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1. Downward remagnetization of a similar to 74-m-thick zone in lake sediments from palaeo-Lake Idaho (NW United States)-Locating the Gauss/Matuyama geomagnetic boundary within a dual-polarity zone

Author

Allstaedt, Frederik J., Appel, Erwin, Roesler, Wolfgang, Prokopenko, Alexander A., Neumann, Udo, Wenzel, Thomas, Pross, Joerg, Allstaedt, Frederik J., Appel, Erwin, Roesler, Wolfgang, Prokopenko, Alexander A., Neumann, Udo, Wenzel, Thomas, and Pross, Joerg

Abstract

Remagnetization is an important issue in palaeomagnetism. Here, we discuss an extraordinarily thick (similar to 74 m) dual-polarity transition zone between the Gauss and Matuyama Chrons. The studied succession is from a drill core through lacustrine sediments of palaeo-Lake Idaho (Snake River Plain, NW United States of America) that are intercalated with basalt units. We identified detrital Ti-rich titanomagnetite and magnetite in lamellar exsolutions as the main carriers of a primary remanence, likely derived from the basalts that erupted in the Snake River Plain. Stepwise thermal demagnetization revealed a single-component remanent magnetization with reversed and normal polarities above and below the transition zone, respectively. Based on rock-magnetic results, microscopic observations, and previously known events in the evolution of palaeo-Lake Idaho, the reversed-polarity component in the transition zone represents a secondary chemical remanent magnetization caused by magnetic mineral alteration or partial neo-formation of magnetite, in association with strong depletion of the primary detrital magnetic minerals that affected a wide depth range below the level where the remagnetization event occurred. This remagnetization event was most likely related to lake-level lowering and partial desiccation of palaeo-Lake Idaho. Understanding the nature and origin of the remagnetization allows to identify the polarity boundary in the unusual case of a secondary magnetization with reversed polarity produced downward in a sequence to an extraordinary large depth. Based on available age information, the observed reversal represents the Gauss/Matuyama boundary, which provides an important age constraint for palaeoclimatic interpretation of the succession.

Published
2020

2. Downward remagnetization of a similar to 74-m-thick zone in lake sediments from palaeo-Lake Idaho (NW United States)-Locating the Gauss/Matuyama geomagnetic boundary within a dual-polarity zone

Author

Allstaedt, Frederik J., Appel, Erwin, Roesler, Wolfgang, Prokopenko, Alexander A., Neumann, Udo, Wenzel, Thomas, Pross, Joerg, Allstaedt, Frederik J., Appel, Erwin, Roesler, Wolfgang, Prokopenko, Alexander A., Neumann, Udo, Wenzel, Thomas, and Pross, Joerg

Abstract

Remagnetization is an important issue in palaeomagnetism. Here, we discuss an extraordinarily thick (similar to 74 m) dual-polarity transition zone between the Gauss and Matuyama Chrons. The studied succession is from a drill core through lacustrine sediments of palaeo-Lake Idaho (Snake River Plain, NW United States of America) that are intercalated with basalt units. We identified detrital Ti-rich titanomagnetite and magnetite in lamellar exsolutions as the main carriers of a primary remanence, likely derived from the basalts that erupted in the Snake River Plain. Stepwise thermal demagnetization revealed a single-component remanent magnetization with reversed and normal polarities above and below the transition zone, respectively. Based on rock-magnetic results, microscopic observations, and previously known events in the evolution of palaeo-Lake Idaho, the reversed-polarity component in the transition zone represents a secondary chemical remanent magnetization caused by magnetic mineral alteration or partial neo-formation of magnetite, in association with strong depletion of the primary detrital magnetic minerals that affected a wide depth range below the level where the remagnetization event occurred. This remagnetization event was most likely related to lake-level lowering and partial desiccation of palaeo-Lake Idaho. Understanding the nature and origin of the remagnetization allows to identify the polarity boundary in the unusual case of a secondary magnetization with reversed polarity produced downward in a sequence to an extraordinary large depth. Based on available age information, the observed reversal represents the Gauss/Matuyama boundary, which provides an important age constraint for palaeoclimatic interpretation of the succession.

