archive-fr.com » FR » U » UNIVEARTHS.FR

Total: 629

Choose link from "Titles, links and description words view":

Or switch to "Titles and links view".
  • E6: Gamma-Ray Bursts as Multi-messengers | UnivEarthS
    but a direct proof of this model is still lacking The high energy part of the GRB spectrum The observation by the Fermi LAT of several GRB photons with energies reaching 50 100 GeV in the source frame is an encouraging sign for GRB detections with the next generation of instruments operating in the GeV and TeV domain The extrapolation of Fermi LAT spectral measurements to the VHE domain is difficult due to the limited knowledge of GRB properties at these energies see Gehrels Razzaque Frontiers of Physics 2013 In particular it remains unclear whether the hard component observed in the spectra of several bright Fermi GRBs is a common property at GeV energies In addition intrinsic spectral cut offs similar to the case of GRB 090926A are expected at 1 100 GeV energies and are strongly related to the value of the GRB jet Lorentz factor For these reasons current estimates of the GRB detection rate by future TeV experiments like CTA suffer from important uncertainties and range from 0 5 to 2 GRBs per year Inoue et al Astropart Phys 43 252 2013 Nonetheless during the lifetime of SVOM a few but invaluable GRB detections are thus expected in the 0 05 0 5 TeV range from CTA especially in the light of the recent bright GeV afterglow detected for GRB 130427A Tam et al ApJ 77 L13 2013 Joint time resolved spectral analyses based on SVOM and CTA data will also help to pinpoint the acceleration and emission processes occurring in GRB jets Studies of the GRB prompt emission phase from sub MeV to sub TeV energies can help to distinguish between leptonic and hadronic models and to investigate the possibility of GRBs being a source of ultra high energy cosmic rays and answer the long standing question of the origin of the cosmic rays observed on Earth with energies larger than 10 10 GeV GRBs and the new messengers To date neutrino and gravitational wave signals detected by current experiments could not be correlated with any precise astrophysical source Thanks to their short duration and their high flux GRBs are the best electromagnetic counterpart candidates and a simultaneous detection would represent the start of a new era for those two research fields namely the astronomy era Neutrinos Neutrinos are unique messengers to study the high energy Universe as they are neutral and stable interact weakly and therefore travel directly from their point of creation to the Earth without absorption Neutrinos could play an important role in understanding the mechanisms of cosmic ray acceleration and their detection from a cosmic source would be a direct evidence of the presence of hadronic acceleration Indeed HE neutrinos are produced in a beam dump scenario via meson mainly pion π decay when the accelerated hadrons protons or nuclei interact with ambient matter or dense photon fields The emitted neutrinos typically have an energy which is about 10 of the energy of the interacting protons The production of neutrinos of 10

    Original URL path: http://www.univearths.fr/en/e6-gamma-ray-bursts-multi-messengers (2015-10-10)
    Open archived version from archive


  • E7: Advanced time series analysis: application to Microscope data | UnivEarthS
    29 30 31 Sign in Password forgotten Home PROJECTS Exploratory Projects Advanced time series analysis E7 Advanced time series analysis application to Microscope data Cosmology and fundamental physics Presentation Team Results experimence News Advanced time series analysis application to Microscope data Context The Weak Equivalence Principle WEP states the equality between the inertial mass and the gravitational mass universality of free fall and is a cornerstone of General Relativity GR It can be tested with the Eötvös parameter which is zero if the WEP exactly holds proportional to the difference of the accelerations felt by two bodies made of different materials in the same gravity field Physics beyond GR e g string theory inspired gravity theories may explain the accelerated expansion of the Universe and solve the dark energy problem In this case we predict a WEP violation between 10 18 and 10 13 while the current experimental limits are 10 13 The existing experiments on Earth are reaching their limits so it is important to test the WEP in space MICROSCOPE a French Space Agency mission expected to launch in 2016 will improve the current limits by 2 orders of magnitude Microscope MICROSCOPE French for Drag free micro satellite for the Observation of the Equivalence Principle is made of two ultrasensitive cylindrical electrostatic differential accelerometers The first one consists of two coaxial test masses made of the same material Pt and is used to check for systematics the second one consists of two coaxial test masses made of different material Pt and Ti and will effectively test the WEP A violation of the Equivalence Principle is measured as the difference in acceleration experienced by the proof masses as they orbit the Earth Measurement principle the WEP is tested along a given axis A WEP violation results in a signal

