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1. Two-dimensional electron gas with universal subbands at the surface of SrTi[O.sub.3]

Author

Santander-Syro, A.F., Copie, O., Kondo, T., Fortuna, F., Pailhes, S., Weht, R., Qiu, X.G., Bertran, F., Nicolaou, A., Taleb-Ibrahimi, A., Le Fevre, P., Herranz, G., Bibes, M., Reyren, N., Apertet, Y., Lecoeur, P., Barthelemy, A., and Rozenberg, M.J.

Subjects
Electron configuration -- Research -- Chemical properties, Electron spectroscopy -- Research -- Chemical properties, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

As silicon is the basis of conventional electronics, so strontium titanate (SrTi[O.sub.3]) is the foundation of the emerging field of oxide electronics (1,2). SrTi[O.sub.3] is the preferred template for the creation of exotic, two-dimensional (2D) phases of electron matter at oxide interfaces (3-5) that have metal-insulator transitions (6,7), superconductivity (8,9) or large negative magnetoresistance (10). However, the physical nature of the electronic structure underlying these 2D electron gases (2DEGs), which is crucial to understanding their remarkable properties (11,12), remains elusive. Here we show, using angle-resolved photoemission spectroscopy, that there is a highly metallic universal 2DEG at the vacuum-cleaved surface of SrTi[O.sub.3] (including the non-doped insulating material) independently of bulk carrier densities over more than seven decades. This 2DEG is confined within a region of about five unit cells and has a sheet carrier density of ~0.33 electrons per square lattice parameter. The electronic structure consists of multiple subbands of heavy and light electrons. The similarity of this 2DEG to those reported in SrTi[O.sub.3]-based heterostructures (6,8,13) and field-effect transistors (9,14) suggests that different forms of electron confinement at the surface of SrTi[O.sub.3] lead to essentially the same 2DEG. Our discovery provides a model system for the study of the electronic structure of 2DEGs in SrTi[O.sub.3]-based devices and a novel means of generating 2DEGs at the surfaces of transition-metal oxides., In the cubic phase, stoichiometric SrTi[O.sub.3] has an empty [t.sub.2g] conduction manifold composed of three dispersive, three-dimensional (3D) bands that are degenerate at the C point (15). As schematically shown [...]

Published
2011
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2. A test of the nature of cosmic acceleration using galaxy redshift distortions

Author

Guzzo, L., Pierleoni, M., Meneux, B., Branchini, E., Le Fevre, O., Marinoni, C., Garilli, B., Blaizot, J., De Lucia, G., Pollo, A., McCracken, H. J., Bottini, D., Le Brun, V., Maccagni, D., Picat, J. P., Scaramella, R., Scodeggio, M., Tresse, L., Vettolani, G., Zanichelli, A., Adami, C., Arnouts, S., Bardelli, S., Bolzonella, M., Bongiorno, A., Cappi, A., Charlot, S., Ciliegi, P., Contini, T., Cucciati, O., de la Torre, S., Dolag, K., Foucaud, S., Franzetti, P., Gavignaud, I., Ilbert, O., Iovino, A., Lamareille, F., Marano, B., Mazure, A., Memeo, P., Merighi, R., Moscardini, L., Paltani, S., Pello, R., Perez-Montero, E., Pozzetti, L., Radovich, M., Vergani, D., Zamorani, G., and Zucca, E.

Subjects
Red shift -- Research -- Observations, Expanding universe -- Observations -- Research, Environmental issues, Science and technology, Zoology and wildlife conservation, Observations, Research
Abstract

Author(s): L. Guzzo (corresponding author) [1, 2, 3, 4]; M. Pierleoni [3]; B. Meneux [5]; E. Branchini [6]; O. Le Fèvre [7]; C. Marinoni [8]; B. Garilli [5]; J. Blaizot [...]

Published
2008
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5. A large population of galaxies 9 to 12 billion years back in the history of the Universe

Author

Le Fevre, O., Paltani, S., Arnouts, S., Charlot, S., Foucaud, S., Ilbert, O., McCracken, H. J., Zamorani, G., Bottini, D., Garilli, B., Le Brun, V., Maccagni, D., Picat, J. P., Scaramella, R., Scodeggio, M., Tresse, L., Vettolani, G., Zanichelli, A., Adami, C., Bardelli, S., Bolzonella, M., Cappi, A., Ciliegi, P., Contini, T., Franzetti, P., Gavignaud, I., Guzzo, L., Iovino, A., Marano, B., Marinoni, C., Mazure, A., Meneux, B., Merighi, R., Pello, R., Pollo, A., Pozzetti, L., Radovich, M., Zucca, E., Arnaboldi, M., Bondi, M., Bongiorno, A., Busarello, G., Gregorini, L., Lamareille, F., Mathez, G., Mellier, Y., Merluzzi, P., Ripepi, V., and Rizzo, D.

