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Start Over Author "Lefevre, O." Topic astrophysics (astro-ph)
5 results on '"Lefevre, O."'

1. The H$��$ Luminosity Function and Star Formation Rate at $z \approx 0.24$ in the Cosmos 2 Square-Degree Field

Author

Shioya, Y., Taniguchi, Y., Sasaki, S. S., Nagao, T., Murayama, T., Takahashi, M. I., Ajiki, M., Ideue, Y., Mihara, S., Nakajima, A., Scoville, N. Z., Mobasher, B., Aussel, H., Giavalisco, M., Guzzo, L., Hasinger, G., Impey, C., LeFevre, O., Lilly, S., Renzini, A., Rich, M., Sanders, D. B., Schinnerer, E., Shopbell, P., Leauthaud, A., Kneib, J. -P., Rhodes, J., and Massey, R.

Subjects
Astrophysics (astro-ph), FOS: Physical sciences
Abstract

To derive a new H$��$ luminosity function and to understand the clustering properties of star-forming galaxies at $z \approx 0.24$, we have made a narrow-band imaging survey for H$��$ emitting galaxies in the HST COSMOS 2 square degree field. We used the narrow-band filter NB816 ($��_c = 8150$ ��, $����= 120$ ��) and sampled H$��$ emitters with $EW_{\rm obs}(\rm H��+ [N\textsc{ii}]) > 12$ ��in a redshift range between $z=0.233$ and $z=0.251$ corresponding to a depth of 70 Mpc. We obtained 980 H$��$ emitting galaxies in a sky area of 5540 arcmin$^2$, corresponding to a survey volume of $3.1 \times 10^4 {\rm Mpc^3}$. We derive a H$��$ luminosity function with a best-fit Schechter function parameter set of $��= -1.35^{+0.11}_{-0.13}$, $\log��_* = -2.65^{+0.27}_{-0.38}$, and $\log L_* ({\rm erg s^{-1}}) = 41.94^{+0.38}_{-0.23}$. The H$��$ luminosity density is $2.7^{+0.7}_{-0.6} \times 10^{39}$ ergs s$^{-1}$ Mpc$^{-3}$. After subtracting the AGN contribution (15 %) to the H$��$ luminosity density, the star formation rate density is evaluated as $1.8^{+0.7}_{-0.4} \times 10^{-2}$ $M_{\sun}$ yr$^{-1}$ Mpc$^{-3}$. The angular two-point correlation function of H$��$ emitting galaxies of $\log L({\rm H��}) > 39.8$ is well fit by a power law form of $w(��) = 0.013^{+0.002}_{-0.001} ��^{-0.88 \pm 0.03}$, corresponding to the correlation function of $��(r) = (r/1.9{\rm Mpc})^{-1.88}$. We also find that the H$��$ emitters with higher H$��$ luminosity are more strongly clustered than those with lower luminosity., 13 pages, 9 fifgure, to apper in ApJS

Published
2007
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2. An Integral Field Spectrograph for SNAP Supernova Identification

Author

Ealet, A., Prieto, E., Bonissent, A., Malina, R., Bernstein, G., Basa, S., Lefevre, O., Mazure, A., Bonneville, C., Akerlof, C., Aldering, G., Amanullah, R., Astier, P., Barrelet, E., Bebek, C., Bergstrom, L., Bercovitz, J., Bester, M., Bower, C., Carithers, W., Commins, E., Day, C., Deustua, S., Digennaro, R., Ellis, R., Eriksson, M., Fruchter, A., Genat, J. F., Goldhaber, G., Goobar, A., Groom, Donald E., Harris, S., Harvey, P., Heetderks, H., Holland, S., Huterer, D., Karcher, A., Kim, A., Kolbe, W., Krieger, B., Lafever, R., Lamoureux, J., Lampton, M., Levi, M., Levin, D., Linder, E., Loken, S., Massey, R., Mckay, T., Mckee, S., Ramon Miquel, Mortsell, E., Mostek, N., Mufson, Stuart L., Musser, J., Nugent, P., Oluseyi, H., Pain, R., Palaio, N., Pankow, D., Perlmutter, S., Pratt, R., Refregier, A., Rhodes, J., Robinson, K., Roe, N., Sholl, M., Schubnell, M., Smadja, G., Smoot, George F., Spadafora, A., Tarle, G., Tomasch, A., Lippe, H., Vincent, D., Walder, J. P., Wang, G., 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), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), John C. Mather, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

A well-adapted spectrograph concept has been developed for the SNAP (SuperNova/Acceleration Probe) experiment. The goal is to ensure proper identification of Type Ia supernovae and to standardize the magnitude of each candidate by determining explosion parameters. An instrument based on an integral field method with the powerful concept of imager slicing has been designed and is presented in this paper. The spectrograph concept is optimized to have very high efficiency and low spectral resolution (R~100), constant through the wavelength range (0.35-1.7 microns), adapted to the scientific goals of the mission., Comment: This paper will be published in SPIE Proceedings Vol. 4850 and is made available as an electronic preprint with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited

Published
2002
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3. MIFS: A Mega Integral Field Spectrograph for the VLT

Author

Bacon, R., Adam, G., Cabrit, S., Combes, F., Davies, R. L., Emsellem, E., Ferruit, P., Franx, M., Gilmore, G., Guiderdoni, B., Lefevre, O., Morris, S., Pecontal, E., Prieto, E., Sharples, R., van der Werf, P., and de Zeeuw, P. T.