Published
2020

3. Multiple Star Systems in the Orion Nebula

Author

GRAVITY collaboration, Karl, Martina, Pfuhl, Oliver, Eisenhauer, Frank, Genzel, Reinhard, Grellmann, Rebekka, Habibi, Maryam, Abuter, Roberto, Accardo, Matteo, Amorim, António, Anugu, Narsireddy, Ávila, Gerardo, Benisty, Myriam, Berger, Jean-Philippe, Bland, Nicolas, Bonnet, Henri, Bourget, Pierre, Brandner, Wolfgang, Brast, Roland, Buron, Alexander, Garatti, Alessio Caratti o, Chapron, Frédéric, Clénet, Yann, Collin, Claude, Foresto, Vincent Coudé du, de Wit, Willem-Jan, de Zeeuw, Tim, Deen, Casey, Delplancke-Ströbele, Françoise, Dembet, Roderick, Derie, Frédéric, Dexter, Jason, Duvert, Gilles, Ebert, Monica, Eckart, Andreas, Esselborn, Michael, Fédou, Pierre, Finger, Gert, Garcia, Paulo, Dabo, Cesar Enrique Garcia, Lopez, Rebeca Garcia, Gao, Feng, Gandron, Éric, Gillessen, Stefan, Gonté, Frédéric, Gordo, Paulo, Grözinger, Ulrich, Guajardo, Patricia, Guieu, Sylvain, Haguenauer, Pierre, Hans, Oliver, Haubois, Xavier, Haug, Marcus, Haußmann, Frank, Henning, Thomas, Hippler, Stefan, Horrobin, Matthew, Huber, Armin, Hubert, Zoltan, Hubin, Norbert, Hummel, Christian A., Jakob, Gerd, Jochum, Lieselotte, Jocou, Laurent, Kaufer, Andreas, Kellner, Stefan, Kandrew, Sarah, Kern, Lothar, Kervella, Pierre, Kiekebusch, Mario, Klein, Ralf, Köhler, Rainer, Kolb, Johan, Kulas, Martin, Lacour, Sylvestre, Lapeyrère, Vincent, Lazareff, Bernard, Bouquin, Jean-Baptiste Le, Léna, Pierre, Lenzen, Rainer, Lévêque, Samuel, Lin, Chien-Cheng, Lippa, Magdalena, Magnard, Yves, Mehrgan, Leander, Mérand, Antoine, Moulin, Thibaut, Müller, Eric, Müller, Friedrich, Neumann, Udo, Oberti, Sylvain, Ott, Thomas, Pallanca, Laurent, Panduro, Johana, Pasquini, Luca, Paumard, Thibaut, Percheron, Isabelle, Perraut, Karine, Perrin, Guy, Pflüger, Andreas, Duc, Thanh Phan, Plewa, Philipp M., Popovic, Dan, Rabien, Sebastian, Ramírez, Andrés, Ramos, Jose, Rau, Christian, Riquelme, Miguel, Rodríguez-Coira, Gustavo, Rohloff, Ralf-Rainer, Rosales, Alejandra, Rousset, Gérard, Sanchez-Bermudez, Joel, Scheithauer, Silvia, Schöller, Markus, Schuhler, Nicolas, Spyromilio, Jason, Straub, Odele, Straubmeier, Christian, Sturm, Eckhard, Suarez, Marcos, Tristram, Konrad R. W., Ventura, Noel, Vincent, Frédéric, Waisberg, Idel, Wank, Imke, Widmann, Felix, Wieprecht, Ekkehard, Wiest, Michael, Wiezorrek, Erich, Wittkowski, Markus, Woillez, Julien, Wolff, Burkhard, Yazici, Senol, Ziegler, Denis, Zins, Gérard, GRAVITY collaboration, Karl, Martina, Pfuhl, Oliver, Eisenhauer, Frank, Genzel, Reinhard, Grellmann, Rebekka, Habibi, Maryam, Abuter, Roberto, Accardo, Matteo, Amorim, António, Anugu, Narsireddy, Ávila, Gerardo, Benisty, Myriam, Berger, Jean-Philippe, Bland, Nicolas, Bonnet, Henri, Bourget, Pierre, Brandner, Wolfgang, Brast, Roland, Buron, Alexander, Garatti, Alessio Caratti o, Chapron, Frédéric, Clénet, Yann, Collin, Claude, Foresto, Vincent Coudé du, de Wit, Willem-Jan, de Zeeuw, Tim, Deen, Casey, Delplancke-Ströbele, Françoise, Dembet, Roderick, Derie, Frédéric, Dexter, Jason, Duvert, Gilles, Ebert, Monica, Eckart, Andreas, Esselborn, Michael, Fédou, Pierre, Finger, Gert, Garcia, Paulo, Dabo, Cesar Enrique Garcia, Lopez, Rebeca Garcia, Gao, Feng, Gandron, Éric, Gillessen, Stefan, Gonté, Frédéric, Gordo, Paulo, Grözinger, Ulrich, Guajardo, Patricia, Guieu, Sylvain, Haguenauer, Pierre, Hans, Oliver, Haubois, Xavier, Haug, Marcus, Haußmann, Frank, Henning, Thomas, Hippler, Stefan, Horrobin, Matthew, Huber, Armin, Hubert, Zoltan, Hubin, Norbert, Hummel, Christian A., Jakob, Gerd, Jochum, Lieselotte, Jocou, Laurent, Kaufer, Andreas, Kellner, Stefan, Kandrew, Sarah, Kern, Lothar, Kervella, Pierre, Kiekebusch, Mario, Klein, Ralf, Köhler, Rainer, Kolb, Johan, Kulas, Martin, Lacour, Sylvestre, Lapeyrère, Vincent, Lazareff, Bernard, Bouquin, Jean-Baptiste Le, Léna, Pierre, Lenzen, Rainer, Lévêque, Samuel, Lin, Chien-Cheng, Lippa, Magdalena, Magnard, Yves, Mehrgan, Leander, Mérand, Antoine, Moulin, Thibaut, Müller, Eric, Müller, Friedrich, Neumann, Udo, Oberti, Sylvain, Ott, Thomas, Pallanca, Laurent, Panduro, Johana, Pasquini, Luca, Paumard, Thibaut, Percheron, Isabelle, Perraut, Karine, Perrin, Guy, Pflüger, Andreas, Duc, Thanh Phan, Plewa, Philipp M., Popovic, Dan, Rabien, Sebastian, Ramírez, Andrés, Ramos, Jose, Rau, Christian, Riquelme, Miguel, Rodríguez-Coira, Gustavo, Rohloff, Ralf-Rainer, Rosales, Alejandra, Rousset, Gérard, Sanchez-Bermudez, Joel, Scheithauer, Silvia, Schöller, Markus, Schuhler, Nicolas, Spyromilio, Jason, Straub, Odele, Straubmeier, Christian, Sturm, Eckhard, Suarez, Marcos, Tristram, Konrad R. W., Ventura, Noel, Vincent, Frédéric, Waisberg, Idel, Wank, Imke, Widmann, Felix, Wieprecht, Ekkehard, Wiest, Michael, Wiezorrek, Erich, Wittkowski, Markus, Woillez, Julien, Wolff, Burkhard, Yazici, Senol, Ziegler, Denis, and Zins, Gérard