    Original URL path: http://www.univearths.fr/en/e7-advanced-time-series-analysis-application-microscope-data (2015-10-10)
    Open archived version from archive

  • Former Exploratory projects | UnivEarthS
    Universe Support au PCCP The transient catastrophic Universe Interface projects Geoparticles Fundamental physics and Geophysics in space From dust to planets Former Interface projects Formation and early evolution of Planetary systems The youth of cosmic rays and their emergence in the interstellar clouds Gamma ray instrumentation development Young team project Experimental geophysics Valorization project Data distribution visualisation and cloud computing PUBLICATIONS EDUCATIONAL Nanosatellite student project IGOsat UnivEarthS JOB OPPORTUNITY Experimental

    Original URL path: http://www.univearths.fr/en/former-exploratory-projects (2015-10-10)
    Open archived version from archive

  • E1 : Formation of dunes and climate on Titan | UnivEarthS
    on Earth Mars ie sublimation and Titan ie cohesion Planetary sciences By combining the skills regarding the analysis of observations of planetary surfaces and atmospheres AIM laboratory with skills developed within IPGP regarding numerical modelling of complex geophysical systems the project aims to analyze the dynamics of sedimentary bedforms on Titan Leader and co leader of the work package Sébastien Rodriguez Associate Professor AIM University Paris Diderot phone 33 0 1 69 08 80 56 email sebastien rodriguez cea fr web Clément Narteau Associate Professor HDR IPGP University Paris Diderot phone 33 0 1 83 95 74 23 email narteau ipgp fr web www ipgp fr narteau Non permanent members of the team and collaborators Amandine Garcia PhD student AIM phone 33 0 1 69 08 80 56 email amandine garcia cea fr Antoine Lucas Postdoc CNES AIM phone email antoine lucas cea fr Xin Gao PhD student IPGP phone 33 0 1 83 95 77 76 email gao ipgp fr Lü Ping Postdoc IPGP phone 33 0 1 83 95 74 02 email lvping ipgp fr Sylvain Courrech du Pont Associate Professor MSC Lab University Paris Diderot phone 33 0 1 57 27 62 84 email sylvain courrech univ paris diderot fr web 1 Deserts Growth and stability of star dunes under the effect of multidirectional flows Towards a better understanding of the orientation modes of dune crests Star dunes are giant dunes whose ramifications extend in many directions From numerical models taking into account the multidirectional wind regimes researchers from the Institut de Physique du Globe de Paris IPGP CNRS and the Laboratory of Matter and Complex Systems CNRS MSC have shown that star dunes could be considered as a superposition of longitudinal dunes The direction and the rate of growth of each branch can then be predicted as a function of the configuration of the flow and the quantity of sand available These new results open new perspectives for the analysis of dune fields and sediment transport in many geophysical environments subjected to multidirectional flows Star dunes can be described as a tangle of dune forms whose crests and sides of avalanche spread in multiple directions They usually consist of a central dome which grows on smaller structures with apparently no preferred orientation Probably because these star dunes are very large more than 100 m high and apparently highly complex their shapes and dynamics have been until now very few studied The majority of these studies rely on secondary flows which depending on the topography create recirculation currents in directions oblique to the main flow These flows are the cause of the growth of arms and would control the final shape of the dunes The new findings go against this hypothesis and clearly show that star dunes can be produced from the sediment transport associated with each of the main directions of flow This work also shows that the ramifications of star dunes have morphological characteristics height width and growth velocity depending on the wind conditions For

    Original URL path: http://www.univearths.fr/en/e1-formation-dunes-and-climate-titan (2015-10-10)
    Open archived version from archive

