias, within the region constrained by the kinematics. However when a bar is present, or for nearly face-on models, the recovered anisotropy varies wildly, with biases up to Δβ z≈ 0.3. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.
- Published
- 2012
44. GOODS-Herschel: the far-infrared view of star formation in active galactic nucleus host galaxies since z similar to 3
- Author
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Mullaney, JR, Pannella, M, Daddi, E, Alexander, DM, Elbaz, D, Hickox, RC, Bournaud, F, Altieri, B, Aussel, H, Coia, D, Dannerbauer, H, Dasyra, K, Dickinson, M, Hwang, HS, Kartaltepe, J, Leiton, R, Magdis, G, Magnelli, B, Popesso, P, Valtchanov, I, Bauer, FE, Brandt, WN, Del Moro, A, Hanish, DJ, Ivison, RJ, Juneau, S, Luo, B, Lutz, D, Sargent, MT, Scott, D, and Xue, YQ
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
We present a study of the infrared properties of X-ray selected, moderate-luminosity (i.e.LX= 1042-1044ergs-1) active galactic nuclei (AGNs) up toz≈ 3, in order to explore the links between star formation in galaxies and accretion on to their central black holes. We use 100 and 160μ mfluxes from GOODS-Herschel- the deepest survey yet undertaken by theHerscheltelescope - and show that in the vast majority of cases (i.e. >94percent) these fluxes are dominated by emission from the host galaxy. As such, these far-infrared bands provide an uncontaminated view of star formation in the AGN host galaxies. We find no evidence of any correlation between the X-ray and infrared luminosities of moderate AGNs at any redshift, suggesting that global star formation is decoupled from nuclear (i.e. AGN) activity in these galaxies. On the other hand, we confirm that the star formation rates of AGN hosts increase strongly with redshift, by a factor of 43+27- 18 fromz< 0.1 toz= 2-3 for AGNswith the same range of X-ray luminosities. This increase is entirely consistent with the factor of 25-50 increase in the specific star formation rates (SSFRs) of normal, star-forming (i.e. main-sequence) galaxies over the same redshift range. Indeed, the average SSFRs of AGN hosts are only marginally (i.e. ≈20percent) lower than those of main-sequence galaxies at all surveyed redshifts, with this small deficit being due to a fraction of AGNs residing in quiescent (i.e. low SSFR) galaxies. We estimate that 79 ± 10percent of moderate-luminosity AGNs are hosted in main-sequence galaxies, 15 ± 7percent in quiescent galaxies and
- Published
- 2012
45. ATLAS3D project. IV. (Young+, 2011)
- Author
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Young, L. M., Bureau, M., Davis, T. A., Combes, F., McDermid, R. M., Alatalo, K., Blitz, L., Bois, M., Bournaud, F., Cappellari, M., Davies, R. L., de Zeeuw, P. T., Emsellem, E., Khochfar, S., Krajnovic, D., Kuntschner, H., Lablanche, P. -Y, Morganti, R., Naab, T., Oosterloo, T., Sarzi, M., Scott, N., Serra, P., Weijmans, A. -M, and Astronomy
- Subjects
Surveys ,Carbon monoxide ,Galaxy catalogs ,Spectroscopy - Abstract
The IRAM 30-m telescope at Pico Veleta, Spain, was used for simultaneous observations of the 12CO(1-0) and (2-1) emission during 2007 July, 2008 March and 2008 November. (2 data files).
- Published
- 2012
46. The ATLAS 3D project - VI. Simulations of binary galaxy mergers and the link with fast rotators, slow rotators and kinematically distinct cores
- Author
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Bois, M, Emsellem, E, Bournaud, F, Alatalo, K, Blitz, L, Bureau, M, Cappellari, M, Davies, R, Davis, T, de Zeeuw, P, Duc, P, Khochfar, S, Krajnović, D, Kuntschner, H, Lablanche, P, McDermid, R, Morganti, R, Naab, T, Oosterloo, T, Sarzi, M, Scott, N, Serra, P, Weijmans, A, Young, L, Astronomy, and Kapteyn Astronomical Institute
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,EFFECTIVE RADII ,FOS: Physical sciences ,DISK GALAXIES ,BULGE FORMATION ,Astrophysics::Cosmology and Extragalactic Astrophysics ,SAURON PROJECT ,methods: numerical ,DARK-MATTER HALOES ,ELLIPTIC GALAXIES ,galaxies: elliptical and lenticular, cD ,galaxies: interactions ,STAR-FORMING GALAXIES ,galaxies: formation ,ORBITAL STRUCTURE ,COMPACT SPHEROIDS ,SPIRAL GALAXIES ,galaxies: kinematics and dynamics ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We study the formation of early-type galaxies through mergers with a sample of 70 high-resolution (softening length < 60 pc and 12*10^6 particles) numerical simulations of binary mergers of disc galaxies and 16 simulations of ETG remergers. These simulations, designed to accompany observations and models conducted within the Atlas3D project, encompass various mass ratios (from 1:1 to 6:1), initial conditions and orbital parameters. The progenitor disc galaxies are spiral-like with bulge to disc ratios typical of Sb and Sc galaxies. We find that binary mergers of disc galaxies with mass ratios of 3:1 and 6:1 