Abstract

This work presents an interferometric study of the massive-binary fraction in the Orion Trapezium Cluster with the recently comissioned GRAVITY instrument. We observe a total of 16 stars of mainly OB spectral type. We find three previously unknown companions for $\theta ^1$ Ori B, $\theta ^2$ Ori B, and $\theta ^2$ Ori C. We determine a separation for the previously suspected companion of NU Ori. We confirm four companions for $\theta ^1$ Ori A, $\theta ^1$ Ori C, $\theta ^1$ Ori D, and $\theta ^2$ Ori A, all with substantially improved astrometry and photometric mass estimates. We refine the orbit of the eccentric high-mass binary $\theta ^1$ Ori C and we are able to derive a new orbit for $\theta ^1$ Ori D. We find a system mass of 21.7 $M_{\odot}$ and a period of $53$ days. Together with other previously detected companions seen in spectroscopy or direct imaging, eleven of the 16 high-mass stars are multiple systems. We obtain a total number of 22 companions with separations up to 600 AU. The companion fraction of the early B and O stars in our sample is about 2, significantly higher than in earlier studies of mostly OB associations. The separation distribution hints towards a bimodality. Such a bimodality has been previously found in A stars, but rarely in OB binaries, which up to this point have been assumed to be mostly compact with a tail of wider companions. We also do not find a substantial population of equal-mass binaries. The observed distribution of mass ratios declines steeply with mass, and like the direct star counts, indicates that our companions follow a standard power law initial mass function. Again, this is in contrast to earlier findings of flat mass ratio distributions in OB associations. We exclude collision as a dominant formation mechanism but find no clear preference for core accretion or competitive accretion., Comment: Accepted for publication in A&A

Published
2018
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4. The MICADO first light imager for the ELT: overview, operation, simulation