  • E2 : Impact of black holes on their environment | UnivEarthS
    Mass Black Holes in the re ionization era FM PL International Collaborations Dr Mark Dijkstra MPA Garching Germany Prof Lev Titarchuk Univ of Ferrara Italy Dr Leonardo Pellizza IAFE Buenos Aires Argentina Visiting Scientist Programs Mark Dijkstra MPA Garching Germany visiting scientist at AIM APC in April 2013 Lev Titarchuk Univ of Ferrara Italy visiting scientist at APC AIM in April 2013 Vanesa Douna IAFE Buenos Aires Argentina visiting PhD student at AIM APC 2 16 Sep 2013 F Mirabel visit of IAFE Buenos Aires Argentina 1 month April May 2014 B SuperMassive Black Holes in AGN VB SS SDJ Formation activities Master trainings PhDs Thesis and Post doctoral positions March June 2011 Master 2 research traineeship on AGN emission processes of NGC 4945 in the X rays and gamma rays by M L Menzel supervisor VB May July 2012 Master 1 research traineeships on X ray emission from the radio galaxies M87 and Cen A by Dounia Saez and Pierre Li Cavoli supervisor VB since Oct 2010 PhD thesis of S de Jong on Accretion Processes in Active Galactic Nuclei at high energies supervisor VB Accepted Observation Proposals and Programs INTEGRAL and SWIFT simultaneous observations of NGC 7172 performed in 2011 PI SS INTEGRAL and SWIFT simultaneous observations of NGC 5506 performed in 2012 PI SS SWIFT and INTEGRAL follow up of non blazar Fermi AGN performed in 2012 PI SDJ INTEGRAL observations of M87 performed in 2011 and 2012 PI VB INTEGRAL and XMM Newton simultaneous observations of NGC 2992 approved in 2011 PI VB and then performed in 2013 INTEGRAL proposal to observe NGC 2110 submitted PI VB and approved in 2013 Workshops Conferences Collaboration Programs The X ray Universe 2011 conference in Berlin June 2011 contributed talks VB SS and poster SDJ The Physics of Astronomical Transients conference in Aspen USA January 2012 contributed talks SS VB Fermi summer school in Lewes USA May 2012 contributed talk SDJ COSPAR 2012 Mysore India July 2012 VB as main scientific organizer of escientific event invited talk and 2 posters by VB 9th INTEGRAL Workshop Paris October 2012 contributed talk by SS and VB posters by SS VB SDJ Organisation of a session on Outflows and Accretion from White Dwarfs to Supermassive Black Holes VB deputy scientific organiser at the next COSPAR Assembly 2014 in Moscow Spring school on Cosmic Accelerators Cargèse France 29 April 8 May 2013 with contributed talk SdJ and lecture VB Conference The restless nature of AGNs variability as a probe of the central engine Naples Italy 20 23 May 2013 contributed talk by SS Participation to the INTEGRAL Workshop Rome 15 18 10 2013 invited talk by VB International Collaborations C Shrader NASA GSFC Greenbelt US P Lubinski Torun Poland N Gehrels NASA GSFC Greenbelt US C Ricci ISDC Geneva Switzerland and then Kyoto Univ Japan A Tramacere ISDC Geneve CH J Tueller NASA GSFC Greenbelt US J Kennea Penn State University Philadelphia US Visiting Scientist Programs Chris Shrader visiting scientist at APC in October 2011 C The Galactic Center SuperMassive Black Hole AG RT MC SS GT Formation activities Master training PhD Thesis and Post doctoral positions 2011 Master 1 reasearch traineeship on Limits on the past activity of the GC SMBH on the basis of the INTEGRAL data by A Pottier supervisor RT March June 2011 Master 2 research traineeship Doctoral School A A on Search for past activities of close SMBH in external galaxies by M Clavel supervisor RT Sep 2011 Thesis defense Doctoral School NPAC of G Trap on Galactic Center High Energy emission supervisor AG since Oct 2011 PhD thesis on the Galactic Center Black Hole of M Clavel supervisors AG and RT since Dec 2012 CNES fellowship 2 yrs for S Soldi to work at APC on the data of the 2012 XMM Large Project survey of the Galactic Center Observation Proposals and Programs Chandra Obs of Molecular Clouds around Sgr A complex performed in July 2011 PI RT XMM VLT Observations of Sgr A in March 2012 PI AG participation to a new large multi wavelength campaign on Sgr A visiting observer at Paranal MC A Large Project 700 ks proposal for obs with XMM of the GC region for the XMM AO11 call submitted in Oct 2011 PI RT and approved LP XMM Observations of the GC region PI RT performed in October 2012 Two Proposals 1 survey 1 ToO for XMM Obs in 2013 of the cloud G2 approaching Sgr A submitted for AO12 in Oct 2012 and approved PI Ponti Proposal for a 100 ks observation of Sgr C with Chandra PI SS submitted in March 2013 and approved for Chandra cycle 15 Proposal for sub mm Carma observations of Sgr A molecular complex submitted May 2013 PI MC approved October 2013 Proposal for XMM observations of Sgr B2 complex submitted in October 2013 PI RT Workshops Conferences Collaboration Programs Proposal for an ISSI international team submitted in 2011 PI AG and approved GC ISM Heidelberg Meeting October 2011 2 invited talks AG RT 1 poster MC Ginzburg Conference on theoretical physics Moscow May 2012 invited talk on Activity of the GC SMBH by AG First ISSI IT meeting on the Galactic Center held in May 2012 see the IT ISSI Web pages at http www issibern ch teams galacticbh 2012 SF2A meeting Nice June 2012 contr talk by MC financed Ecole Doctorale PNHE COSPAR 2012 Mysore India July 2012 scientific event invited talk by AG 9 th INTEGRAL Workshop Paris October 2012 solicited talk by RT contributed talk by MC Organization of a session on the Galactic Center Supermassive Black Hole at the next COSPAR Assembly 2014 in Moscow AG main scientific organiser Proposal to the Ulysses call for reasearch visits program with Ireland for a collaboration with M Chernyakova s group in Dublin to develop together a simulation code of reflection processes in the GC region submitted in Sep 2012 PI AG M Chernyakova approved Lorentz Center Workshop A New View of