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

We describe MIFS, a second generation integral-field spectrograph for the VLT, operating in the visible wavelength range. It combines a 1'x1' field of view with the improved spatial resolution provided by multi-conjugate adaptive optics and covers a large simultaneous spectral range (0.6-1.0 microns). A separate mode exploits the highest spatial resolution provided by adaptive optics. With this unique combination of capabilities, MIFS has a wide domain of application and a large discovery potential. The MIFS low-spatial resolution mode (sampled at 0.2") combined with the initial MCAO capabilities planned for the VLT will provide ultra-deep fields with a limiting magnitude for spectroscopy of R~28. MIFS will improve the present day detection limit of Lyman alpha emitters by a factor of 100, and will detect low-mass star-forming galaxies to z~7. The MIFS high-spatial resolution mode (3"x3" field sampled at 0.01") is optimized for the next step in (MC)AO. It will probe, e.g., the relationship between supermassive central black holes and their host galaxy and the physics of winds from accretion disks in young stellar objects at unprecedented spatial resolution. MIFS will extend Europe's lead in integral-field spectroscopy. It capitalizes on new developments in adaptive optics, and is a key step towards instrumentation for OWL., 10 pages, 2 figures June 2001 ESO workshop on "Scientific Drivers for ESO Future VLT/VLTI Instrumentation"

Published
2001

4. The Environments of Active Galactic Nuclei within the zCOSMOS Density Field

Author

O. Cucciati, Pascal Oesch, S. de la Torre, R. Pello, M. Mignoli, P. Kampczyk, C. M. Carollo, F. Lamareille, D. Bottini, Andrea Comastri, J. F. Le Borgne, Graziano Coppa, E. Zucca, E. Ricciardelli, Marco Scodeggio, S. Bardelli, Christian Maier, T. Contini, Knud Jahnke, Mara Salvato, Vincenzo Mainieri, E. Perez Montero, H. J. McCracken, Roberto Gilli, M. Elvis, P. Memeo, Jean-Paul Kneib, Christian Marinoni, Richard E. Griffiths, A. Finoguenov, L. Tresse, P. Franzetti, A. Cappi, Paolo Cassata, D. Vergani, C. Knobel, G. Hasinger, Angela Bongiorno, John D. Silverman, G. Zamorani, L. de Ravel, O. Le Fevre, Francesca Civano, B. Garilli, Y. Peng, Katarina Kovac, V. Le Brun, Nico Cappelluti, Masaomi Tanaka, M. Bolzonella, Cristian Vignali, Karina Caputi, L. A. M. Tasca, Fabrizio Fiore, Hermann Brunner, S. J. Lilly, M. Fumana, Cristiano Porciani, A. Iovino, B. Meneux, Marcella Brusa, Institute of Astronomy [ETH Zürich], Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), INAF - Osservatorio Astronomico di Bologna (OABO), Istituto Nazionale di Astrofisica (INAF), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), 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), European Southern Observatory (ESO), Max-Planck-Institut für Extraterrestrische Physik (MPE), 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), Universitats-Sternwarte [München], Ludwig-Maximilians-Universität München (LMU), INAF - Osservatorio Astronomico di Brera (OAB), INAF - Osservatorio Astronomico di Roma (OAR), INAF-IASF Milano, Carnegie Mellon University [Pittsburgh] (CMU), Space Telescope Science Institute (STSci), Universita degli Studi di Padova, Dipartimento di Astronomia, Universita degli Studi di Bologna, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Centre de Physique Théorique - UMR 7332 (CPT), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), California Institute of Technology (CALTECH), Silverman J. D., Kovac K., Knobel C., Lilly S., Bolzonella M., Lamareille F., Mainieri V., Brusa M., Cappelluti N., Peng Y., Hasinger G., Zamorani G., Scodeggio M., Contini T., Carollo C. M., Jahnke K., Kneib J.-P., LeFevre O., Bardelli S., Bongiorno A., Brunner H., Caputi K., Civano F., Comastri A., Coppa G., Cucciati O., de la Torre S., de Ravel L., Elvis M., Finoguenov A., Fiore F., Franzetti P., Garilli B., Gilli R., Griffiths R., Iovino A., Kampczyk P., Koekemoer A., LeBorgne J.-F., LeBrun V., Maier C., Mignoli M., Pello R., Perez Montero E., Ricciardelli E., Tanaka M., Tasca L., Tresse L., Vergani D., Vignali C., Zucca E., Bottini D., Cappi A., Cassata P., Marinoni C., McCracken H. J., Memeo P., Meneux B., Oesch P., Porciani C., Salvato M., AUTRES, Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées (LATT), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, University of Chicago, Max-Planck-Institut für Astronomie (MPIA), INAF- Milano, INAF - Osservatorio Astronomico di Capodimonte (OAC), UPRESA, Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2, Department of Statistics [Oxford], University of Oxford [Oxford], Services communs OMP (UMS 831), Glycosciences Laboratory, Imperial College School of Medicine, Information Science Laboratory, Tokai University, Japan Atomic Energy Agency, Centre de Physique Théorique - UMR 6207 (CPT), Université de la Méditerranée - Aix-Marseille 2-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Università degli Studi di Padova = University of Padua (Unipd)