Author

Davies, Richard, Alves, João, Clénet, Yann, Lang-Bardl, Florian, Nicklas, Harald, Pott, Jörg-Uwe, Ragazzoni, Roberto, Tolstoy, Eline, Amico, Paola, Anwand-Heerwart, Heiko, Barboza, Santiago, Barl, Lothar, Baudoz, Pierre, Bender, Ralf, Bezawada, Naidu, Bizenberger, Peter, Boland, Wilfried, Bonifacio, Piercarlo, Borgo, Bruno, Buey, Tristan, Chapron, Frédéric, Chemla, Fanny, Cohen, Mathieu, Czoske, Oliver, Deo, Vincent, Disseau, Karen, Dreizler, Stefan, Dupuis, Olivier, Fabricius, Maximilian, Falomo, Renato, Fedou, Pierre, Schreiber, Natascha Foerster, Garrel, Vincent, Geis, Norbert, Gemperlein, Hans, Gendron, Eric, Genzel, Reinhard, Gillessen, Stefan, Glück, Martin, Grupp, Frank, Hartl, Michael, Häuser, Marco, Hess, Hans-Joachim, Hofferbert, Ralf, Hopp, Ulrich, Hörmann, Veronika, Hubert, Zoltan, Huby, Elsa, Huet, Jean-Michel, Hutterer, Victoria, Ives, Derek, Janssen, Annemieke, Jellema, Willem, Kausch, Wolfgang, Kerber, Florian, Kravcar, Helmut, Ruyet, Bertrand Le, Leschinski, Kieran, Mandla, Christopher, Manhart, Markus, Massari, Davide, Mei, Simona, Merlin, Frédéric, Mohr, Lars, Monna, Anna, Muench, Norbert, Mueller, Friedrich, Musters, Gert, Navarro, Ramon, Neumann, Udo, Neumayer, Nadine, Niebsch, Jenny, Plattner, Markus, Przybilla, Norbert, Rabien, Sebastian, Ramlau, Ronny, Ramos, José, Ramsay, Suzanne, Rhode, Petra, Richter, Amon, Richter, Josef, Rix, Hans-Walter, Rodeghiero, Gabriele, Rohloff, Ralf-Rainer, Rosensteiner, Matthias, Rousset, Gérard, Schlichter, Jörg, Schubert, Josef, Sevin, Arnaud, Stuik, Remko, Sturm, Eckhard, Thomas, Jens, Tromp, Niels, Kleijn, Gijs Verdoes, Vidal, Fabrice, Wagner, Roland, Wegner, Michael, Zeilinger, Werner, Ziegleder, Julian, Ziegler, Bodo, Zins, Gérard, Davies, Richard, Alves, João, Clénet, Yann, Lang-Bardl, Florian, Nicklas, Harald, Pott, Jörg-Uwe, Ragazzoni, Roberto, Tolstoy, Eline, Amico, Paola, Anwand-Heerwart, Heiko, Barboza, Santiago, Barl, Lothar, Baudoz, Pierre, Bender, Ralf, Bezawada, Naidu, Bizenberger, Peter, Boland, Wilfried, Bonifacio, Piercarlo, Borgo, Bruno, Buey, Tristan, Chapron, Frédéric, Chemla, Fanny, Cohen, Mathieu, Czoske, Oliver, Deo, Vincent, Disseau, Karen, Dreizler, Stefan, Dupuis, Olivier, Fabricius, Maximilian, Falomo, Renato, Fedou, Pierre, Schreiber, Natascha Foerster, Garrel, Vincent, Geis, Norbert, Gemperlein, Hans, Gendron, Eric, Genzel, Reinhard, Gillessen, Stefan, Glück, Martin, Grupp, Frank, Hartl, Michael, Häuser, Marco, Hess, Hans-Joachim, Hofferbert, Ralf, Hopp, Ulrich, Hörmann, Veronika, Hubert, Zoltan, Huby, Elsa, Huet, Jean-Michel, Hutterer, Victoria, Ives, Derek, Janssen, Annemieke, Jellema, Willem, Kausch, Wolfgang, Kerber, Florian, Kravcar, Helmut, Ruyet, Bertrand Le, Leschinski, Kieran, Mandla, Christopher, Manhart, Markus, Massari, Davide, Mei, Simona, Merlin, Frédéric, Mohr, Lars, Monna, Anna, Muench, Norbert, Mueller, Friedrich, Musters, Gert, Navarro, Ramon, Neumann, Udo, Neumayer, Nadine, Niebsch, Jenny, Plattner, Markus, Przybilla, Norbert, Rabien, Sebastian, Ramlau, Ronny, Ramos, José, Ramsay, Suzanne, Rhode, Petra, Richter, Amon, Richter, Josef, Rix, Hans-Walter, Rodeghiero, Gabriele, Rohloff, Ralf-Rainer, Rosensteiner, Matthias, Rousset, Gérard, Schlichter, Jörg, Schubert, Josef, Sevin, Arnaud, Stuik, Remko, Sturm, Eckhard, Thomas, Jens, Tromp, Niels, Kleijn, Gijs Verdoes, Vidal, Fabrice, Wagner, Roland, Wegner, Michael, Zeilinger, Werner, Ziegleder, Julian, Ziegler, Bodo, and Zins, Gérard

Abstract

MICADO will enable the ELT to perform diffraction limited near-infrared observations at first light. The instrument's capabilities focus on imaging (including astrometric and high contrast) as well as single object spectroscopy. This contribution looks at how requirements from the observing modes have driven the instrument design and functionality. Using examples from specific science cases, and making use of the data simulation tool, an outline is presented of what we can expect the instrument to achieve., Comment: Proc SPIE 10702. SPIE's copyright notice: "Copyright 2018 Society of PhotoOptical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, 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
2018