    Original URL path: http://www.univearths.fr/en/e2-impact-black-holes-their-environment (2015-10-10)
    Open archived version from archive

  • Frontier projects | UnivEarthS
    living planet From the Big Bang to the future Universe Support au PCCP The transient catastrophic Universe Interface projects Geoparticles Fundamental physics and Geophysics in space From dust to planets Former Interface projects Formation and early evolution of Planetary systems The youth of cosmic rays and their emergence in the interstellar clouds Gamma ray instrumentation development Young team project Experimental geophysics Valorization project Data distribution visualisation and cloud computing PUBLICATIONS

    Original URL path: http://www.univearths.fr/en/frontier-projects (2015-10-10)
    Open archived version from archive

  • F1 : Earth as a living planet: from early ages to present dynamics | UnivEarthS
    of aquatic anoxic and ferruginous system as Pavin lake Massif Central as a modern proxy of Archean ocean Isotopic signatures of biogeochemical process from the water column to the sediment IPGP Bureau 515 33 1 83 95 74 34 busigny ipgp fr Pierre Cartigny S 36 S 32 S 33 S 32 S 34 S 32 S and O 17 O 16 O 18 O 16 O isotopic compositions analysis to reconstruct the paleo environmental conditions and atmospheric composition of the Archean and Neoproterozoique IPGP Bureau 511 33 1 83 95 75 11 cartigny ipgp fr Frédéric Fluteau Pre Quaternary climatic changes studies with numerical modelling of climate C biogeochemical cyce and continental weathering Quantification of processes controlling Earth climate Reconstitution of physical and chemical evolution of fluid reservoir of the Archean with 3D climate and geochemistry modelling IPGP Bureau 128 33 1 83 95 74 92 fluteau ipgp fr Jérôme Gaillardet Identification of isotopic mineralogical and geochemical signature of water and river sediments produced by interaction with sulfuric acid Interpretation of ancient sediment with important chemical weathering rate Possible isotopic proxy Mo W Cr exploration in Precambrian rocks IPGP Bureau 413 33 1 83 95 74 83 gaillard ipgp fr Robin Lacassin IPGP Bureau 216 33 1 83 95 76 24 lacassin ipgp fr Guillaume Le Hir Pre Quaternary climatic changes studies with numerical modelling of climate C biogeochemical cyce and continental weathering Quantification of processes controlling Earth climate Reconstitution of physical and chemical evolution of fluid reservoir of the Archean with 3D climate and geochemistry modelling IPGP Bureau 130 33 1 83 95 74 93 lehir ipgp fr Johanna Marin Carbonne Metal stable isotope analysis to better understand the possible biological and redox signatures in ancient sediment Petrographical and mineralogical study of drillcore and in situ analyses of stable isotope IPGP Bureau 167 33 1 83 95 73 89 mcarbonne ipgp fr Pascal Philippot Deep Biosphere and Origin of Life IPGP Bureau 141 33 1 83 95 73 87 philippot ipgp fr Natalia Poiata Analysis of seismicity in Chile aftershock sequence of the 2010 Maule earthquake and seismicity in North Chile after the 2007 Tocopilla earthquake Development of new array based methods for detection and localization of seismic events IPGP Bureau 324 33 1 83 95 75 85 poiata ipgp fr Nikolai Shapiro IPGP Bureau 328 33 1 83 95 75 78 nshapiro ipgp fr Mark Van Zuilen Structural chemical and isotopic characterization of possible biological structure present in ancient rocks microfossils in chemical sediments micro laminations in stromatolithes and minerals