Subjects
Active galactic nucleus, Stellar mass, Galaxies: active, Quasars: general, X-rays: galaxies, Astronomy and Astrophysics, Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, Population, galaxies: active, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], quasars: general, 0103 physical sciences, Density field, education, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, education.field_of_study, 010308 nuclear & particles physics, Star formation, Astrophysics (astro-ph), Significant difference, Redshift survey, Galaxy, Astrophysics::Earth and Planetary Astrophysics, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], galaxies: active – quasars: general – X-rays: galaxies
Abstract

The impact of environment on AGN activity up to z~1 is assessed by utilizing a mass-selected sample of galaxies from the 10k catalog of the zCOSMOS spectroscopic redshift survey. We identify 147 AGN by their X-ray emission as detected by XMM-Newton from a parent sample of 7234 galaxies. We measure the fraction of galaxies with stellar mass M_*>2.5x10^10 Msun that host an AGN as a function of local overdensity using the 5th, 10th and 20th nearest neighbors that cover a range of physical scales (~1-4 Mpc). Overall, we find that AGNs prefer to reside in environments equivalent to massive galaxies with substantial levels of star formation. Specifically, AGNs with host masses between 0.25-1x10^11 Msun span the full range of environments (i.e., field-to-group) exhibited by galaxies of the same mass and rest-frame color or specific star formation rate. Host galaxies having M_*>10^11 Msun clearly illustrate the association with star formation since they are predominantly bluer than the underlying galaxy population and exhibit a preference for lower density regions analogous to SDSS studies of narrow-line AGN. To probe the environment on smaller physical scales, we determine the fraction of galaxies (M_*>2.5x10^10 Msun) hosting AGNs inside optically-selected groups, and find no significant difference with field galaxies. We interpret our results as evidence that AGN activity requires a sufficient fuel supply; the probability of a massive galaxy to have retained some sufficient amount of gas, as evidence by its ongoing star formation, is higher in underdense regions where disruptive processes (i.e., galaxy harrassment, tidal stripping) are lessened., 13 pages; 11 figures; To appear in The Astrophysical Journal

Published
2009
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5. The Cosmic Evolution Survey (COSMOS) -- Overview

Author

Nick Scoville, D. Schminovich, Chris Impey, C. M. Carollo, Alvio Renzini, Marcella Brusa, Patrick L. Shopbell, Mauro Giavalisco, Jean-Paul Kneib, Neil De Grasse Tyson, David B. Sanders, Herve Aussel, Guenther Hasinger, R. M. Rich, Martin Elvis, O. LeFevre, Simon J. Lilly, Bahram Mobasher, Yoshiaki Taniguchi, Eva Schinnerer, Peter Capak, Luigi Guzzo, Scoville N., Aussel H., Brusa M., Capak P., Carollo C. M., Elvis M., Giavalisco M., Guzzo L., Hasinger G., Impey C., Kneib J.-P., LeFevre O., Lilly S.J., Mobasher B., Renzini A., Rich R.M., Sanders D.B., Schinnerer E., Schminovich D., Shopbell P., Taniguchi Y., and Tyson N.D.

Subjects
GALAXIES: EVOLUTION, Physics, Active galactic nucleus, 010308 nuclear & particles physics, Star formation, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Dark matter, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Cosmic variance, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, GALAXIES: SURVEYS, Galaxy, Redshift, Physical cosmology, Space and Planetary Science, 0103 physical sciences, Cosmos (category theory), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The Cosmic Evolution Survey (COSMOS) is designed to probe the correlated evolution of galaxies, star formation, active galactic nuclei (AGN) and dark matter (DM) with large-scale structure (LSS) over the redshift range z $> 0.5 $ to 6. The survey includes multi-wavelength imaging and spectroscopy from X-ray to radio wavelengths covering a 2 $\sq$��area, including HST imaging. Given the very high sensitivity and resolution of these datasets, COSMOS also provides unprecedented samples of objects at high redshift with greatly reduced cosmic variance, compared to earlier surveys. Here we provide a brief overview of the survey strategy, the characteristics of the major COSMOS datasets, and summarize the science goals., 22 pages, 3 figures

Published
2006

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