5. Multiple star systems in the Orion nebula

Author

Karl, Martina, Pfuhl, Oliver, Eisenhauer, Frank, Genzel, Reinhard, Grellmann, Rebekka, Habibi, Maryam, Abuter, Roberto, Accardo, Matteo, Amorim, Antonio, Anugu, Narsireddy, Avila, Gerardo, Benisty, Myriam, Berger, Jean-Philippe, Blind, Nicolas, Bonnet, Henri, Bourget, Pierre, Brandner, Wolfgang, Brast, Roland, Buron, Alexander, Garatti, Alessio Caratti O., Chapron, Frederic, Clenet, Yann, Collin, Claude, du Foresto, Vincent Coude, de Wit, Willem-Jan, de Zeeuw, Tim, Deen, Casey, Delplancke-Stroebele, Francoise, Dembet, Roderick, Derie, Frederic, Dexter, Jason, Duvert, Gilles, Ebert, Monica, Eckart, Andreas, Esselborn, Michael, Fedou, Pierre, Finger, Gert, Garcia, Paulo, Dabo, Cesar Enrique Garcia, Lopez, Rebeca Garcia, Gao, Feng, Gendron, Eric, Gillessen, Stefan, Gonte, Frederic, Gordo, Paulo, Groezinger, Ulrich, Guajardo, Patricia, Guieu, Sylvain, Haguenauer, Pierre, Hans, Oliver, Haubois, Xavier, Haug, Marcus, Haussmann, Frank, Henning, Thomas, Hippler, Stefan, Horrobin, Matthew, Huber, Armin, Hubert, Zoltan, Hubin, Norbert, Jakob, Gerd, Jochum, Lieselotte, Jocou, Laurent, Kaufer, Andreas, Kellner, Stefan, Kendrew, Sarah, Kern, Lothar, Kervella, Pierre, Kiekebusch, Mario, Klein, Ralf, Koehler, Rainer, Kolb, Johan, Kulas, Martin, Lacour, Sylvestre, Lapeyrere, Vincent, Lazareff, Bernard, Le Bouquin, Jean-Baptiste, Lena, Pierre, Lenzen, Rainer, Leveque, Samuel, Lin, Chien-Cheng, Lippa, Magdalena, Magnard, Yves, Mehrgan, Leander, Merand, Antoine, Moulin, Thibaut, Mueller, Eric, Mueller, Friedrich, Neumann, Udo, Oberti, Sylvain, Ott, Thomas, Pallanca, Laurent, Panduro, Johana, Pasquini, Luca, Paumard, Thibaut, Percheron, Isabelle, Perraut, Karine, Perrin, Guy, Pflueger, Andreas, Plewa, Philipp M., Popovic, Dan, Rabien, Sebastian, Ramirez, Andres, Ramos, Jose, Rau, Christian, Riquelme, Miguel, Rodriguez-Coira, Gustavo, Rohloff, Ralf-Rainer, Rosales, Alejandra, Rousset, Gerard, Sanchez-Bermudez, Joel, Scheithauer, Silvia, Schoeller, Markus, Schuhler, Nicolas, Spyromilio, Jason, Straub, Odele, Straubmeier, Christian, Sturm, Eckhard, Suarez, Marcos, Tristram, Konrad R. W., Ventura, Noel, Vincent, Frederic, Waisberg, Idel, Wank, Imke, Widmann, Felix, Wieprecht, Ekkehard, Wiest, Michael, Wiezorrek, Erich, Wittkowski, Markus, Woillez, Julien, Wolff, Burkhard, Yazici, Senol, Ziegler, Denis, Zins, Gerard, Karl, Martina, Pfuhl, Oliver, Eisenhauer, Frank, Genzel, Reinhard, Grellmann, Rebekka, Habibi, Maryam, Abuter, Roberto, Accardo, Matteo, Amorim, Antonio, Anugu, Narsireddy, Avila, Gerardo, Benisty, Myriam, Berger, Jean-Philippe, Blind, Nicolas, Bonnet, Henri, Bourget, Pierre, Brandner, Wolfgang, Brast, Roland, Buron, Alexander, Garatti, Alessio Caratti O., Chapron, Frederic, Clenet, Yann, Collin, Claude, du Foresto, Vincent Coude, de Wit, Willem-Jan, de Zeeuw, Tim, Deen, Casey, Delplancke-Stroebele, Francoise, Dembet, Roderick, Derie, Frederic, Dexter, Jason, Duvert, Gilles, Ebert, Monica, Eckart, Andreas, Esselborn, Michael, Fedou, Pierre, Finger, Gert, Garcia, Paulo, Dabo, Cesar Enrique Garcia, Lopez, Rebeca Garcia, Gao, Feng, Gendron, Eric, Gillessen, Stefan, Gonte, Frederic, Gordo, Paulo, Groezinger, Ulrich, Guajardo, Patricia, Guieu, Sylvain, Haguenauer, Pierre, Hans, Oliver, Haubois, Xavier, Haug, Marcus, Haussmann, Frank, Henning, Thomas, Hippler, Stefan, Horrobin, Matthew, Huber, Armin, Hubert, Zoltan, Hubin, Norbert, Jakob, Gerd, Jochum, Lieselotte, Jocou, Laurent, Kaufer, Andreas, Kellner, Stefan, Kendrew, Sarah, Kern, Lothar, Kervella, Pierre, Kiekebusch, Mario, Klein, Ralf, Koehler, Rainer, Kolb, Johan, Kulas, Martin, Lacour, Sylvestre, Lapeyrere, Vincent, Lazareff, Bernard, Le Bouquin, Jean-Baptiste, Lena, Pierre, Lenzen, Rainer, Leveque, Samuel, Lin, Chien-Cheng, Lippa, Magdalena, Magnard, Yves, Mehrgan, Leander, Merand, Antoine, Moulin, Thibaut, Mueller, Eric, Mueller, Friedrich, Neumann, Udo, Oberti, Sylvain, Ott, Thomas, Pallanca, Laurent, Panduro, Johana, Pasquini, Luca, Paumard, Thibaut, Percheron, Isabelle, Perraut, Karine, Perrin, Guy, Pflueger, Andreas, Plewa, Philipp M., Popovic, Dan, Rabien, Sebastian, Ramirez, Andres, Ramos, Jose, Rau, Christian, Riquelme, Miguel, Rodriguez-Coira, Gustavo, Rohloff, Ralf-Rainer, Rosales, Alejandra, Rousset, Gerard, Sanchez-Bermudez, Joel, Scheithauer, Silvia, Schoeller, Markus, Schuhler, Nicolas, Spyromilio, Jason, Straub, Odele, Straubmeier, Christian, Sturm, Eckhard, Suarez, Marcos, Tristram, Konrad R. W., Ventura, Noel, Vincent, Frederic, Waisberg, Idel, Wank, Imke, Widmann, Felix, Wieprecht, Ekkehard, Wiest, Michael, Wiezorrek, Erich, Wittkowski, Markus, Woillez, Julien, Wolff, Burkhard, Yazici, Senol, Ziegler, Denis, and Zins, Gerard