in hydrothermal environment Characterization of life signatures in archean rocks structure of metamorphosed carbone by Raman spectroscopy and FIB TEM In situ analysis of isotopic and elemental compositions of organic material and associated minerals δ 13 C N C ratio δ 34 S Δ 33 S IPGP Bureau 167 33 1 83 95 75 27 vanzuilen ipgp fr Jean Pierre Vilotte Mechanical and numerical modeling of earthquake rupture dynamics Numerical simulation of wave propagation in complex geological systems Coherent interferometry imaging of extended earthquake sources Computational physics and parallel computing IPGP Bureau 167 33 1 83 95 75 83 vilotte ipgp fr Ernesto Pecoits Sedimentolgy trace element geochemistry Development of new array based methods for detection and localization of seismic events IPGP Bureau Pecoits ipgp fr Wafa Abouchami Isotope Geochemistry IPGP Bureau awafa ipgp fr In addition to IPGP collaborators several colleagues from France USA Australia and Canada are involved in the TCDP Project These include Stefan Lalonde University of Brest Christophe Thomazo Emmanuelle Vennin and Jean François Buoncristiani Dijon University Kevin Lepot University of Lille Martin Van Kranendonk University of New South Wakes Kurt Konhauser University of Alberta Noah Planavsky Yale University DRILLING SITES The TCDP was performed during April and May 2013 Three drilling sites were chosen in three different stratigraphic intervals of the Turee Creek Group TCDP1 22 48 31 00 S 116 47 15 90 E intercepts the contact between the underlying banded iron formation of the Boolgeeda Formation Hamersley Group and the overlying Kungara formation of the Turee Creek Gp TCDP2 22 50 49 70 S 116 52 27 70 E intercepts the base of diamictites of the Meteorite Bore Member and part of the underlying mudstone siltstone and carbonate bearing stromatolite of the Kungara Formation TCDP3 22 52 15 90 S 116 56 46 40 E intercepts the base of the Kazput Formation and underlying Koolbye quartzites Total depth of drilling is 746 m with 292 m RC collar and 454 m NQ diamond drilling The drilling research team consisted of Pascal Philippot and Elodie Muller IPGP and Martin Van Kranendonk University of New South Wales Paul Van Loenhout of Mount Magnet and his crew are thanked for their professional work and enthusiasm in obtaining the drillcore Two new publications 7 July 2015 18 16 Several Members of the Frontier Project Earth as a living Planet published their work in the Proceedings of the National Academy of Science and Frontiers in Earth Science En savoir plus Wafa Abouchami joins the Frontier project F1 1 7 July 2015 18 14 After Johanna Marin Carbonne and Ernesto Pecoits Wafa Abouchami recently joined our group to work on the Frontier project F1 1 dedicated to the Redox Evolution of the Earth Wafa is a geochemist specialized in the analysis of Cd and Pb isotopes as tracers of past and present oceanic circulations and crustal growth processes She is joining IPGP to perform the Cd and Mo isotope systematics of the drill core samples obtained as part of the Turee Creek Drilling Project together with Vincent Busigny En savoir plus Publication link between tectonics and climate in the formation of the Andes 18 March 2015 12 32 En savoir plus Seminar Tracking oxidative weathering on the early Earth Evolutionary and ecological implications 24 November 2014 14 49 Ernesto PECOITS postdoct of Earth as a living planet From early ages to present dynamics project will present several seminars during his stay at IPGP The first one