Subjects
Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Author(s): O. Le Fèvre (corresponding author) [1]; S. Paltani [1]; S. Arnouts [1]; S. Charlot [2, 3]; S. Foucaud [4]; O. Ilbert [1, 5]; H. J. McCracken [3, 12]; G. [...]

Published
2005
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6. A young source of optical emission from distant radio galaxies

Author

Hammer, F., Le Fevre, O., and Angonin, M.C.

Subjects
Radio astronomy -- Research, Quasars -- Research, Stars -- Luminosity function, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

The unified model states that powerful radio galaxies (PRG) and radio-loud quasars (QSR) are the same objects seen at decreasing angles between the radio axis and the line of sight.However, analysis of (O III) 5,007-angstrom luminosities of QSR showed them to be 5-10 times higher than those of similar PRG. To check the validity of the unified model, similar analyses were conducted using (O II) 3,727-angstrom emission line luminosities. The results were in accordance with the predictionsof the unified model.

Published
1993

7. A test of the nature of cosmic acceleration using galaxy redshift distortions

Author

Sylvie Foucaud, F. Lamareille, E. Zucca, Alain Mazure, A. Pollo, M. Pierleoni, V. Le Brun, L. Tresse, O. Ilbert, S. Bardelli, O. Cucciati, S. de la Torre, Marco Scodeggio, C. Adami, M. Bolzonella, G. De Lucia, G. Zamorani, J. P. Picat, D. Bottini, Klaus Dolag, P. Memeo, A. Iovino, Enrique Perez-Montero, Gianpaolo Vettolani, Roberto Scaramella, B. Meneux, H. J. McCracken, R. Merighi, Thierry Contini, Lauro Moscardini, J. Blaizot, B. Garilli, I. Gavignaud, Bruno Marano, D. Maccagni, Stéphane Paltani, Stephane Charlot, A. Zanichelli, Luigi Guzzo, R. Pello, Enzo Branchini, A. Cappi, Angela Bongiorno, Mario Radovich, Christian Marinoni, D. Vergani, Stephane Arnouts, Lucia Pozzetti, Paolo Ciliegi, P. Franzetti, O. Le Fevre, Istituto di Astrofisica Spaziale e Fisica cosmica - Bologna (IASF-Bo), Istituto Nazionale di Astrofisica (INAF), AUTRES, 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 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), Centre de Physique Théorique - UMR 7332 (CPT), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Istituto di Astrofisica Spaziale e Fisica Cosmica - Milano (IASF-MI), INAF - Osservatorio Astronomico di Brera (OAB), INAF - Osservatorio Astronomico di Bologna (OABO), INAF - Osservatorio Astronomico di Capodimonte (OAC), Service de Physique Théorique (SPhT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), 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), University of Oxford, Services communs OMP (UMS 831), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées (LATT), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), INAF - Osservatorio Astronomico di Roma (OAR), Istituto di Radioastronomia [Bologna] (IRA), Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Max-Planck-Institut für Astrophysik (MPA), Max-Planck-Gesellschaft, Dipartimento di Fisica, Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB)-Università degli Studi di Milano = University of Milan (UNIMI), European Southern Observatory (ESO), INAF - Osservatorio Astronomico di Bologna (OAB), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Observatoire de Paris - Site de Paris (OP), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institute of Liver Studies, King's College Hospital (KCH), Guzzo, L., Pierleoni, M., Meneux, B., Branchini, E, Le Fèvre, O., Marinoni, C., Garilli, B., Blaizot, J., De Lucia, G., Pollo, A., Mccracken, H. J., Bottini, D., Le Brun, V., Maccagni, D., Picat, J. P., Scaramella, R., Scodeggio, M., Tresse, L., Vettolani, G., Zanichelli, A., Adami, C., Arnouts, S., Bardelli, S., Bolzonella, M., Bongiorno, A., Cappi, A., Charlot, S., Ciliegi, P., Contini, T., Cucciati, O., de la Torre, S., Dolag, K., Foucaud, S., Franzetti, P., Gavignaud, I., Ilbert, O., Iovino, A., Lamareille, F., Marano, B., Mazure, A., Memeo, P., Merighi, R., Moscardini, L., Paltani, S., Pellò, R., Perez-Montero, E., Pozzetti, L., Radovich, M., Vergani, D., Zamorani, G., Zucca, E., 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 de Toulon (UTLN)-Université de Provence - Aix-Marseille 1-Université de la Méditerranée - Aix-Marseille 2, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), University of Oxford [Oxford], 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), 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, Università di Bologna, Dipartimento di Astronomia, Università degli Studi di Milano-Bicocca [Milano] (UNIMIB)-Università degli Studi di Milano [Milano] (UNIMI), Guzzo L., Pierleoni M., Meneux B., Branchini E., Le Fevre O., Marinoni C., Garilli B., Blaizot J., De Lucia G., Pollo A., McCracken H.J., Bottini D., Le Brun V., Maccagni D., Picat J.-P., Scaramella R., Scodeggio M., Tresse L., Vettolani G., Zanichelli A., Adami C., Arnouts S., Bardelli S., Bolzonella M., Bongiorno A., Cappi A., Charlot S., Ciliegi P., Contini T., Cucciati O., de La Torre S., Dolag K., Foucaud S., Franzetti P., Gavignaud I., Ilbert O., Iovino A., Lamareille F., Marano B., Mazure A., Memeo P., Merighi R., Moscardini L., Paltani S., Pello' R., Perez-Montero E., Pozzetti L., Radovich M., Vergani D., Zamorani G., and Zucca E.