Abstract

This work presents an interferometric study of the massive-binary fraction in the Orion Trapezium cluster with the recently comissioned GRAVITY instrument. We observed a total of 16 stars of mainly OB spectral type. We find three previously unknown companions for theta(1) Ori B, theta(2) Ori B, and theta(2) Ori C. We determined a separation for the previously suspected companion of NU Ori. We confirm four companions for theta(1) Ori A, theta(1) Ori C, theta(1) Ori D, and theta(2) Ori A, all with substantially improved astrometry and photometric mass estimates. We refined the orbit of the eccentric high-mass binary theta(1) Ori C and we are able to derive a new orbit for theta(1) Ori D. We find a system mass of 21.7 M-circle dot and a period of 53 days. Together with other previously detected companions seen in spectroscopy or direct imaging, eleven of the 16 high-mass stars are multiple systems. We obtain a total number of 22 companions with separations up to 600 AU. The companion fraction of the early B and O stars in our sample is about two, significantly higher than in earlier studies of mostly OB associations. The separation distribution hints toward a bimodality. Such a bimodality has been previously found in A stars, but rarely in OB binaries, which up to this point have been assumed to be mostly compact with a tail of wider companions. We also do not find a substantial population of equal-mass binaries. The observed distribution of mass ratios declines steeply with mass, and like the direct star counts, indicates that our companions follow a standard power law initial mass function. Again, this is in contrast to earlier findings of flat mass ratio distributions in OB associations. We excluded collision as a dominant formation mechanism but find no clear preference for core accretion or competitive accretion.

