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  • 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?mini=node%2F333%2F2015-11 (2015-10-10)
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  • 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?quicktabs_menu_e1_en=0 (2015-10-10)
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  • News on dunes ! | UnivEarthS
    our EXODUNES ANR project is funded PI S Rodriguez C and S Narteau Courrech Bridge Beginning 1st January 2013 January June 2012 M2 internship of Amandine Garcia at AIM lab on the topic Mapping and experimental study of dune fields on Titan link with wind models Titan Saturn s satellite is the second largest satellite of the solar system and the only one to possess a dense atmosphere and an active climatology Its huge interest triggers the Cassini Huygens mission The VIMS into infrared wavelength and the RADAR instrument in SAR mode onboard the Cassini orbiter are able to observe Titan s surface My work is to study dunes a particular geomorphological unit strongly linked with the climate RADAR SAR global mapping reveals the presence of large areas of linear dunes all confined to Titan s equatorial regions 30 N 30 S Gathering the spectral heterogeneity of terrains given by VIMS and the location of the dunes imaged by the RADAR SAR we can give the total area covered by Titan s dune fields around the whole equatorial region 22 of the surface of Titan i e 18 000 000 km 2 They are an important memory of past and actual Titan s climate It is in particular possible to constrain the surface winds over the dunes by looking more locally how dunes react converge diverge around obstacle This behavior is directly linked to the wind regime and the obstacle s geometry To better understand this we decide to reproduce millimeter dunes in laboratory experiment applying winds surface predicted by the climate model in order to study their behavior around obstacle setting at Titan scale The order magnitude of the aspect ratio between the height of the dunes and the height of the obstacle of 1 6 that we infer from the RADAR SAR data analysis radarclinometry allows to put in scale for laboratory experiments The main result of these experiments shows an inconsistent with the SAR observations by the appearance in the experiments of two erosion zones while we expected a solely long erosion zone It puts into question the validity of the winds predicted by the climate model However it is still a work in progress and we need to gather more observations experiments and numerical simulations to better understand the morphogenesis of Titan s dunes and to better constrain Titan s climate In the course of 2012 2 month visit of professor Zhibao Dong at the University Paris Diderot Within CAREERI Cold and Arid Regions Environmental and Engineering Research Institute Professor Dong Zhibao is the executive director of the laboratory of Deserts and Desertification Zhibao Dong is specialist of aeolian transport and dune morphodynamics His work in the field and with wind tunnel make him a world expert on the geomorphology of arid areas The purpose of his visit was to combine observations to numerical modeling and experimental studies conducted in Diderot Paris IPGP MSC and AIM It will incorporate many projects BQR LIA ANR In particular

    Original URL path: http://www.univearths.fr/en/node/300 (2015-10-10)
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  • E2 : Impact of black holes on their environment | UnivEarthS
    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 Accretion

    Original URL path: http://www.univearths.fr/en/e2-impact-black-holes-their-environment?mini=node%2F333%2F2015-09 (2015-10-10)
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  • E2 : Impact of black holes on their environment | UnivEarthS
    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 Accretion

    Original URL path: http://www.univearths.fr/en/e2-impact-black-holes-their-environment?mini=node%2F333%2F2015-11 (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?quicktabs_menu_e2_en=0 (2015-10-10)
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  • Echoes of multiple outbursts of Sagittarius A* revealed by Chandra | UnivEarthS
    Thus the reflected radiation is reaching the Earth with a delay compared to the direct emission from the illuminating object which is already seen about 26 000 years after it is emitted and thus it appears as a light echo of an activity that has been quenched since then If measured in great detail this echo allows us to study the past behavior of the black hole When the high energy radiation hits the cool molecular gas of the cloud it is partly absorbed by the gas and partly scattered away A fraction of the absorbed radiation is re emitted as fluorescence light at specific energies corresponding to the difference of the electron energy levels of the atoms involved in the absorption and re emission processes One characteristic fluorescent line which is expected to be particularly intense is the one corresponding to the first two energy levels of the iron atom at 6 4 keV in the X ray band This X ray line and the associated scattered continuum emission the so called reflection component have been indeed observed by the large space X ray observatories presently in operation notably the European INTEGRAL and XMM Newton satellites and the American Chandra observatory It is emanating from the massive and dense clouds of molecular gas that turn around the center of the Milky Way at distances varying between few tens to thousand light years from it This emission was also already observed to vary and even to propagate with an apparent superluminal speed by the same research team back in 2010 using XMM Newton and was then attributed to the reflection of a long outburst about 300 years long from Sagittarius A see http www2 cnrs fr presse communique 1894 htm Taking advantage of Chandra exceptional high resolution the team of astrophysicists focused on the bright clouds which are less than 100 light years away from Sagittarius A in projection towards the Galactic east in order to explore in greater details the drastic variations of the iron line fluorescent emission during the past decade They found that the observed variations can be described essentially by two different behaviors either a two year peak propagating from west to east in one specific molecular structure called the Bridge or a linear change either increasing or a decreasing for the past ten years in all the other structures Based on the density of the clouds which are reflecting the past emission of Sagittarius A the team concluded that these two behaviors are likely due to two distinct past events of Sagittarius A The animation above presents the main results of the publication The first color image gives a static view of the neutral iron fluorescence line emission at 6 4 keV in the region as seen by Chandra between 1999 and 2011 Both the position of the supermassive black hole Sagittarius A white cross and the angular scale in light years ly are indicated on this image plotted in Galactic coordinates Then the animation

    Original URL path: http://www.univearths.fr/en/echoes-multiple-outbursts-sagittarius-revealed-chandra (2015-10-10)
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  • October 2013: IAU symposium on The Galactic Center: Feeding and Feedback in a Normal Galactic Nucleus, Santa Fe, US | UnivEarthS
    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 Dark Matter Search Post Doctoral Research Fellow IGOSat internship PhD position Effect of the North South dichotomy on the thermal structure and evolution of Mars Search this site October Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Sign in Password forgotten Home October 2013 IAU symposium on The Galactic Center Feeding and Feedback in a Normal Galactic Nucleus Santa Fe US 22 07 2013 This 5 day IAU symposium 303 dedicated to the astrophysics of the Galactic Center will be held in Santa Fe New Mexico USA from 30 Sept 2013 to 4 Oct 2013 The aim is to bring together Galactic center researchers to discuss topics concerning the following questions What are the detailed physical properties of the clouds in the Central Molecular Zone and what is

    Original URL path: http://www.univearths.fr/en/node/392 (2015-10-10)
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