    Original URL path: http://www.univearths.fr/en/f1-earth-living-planet-early-ages-present-dynamics (2015-10-10)
    Open archived version from archive

  • F2 : From the Big Bang to the future Universe | UnivEarthS
    sensitive experiment with an exquisite control of systematic errors Most of the experiments or projects dedicated to the quest are based on the well known direct imaging technology While imagers measure maps of the CMB interferometers directly measure Fourier components of the Stokes parameters and thus are expected to be less sensitive to systematic effects Unfortunately the classical heterodyne interferometry concept may have reached its limits in term of scale and sensitivity However Bolometric Interferometry could combine the advantages of interferometry in terms of systematic effects handling and those of direct detectors in terms of sensitivity Although many experiments are already proposed in the USA ground based and balloon borned only one project is emerging in Europe the QUBIC program supported by a French Italian USA UK Irish collaboration http www qubic org The APC CMB team including its experimental laboratory is leading this research effort with particular interest in Conception and design of the QUBIC instrument Data analysis and simulations Development of the detection chain Bolometer arrays based on the Transition Edge Sensors TES technology and multiplexed readout Kinetic Inductance Detectors KIDs a new path towards large detector arrays this new detection technique uses the variation of kinetic inductance of a superconductor when it absorbs a photon flux Their advantages are the following i they are relatively simple to fabricate ii the readout electronics is inherently multiplexed allowing for a large number of detectors of the order of 1000 or more to be readout with a single wire and iii the intrinsic sensitivity could theoretically be very high We propose to couple these new detectors with the current developments made for TESs Within 2 years a demonstrator of some 100s KIDs will be realized fully compatible with the QUBIC requirements The number of detectors will be further improved to reach some thousands of KIDs within 10 years Realization of receiver horns based on the platelets technology The goal is to achieve during the 4 coming years a complete design of the final instrument which means that it will be necessary to develop all the detector chain and choose between the 2 possible solutions we are working on KIDS and TES based arrays We will also have to build a prototype of the first module within 2 years in order to perform first observations on the sky and consequently to tune and improve the behaviour of this first module As developed in section 6 we intent to put the LABEX contributions on the KIDs development and on the conception and design of the instrument which is now well established but still needs some important effort in the data analysis aspects The description of the concept is on the process to be published and available on the archive QUBIC The QU Bolometric Interferometer for Cosmology E Battistelli et al astro ph 1010 0645 and submitted to AstroParticle Physics 3 Understanding the nature of Dark Energy The other sub work package has a different timeline it concerns the analysis of data of

    Original URL path: http://www.univearths.fr/en/f2-big-bang-future-universe (2015-10-10)
    Open archived version from archive