Published
2018

6. Multiple star systems in the Orion nebula

Author

Karl, Martina, Pfuhl, Oliver, Eisenhauer, Frank, Genzel, Reinhard, Grellmann, Rebekka, Habibi, Maryam, Abuter, Roberto, Accardo, Matteo, Amorim, Antonio, Anugu, Narsireddy, Avila, Gerardo, Benisty, Myriam, Berger, Jean-Philippe, Blind, Nicolas, Bonnet, Henri, Bourget, Pierre, Brandner, Wolfgang, Brast, Roland, Buron, Alexander, Garatti, Alessio Caratti O., Chapron, Frederic, Clenet, Yann, Collin, Claude, du Foresto, Vincent Coude, de Wit, Willem-Jan, de Zeeuw, Tim, Deen, Casey, Delplancke-Stroebele, Francoise, Dembet, Roderick, Derie, Frederic, Dexter, Jason, Duvert, Gilles, Ebert, Monica, Eckart, Andreas, Esselborn, Michael, Fedou, Pierre, Finger, Gert, Garcia, Paulo, Dabo, Cesar Enrique Garcia, Lopez, Rebeca Garcia, Gao, Feng, Gendron, Eric, Gillessen, Stefan, Gonte, Frederic, Gordo, Paulo, Groezinger, Ulrich, Guajardo, Patricia, Guieu, Sylvain, Haguenauer, Pierre, Hans, Oliver, Haubois, Xavier, Haug, Marcus, Haussmann, Frank, Henning, Thomas, Hippler, Stefan, Horrobin, Matthew, Huber, Armin, Hubert, Zoltan, Hubin, Norbert, Jakob, Gerd, Jochum, Lieselotte, Jocou, Laurent, Kaufer, Andreas, Kellner, Stefan, Kendrew, Sarah, Kern, Lothar, Kervella, Pierre, Kiekebusch, Mario, Klein, Ralf, Koehler, Rainer, Kolb, Johan, Kulas, Martin, Lacour, Sylvestre, Lapeyrere, Vincent, Lazareff, Bernard, Le Bouquin, Jean-Baptiste, Lena, Pierre, Lenzen, Rainer, Leveque, Samuel, Lin, Chien-Cheng, Lippa, Magdalena, Magnard, Yves, Mehrgan, Leander, Merand, Antoine, Moulin, Thibaut, Mueller, Eric, Mueller, Friedrich, Neumann, Udo, Oberti, Sylvain, Ott, Thomas, Pallanca, Laurent, Panduro, Johana, Pasquini, Luca, Paumard, Thibaut, Percheron, Isabelle, Perraut, Karine, Perrin, Guy, Pflueger, Andreas, Plewa, Philipp M., Popovic, Dan, Rabien, Sebastian, Ramirez, Andres, Ramos, Jose, Rau, Christian, Riquelme, Miguel, Rodriguez-Coira, Gustavo, Rohloff, Ralf-Rainer, Rosales, Alejandra, Rousset, Gerard, Sanchez-Bermudez, Joel, Scheithauer, Silvia, Schoeller, Markus, Schuhler, Nicolas, Spyromilio, Jason, Straub, Odele, Straubmeier, Christian, Sturm, Eckhard, Suarez, Marcos, Tristram, Konrad R. W., Ventura, Noel, Vincent, Frederic, Waisberg, Idel, Wank, Imke, Widmann, Felix, Wieprecht, Ekkehard, Wiest, Michael, Wiezorrek, Erich, Wittkowski, Markus, Woillez, Julien, Wolff, Burkhard, Yazici, Senol, Ziegler, Denis, Zins, Gerard, Karl, Martina, Pfuhl, Oliver, Eisenhauer, Frank, Genzel, Reinhard, Grellmann, Rebekka, Habibi, Maryam, Abuter, Roberto, Accardo, Matteo, Amorim, Antonio, Anugu, Narsireddy, Avila, Gerardo, Benisty, Myriam, Berger, Jean-Philippe, Blind, Nicolas, Bonnet, Henri, Bourget, Pierre, Brandner, Wolfgang, Brast, Roland, Buron, Alexander, Garatti, Alessio Caratti O., Chapron, Frederic, Clenet, Yann, Collin, Claude, du Foresto, Vincent Coude, de Wit, Willem-Jan, de Zeeuw, Tim, Deen, Casey, Delplancke-Stroebele, Francoise, Dembet, Roderick, Derie, Frederic, Dexter, Jason, Duvert, Gilles, Ebert, Monica, Eckart, Andreas, Esselborn, Michael, Fedou, Pierre, Finger, Gert, Garcia, Paulo, Dabo, Cesar Enrique Garcia, Lopez, Rebeca Garcia, Gao, Feng, Gendron, Eric, Gillessen, Stefan, Gonte, Frederic, Gordo, Paulo, Groezinger, Ulrich, Guajardo, Patricia, Guieu, Sylvain, Haguenauer, Pierre, Hans, Oliver, Haubois, Xavier, Haug, Marcus, Haussmann, Frank, Henning, Thomas, Hippler, Stefan, Horrobin, Matthew, Huber, Armin, Hubert, Zoltan, Hubin, Norbert, Jakob, Gerd, Jochum, Lieselotte, Jocou, Laurent, Kaufer, Andreas, Kellner, Stefan, Kendrew, Sarah, Kern, Lothar, Kervella, Pierre, Kiekebusch, Mario, Klein, Ralf, Koehler, Rainer, Kolb, Johan, Kulas, Martin, Lacour, Sylvestre, Lapeyrere, Vincent, Lazareff, Bernard, Le Bouquin, Jean-Baptiste, Lena, Pierre, Lenzen, Rainer, Leveque, Samuel, Lin, Chien-Cheng, Lippa, Magdalena, Magnard, Yves, Mehrgan, Leander, Merand, Antoine, Moulin, Thibaut, Mueller, Eric, Mueller, Friedrich, Neumann, Udo, Oberti, Sylvain, Ott, Thomas, Pallanca, Laurent, Panduro, Johana, Pasquini, Luca, Paumard, Thibaut, Percheron, Isabelle, Perraut, Karine, Perrin, Guy, Pflueger, Andreas, Plewa, Philipp M., Popovic, Dan, Rabien, Sebastian, Ramirez, Andres, Ramos, Jose, Rau, Christian, Riquelme, Miguel, Rodriguez-Coira, Gustavo, Rohloff, Ralf-Rainer, Rosales, Alejandra, Rousset, Gerard, Sanchez-Bermudez, Joel, Scheithauer, Silvia, Schoeller, Markus, Schuhler, Nicolas, Spyromilio, Jason, Straub, Odele, Straubmeier, Christian, Sturm, Eckhard, Suarez, Marcos, Tristram, Konrad R. W., Ventura, Noel, Vincent, Frederic, Waisberg, Idel, Wank, Imke, Widmann, Felix, Wieprecht, Ekkehard, Wiest, Michael, Wiezorrek, Erich, Wittkowski, Markus, Woillez, Julien, Wolff, Burkhard, Yazici, Senol, Ziegler, Denis, and Zins, Gerard