are nearly always classified as Fast Rotators according to the Atlas3D criterion (based on the lambda_R parameter): they preserve the structure of the input fast rotating spiral progenitors. They have intrinsic ellipticities larger than 0.5, cover intrinsic lambda_R values between 0.2 and 0.6, within the range of observed Fast Rotators. Major disc mergers (mass ratios of 2:1 and 1:1) lead to both Fast and Slow Rotators. Most of the Fast Rotators produced in major mergers have intermediate flattening, with ellipticities between 0.4 and 0.6. Most Slow Rotators formed in these binary disc mergers hold a stellar Kinematically Distinct Core (KDC) in their 1-3 central kilo-parsec: these KDCs are built from the stellar components of the progenitors. Besides a handful of specific observed systems -- the counter-rotating discs (2-sigma galaxies) -- these therefore cannot reproduce the observed population of Slow Rotators in the nearby Universe. The mass ratio of the progenitors is a fundamental parameter for the formation of Slow Rotators in these binary mergers, but it also requires a retrograde spin for the earlier-type (Sb) progenitor galaxy with respect to the orbital angular momentum. (Abridged), Accepted for publication by MNRAS
- Published
- 2011
47. GOODS-Herschel: The far-infrared view of star formation in AGN host galaxies since z~3
- Author
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Mullaney, J. R., Pannella, M., Daddi, Emanuele, Alexander, D. M., Elbaz, D., Hickox, R. C., Bournaud, F., Altieri, B., Aussel, H., Coia, D., Dannerbauer, H., Dasyra, K., Dickinson, M., Hwang, H. S., Kartaltepe, J., Leiton, R., Magdis, G., Magnelli, B., Popesso, P., Valtchanov, I., Bauer, F. E., Brandt, W. N., del Moro, A., Hanish, D. J., Ivison, R. J., Juneau, S., Luo, B., Lutz, D., Sargent, M. T., Scott, D., Xue, Y. Q., 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), Department of Physics, Durham University, Herschel Science Centre, European Space Agency (ESA), NOAO, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Extraterrestrische Physik (MPE), Departamento de Astronomía y Astrofísica [Santiago], Pontificia Universidad Católica de Chile (UC), Department of Astronomy and Astrophysics [PennState], Pennsylvania State University (Penn State), Penn State System-Penn State System, Infrared Processing and Analysis Center, California Institute of Technology (CALTECH), Royal Observatory Edinburgh (ROE), University of Edinburgh, Steward observatory, University of Arizona, Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Department of Physics and Astronomy [Vancouver], University of British Columbia (UBC), UPGAL, European Project: 240039,EC:FP7:ERC,ERC-2009-StG,UPGAL(2009), 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), Agence Spatiale Européenne = European Space Agency (ESA), National Optical Astronomy Observatory (NOAO), 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), Infrared Processing and Analysis Center (IPAC), Harvard University-Smithsonian Institution, and Smithsonian Institution-Harvard University [Cambridge]
- Subjects
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present a study of the infrared properties of X-ray selected, moderate luminosity (Lx=10^{42}-10^{44}ergs/s) active galactic nuclei (AGNs) up to z~3, to explore the links between star formation in galaxies and accretion onto their central black holes. We use 100um and 160um fluxes from GOODS-Herschel -the deepest survey yet undertaken by the Herschel telescope- and show that in >94 per cent of cases these fluxes are dominated by the host. We find no evidence of any correlation between the X-ray and infrared luminosities of moderate AGNs at any redshift, suggesting that star-formation is decoupled from nuclear (AGN) activity. The star formation rates of AGN hosts increase strongly with redshift; by a factor of 43 from z20 per cent at Mstars>10^{11}Msun. Our results indicate that it is galaxy stellar mass that is most important in dictating whether a galaxy hosts a moderate luminosity AGN. We argue that the majority of moderate nuclear activity is fuelled by internal mechanisms rather than violent mergers, suggesting that disk instabilities could be an important AGN feeding mechanism., 21 pages; 14 Figures; MNRAS accepted; some figures have been degraded, full resolution version at: http://tinyurl.com/JMullaney2011
- Published
- 2011
48. The metallicity dependence of the CO {\rightarrow} H_2 conversion factor in z>1 star forming galaxies
- Author
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Genzel, R., Tacconi, L. J., Combes, F., Bolatto, A., Neri, R., Sternberg, A., Cooper, M. C., Bouche, N., Bournaud, F., Burkert, A., Comerford, J., Cox, P., Davis, M., Schreiber, N. M. Foerster, Garcia-Burillo, S., Gracia-Carpio, J., Lutz, D., Naab, T., Newman, S., Saintonge, A., Shapiro, K., Shapley, A., and Weiner, B.