Subjects
High Energy Physics - Theory, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Astrophysics::Cosmology and Extragalactic Astrophysics, Cosmological constant, Astrophysics, 01 natural sciences, General Relativity and Quantum Cosmology, Cosmology, Metric expansion of space, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Redshift-space distortions, galaxies, 0103 physical sciences, 010303 astronomy & astrophysics, Physics, Multidisciplinary, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, Astrophysics (astro-ph), Redshift survey, Redshift, Galaxy, High Energy Physics - Theory (hep-th), [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Dark energy
Abstract

Observations of distant supernovae indicate that the Universe is now in a phase of accelerated expansion the physical cause of which is a mystery. Formally, this requires the inclusion of a term acting as a negative pressure in the equations of cosmic expansion, accounting for about 75 per cent of the total energy density in the Universe. The simplest option for this "dark energy" corresponds to a cosmological constant, perhaps related to the quantum vacuum energy. Physically viable alternatives invoke either the presence of a scalar field with an evolving equation of state, or extensions of general relativity involving higher-order curvature terms or extra dimensions. Although they produce similar expansion rates, different models predict measurable differences in the growth rate of large-scale structure with cosmic time. A fingerprint of this growth is provided by coherent galaxy motions, which introduce a radial anisotropy in the clustering pattern reconstructed by galaxy redshift surveys. Here we report a measurement of this effect at a redshift of 0.8. Using a new survey of more than 10,000 faint galaxies, we measure the anisotropy parameter b = 0.70 +/- 0.26, which corresponds to a growth rate of structure at that time of f = 0.91 +/- 0.36. This is consistent with the standard cosmological-constant model with low matter density and flat geometry, although the error bars are still too large to distinguish among alternative origins for the accelerated expansion. This could be achieved with a further factor-of-ten increase in the sampled volume at similar redshift., One PDF file including both main paper and Supplementary Information (28 pages, 3+2 figures). Published version available at http://www.nature.com/nature/journal/v451/n7178/abs/nature06555.html

Published
2007

8. Impact of localized badger culling on tuberculosis incidence in British cattle

Author

Andrea M. Le Fevre, Rosie Woodroffe, W. Ivan Morrison, John Bourne, J.P. McInerney, Christl A. Donnelly, George Gettinby, and David Cox

Subjects
Tuberculosis, Meles mele, Time Factors, Badger, animal diseases, Carnivora, Population Dynamics, Wildlife, Culling, Meles, biology.animal, medicine, Animals, bovine tuberculosis, Socioeconomics, Wildlife conservation, Mycobacterium bovis, Multidisciplinary, biology, Ecology, business.industry, Incidence, biology.organism_classification, medicine.disease, United Kingdom, British cattle, tuberculosis, Livestock, Cattle, Pathogens, business, badger culling, Tuberculosis, Bovine
Abstract