- Subjects
Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We use the first systematic samples of CO millimeter emission in z>1 'main-sequence' star forming galaxies (SFGs) to study the metallicity dependence of the conversion factor {\alpha}CO, from CO line luminosity to molecular gas mass. The molecular gas depletion rate inferred from the ratio of the star formation rate (SFR) to CO luminosity, is ~1 Gyr-1 for near-solar metallicity galaxies with stellar masses above M_S~1e11 M_sun. In this regime the depletion rate does not vary more than a factor of two to three as a function of molecular gas surface density, or redshift between z~0 and 2. Below M_S the depletion rate increases rapidly with decreasing metallicity. We argue that this trend is not caused by starburst events, by changes in the physical parameters of the molecular clouds, or by the impact of the fundamental metallicity-SFR-stellar mass relation. A more probable explanation is that the conversion factor is metallicity dependent and that star formation can occur in 'CO-dark' gas. The trend is also expected theoretically from the effect of enhanced photodissociation of CO by ultraviolet radiation at low metallicity. From the available z~0 and z~1-3 samples we constrain the slope of the log({\alpha}CO) -log (metallicity) relation to range between -1 and -2, fairly insensitive to the assumed slope of the gas-star formation rate relation. Because of the lower metallicities near the peak of the galaxy formation activity at z~1-2 compared to z~0, we suggest that molecular gas masses estimated from CO luminosities have to be substantially corrected upward for galaxies below M_S., Comment: ApJ in press
- Published
- 2011
49. Molecular Gas and Star Formation in Local Early-type Galaxies
- Author
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Bureau, M., Davis, T. A., Alatalo, K., Crocker, A. F., Blitz, L., Young, L. M., Combes, F., Bois, M., Bournaud, F., Cappellari, M., Davies, R. L., de Zeeuw, P. T., Duc, P. -A, Emsellem, E., Khochfar, S., Krajnović, D., Kuntschner, H., Lablanche, P. -Y, McDermid, R. M., Morganti, R., Naab, T., Oosterloo, T., Sarzi, M., Scott, N., Serra, P., Weijmans, A., Carignan, Claude, Combes, François, Freeman, Ken C., and Astronomy
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Field (physics) ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,cD ,Luminosity ,ISM: evolution ,Cluster (physics) ,galaxies: elliptical and lenticular ,galaxies: kinematics and dynamics ,Astrophysics::Galaxy Astrophysics ,ISM: kinematics and dynamics ,Physics ,Star formation ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,ISM: molecules ,Galaxy ,Early type ,Stars ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Detection rate ,galaxies: evolution ,galaxies: ISM ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
The molecular gas content of local early-type galaxies is constrained and discussed in relation to their evolution. First, as part of the Atlas3D survey, we present the first complete, large (260 objects), volume-limited single-dish survey of CO in normal local early-type galaxies. We find a surprisingly high detection rate of 22%, independent of luminosity and at best weakly dependent on environment. Second, the extent of the molecular gas is constrained with CO synthesis imaging, and a variety of morphologies is revealed. The kinematics of the molecular gas and stars are often misaligned, implying an external gas origin in over a third of the systems, although this behaviour is drastically diffferent between field and cluster environments. Third, many objects appear to be in the process of forming regular kpc-size decoupled disks, and a star formation sequence can be sketched by piecing together multi-wavelength information on the molecular gas, current star formation, and young stars. Last, early-type galaxies do not seem to systematically obey all our usual prejudices regarding star formation, following the standard Schmidt-Kennicutt law but not the far infrared-radio correlation. This may suggest a greater diversity in star formation processes than observed in disk galaxies. Using multiple molecular tracers, we are thus starting to probe the physical conditions of the cold gas in early-types., Proceedings of the IAU Symposium 277 "Tracing the Ancestry of Galaxies". 4 pages, 3 figures
- Published
- 2011
50. Early-type Galaxies in Isolation: An HI Perspective with ATLAS 3D
- Author
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Serra, P., Morganti, R., Oosterloo, T. A., Alatalo, K., Blitz, L., Bois, M., van den Bosch, R. C. E., Bournaud, F., Bureau, M., Cappellari, M., Davies, R. L., Davis, T. A., Duc, P., Emsellem, E., Falcón-Barroso, J., Khochfar, S., Krajnovic, D., Kuntschner, H., Lablanche, P. Y., McDermid, R. M., Naab, T., Sarzi, M., Scott, N., de Ven, G., Weijmans, A., Young, L. M., de Zeeuw, P. T., Verder-Montenegro, L., del Olmo, A., Sulentic, J., and Kapteyn Astronomical Institute
- Abstract
We present preliminary results of our HI WSRT observations of early-type galaxies in the ATLAS3D sample. We discuss the dependence of HI properties on environment. We detect HI in about half of the galaxies outside the Virgo cluster. The HI morphology/kinematics changes as a function of environment, going from regular, rotating systems around “isolated” galaxies to progressively more disturbed structures for galaxies with neighbours or in groups. In denser environment, inside Virgo, nearly none of the galaxies contains HI.
- Published
- 2010
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