Pathogens that are transmitted between wildlife, livestock and humans present major challenges for the protection of human and animal health, the economic sustainability of agriculture, and the conservation of wildlife. Mycobacterium bovis, the aetiological agent of bovine tuberculosis (TB), is one such pathogen. The incidence of TB in cattle has increased substantially in parts of Great Britain in the past two decades, adversely affecting the livelihoods of cattle farmers and potentially increasing the risks of human exposure. The control of bovine TB in Great Britain is complicated by the involvement of wildlife, particularly badgers (Meles meles), which appear to sustain endemic infection and can transmit TB to cattle. Between 1975 and 1997 over 20,000 badgers were culled as part of British TB control policy, generating conflict between conservation and farming interest groups2. Here we present results from a large-scale field trial3–5 that indicate that localized badger culling not only fails to control but also seems to increase TB incidence in cattle.

Published
2003

9. A young source of optical emission from distant radio galaxies

Author

Francois Hammer, O. Le Fevre, and M. C. Angonin

Subjects
Luminous infrared galaxy, Physics, Multidisciplinary, Radio galaxy, business.industry, Astrophysics, Spectral line, Redshift, Galaxy, Stars, Optics, X-shaped radio galaxy, Light emission, business
Abstract

DISTANT radio galaxies provide valuable insights into the properties of the young Universe-they are the only known extended optical sources at high redshift and might represent an early stage in the formation and evolution of galaxies in general. This extended optical emission often has very complex morphologies, but the origin of the light is still unclear. Here we report spectroscopic observations for several distant radio galaxies (0.75≤ z ≤ 1.1) in which the rest-frame spectra exhibit featureless continua between 2,500 A and 5,000 A. We see no evidence for the break in the spectrum at 4,000 A expected for an old stellar population1-3, and suggest that young stars or scattered emissions from the active nuclei are responsible for most of the observed light. In either case, this implies that the source of the optical emission is com-parable in age to the associated radio source, namely 107 years or less.

Published
1992

10. Positive and negative effects of widespread badger culling on tuberculosis in cattle

Author

Donnelly, Christl A., primary, Woodroffe, Rosie, additional, Cox, D. R., additional, Bourne, F. John, additional, Cheeseman, C. L., additional, Clifton-Hadley, Richard S., additional, Wei, Gao, additional, Gettinby, George, additional, Gilks, Peter, additional, Jenkins, Helen, additional, Johnston, W. Thomas, additional, Le Fevre, Andrea M., additional, McInerney, John P., additional, and Morrison, W. Ivan, additional

Published
2005
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11. Is 3C324 the first gravitationally lensed giant galaxy?

Author

O. Le Fevre, Francois Hammer, G. Mathez, and L. Nottale

Subjects
Physics, Multidisciplinary, Radio galaxy, Astronomy, Gravitational mirage, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy, Astronomical spectroscopy, Redshift, Luminosity, Gravitational lens, Emission spectrum, Astrophysics::Galaxy Astrophysics
Abstract

The radiogalaxy 3C324 has recently raised considerable interest as one of the most distant (redshift z = 1.206) and luminous known galaxies. Here we report new observations of this object at Canada–France–Hawaii Telescope which confirm our previous predictions of the presence of an intervening gravitational lens. First, a multiple structure is revealed by our charge-coupled device (CCD) broadband imagery. Second, following our previous identification in the 3C324 spectrum of an additional line system at z=0.84, subsequent CCD observation through interferential filters were planned. In a wavelength range corresponding to an emission line at z=0.84 only the central component is detected, while only outer components are seen in a range corresponding to a line redshifted by z=1.206. These observations are interpreted as the first example of gravitational multiple imaging of a giant radiogalaxy by a foregound object. So galaxy 3C324 seems to be a gravitational mirage—though further spectroscopic observations will be needed to establish whether the two images have similar spectra.

Published
1987
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13. The Temperature Scale

Author

E.J. Le Fevre

Subjects
Multidisciplinary, Scale of temperature, medicine, Mechanics, medicine.symptom, Mathematics, Confusion, Unit (housing)
Abstract

THE proposal made by Prof. J. C. Georgian1 is in my view unsatisfactory in so far as it involves not only a change of unit but a change in the definition of the quantity, temperature. Temperature is a macrophysical quantity and confusion arises if it be given a pseudomicroscopic redefinition.

Published
1964
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