Abstract

This work presents an interferometric study of the massive-binary fraction in the Orion Trapezium cluster with the recently comissioned GRAVITY instrument. We observed a total of 16 stars of mainly OB spectral type. We find three previously unknown companions for theta(1) Ori B, theta(2) Ori B, and theta(2) Ori C. We determined a separation for the previously suspected companion of NU Ori. We confirm four companions for theta(1) Ori A, theta(1) Ori C, theta(1) Ori D, and theta(2) Ori A, all with substantially improved astrometry and photometric mass estimates. We refined the orbit of the eccentric high-mass binary theta(1) Ori C and we are able to derive a new orbit for theta(1) Ori D. We find a system mass of 21.7 M-circle dot and a period of 53 days. Together with other previously detected companions seen in spectroscopy or direct imaging, eleven of the 16 high-mass stars are multiple systems. We obtain a total number of 22 companions with separations up to 600 AU. The companion fraction of the early B and O stars in our sample is about two, significantly higher than in earlier studies of mostly OB associations. The separation distribution hints toward a bimodality. Such a bimodality has been previously found in A stars, but rarely in OB binaries, which up to this point have been assumed to be mostly compact with a tail of wider companions. We also do not find a substantial population of equal-mass binaries. The observed distribution of mass ratios declines steeply with mass, and like the direct star counts, indicates that our companions follow a standard power law initial mass function. Again, this is in contrast to earlier findings of flat mass ratio distributions in OB associations. We excluded collision as a dominant formation mechanism but find no clear preference for core accretion or competitive accretion.

Published
2018

7. Multiple Star Systems in the Orion Nebula

Author

GRAVITY collaboration, Karl, Martina, Pfuhl, Oliver, Eisenhauer, Frank, Genzel, Reinhard, Grellmann, Rebekka, Habibi, Maryam, Abuter, Roberto, Accardo, Matteo, Amorim, António, Anugu, Narsireddy, Ávila, Gerardo, Benisty, Myriam, Berger, Jean-Philippe, Bland, Nicolas, Bonnet, Henri, Bourget, Pierre, Brandner, Wolfgang, Brast, Roland, Buron, Alexander, Garatti, Alessio Caratti o, Chapron, Frédéric, Clénet, Yann, Collin, Claude, Foresto, Vincent Coudé du, de Wit, Willem-Jan, de Zeeuw, Tim, Deen, Casey, Delplancke-Ströbele, Françoise, Dembet, Roderick, Derie, Frédéric, Dexter, Jason, Duvert, Gilles, Ebert, Monica, Eckart, Andreas, Esselborn, Michael, Fédou, Pierre, Finger, Gert, Garcia, Paulo, Dabo, Cesar Enrique Garcia, Lopez, Rebeca Garcia, Gao, Feng, Gandron, Éric, Gillessen, Stefan, Gonté, Frédéric, Gordo, Paulo, Grözinger, Ulrich, Guajardo, Patricia, Guieu, Sylvain, Haguenauer, Pierre, Hans, Oliver, Haubois, Xavier, Haug, Marcus, Haußmann, Frank, Henning, Thomas, Hippler, Stefan, Horrobin, Matthew, Huber, Armin, Hubert, Zoltan, Hubin, Norbert, Hummel, Christian A., Jakob, Gerd, Jochum, Lieselotte, Jocou, Laurent, Kaufer, Andreas, Kellner, Stefan, Kandrew, Sarah, Kern, Lothar, Kervella, Pierre, Kiekebusch, Mario, Klein, Ralf, Köhler, Rainer, Kolb, Johan, Kulas, Martin, Lacour, Sylvestre, Lapeyrère, Vincent, Lazareff, Bernard, Bouquin, Jean-Baptiste Le, Léna, Pierre, Lenzen, Rainer, Lévêque, Samuel, Lin, Chien-Cheng, Lippa, Magdalena, Magnard, Yves, Mehrgan, Leander, Mérand, Antoine, Moulin, Thibaut, Müller, Eric, Müller, Friedrich, Neumann, Udo, Oberti, Sylvain, Ott, Thomas, Pallanca, Laurent, Panduro, Johana, Pasquini, Luca, Paumard, Thibaut, Percheron, Isabelle, Perraut, Karine, Perrin, Guy, Pflüger, Andreas, Duc, Thanh Phan, Plewa, Philipp M., Popovic, Dan, Rabien, Sebastian, Ramírez, Andrés, Ramos, Jose, Rau, Christian, Riquelme, Miguel, Rodríguez-Coira, Gustavo, Rohloff, Ralf-Rainer, Rosales, Alejandra, Rousset, Gérard, Sanchez-Bermudez, Joel, Scheithauer, Silvia, Schöller, Markus, Schuhler, Nicolas, Spyromilio, Jason, Straub, Odele, Straubmeier, Christian, Sturm, Eckhard, Suarez, Marcos, Tristram, Konrad R. W., Ventura, Noel, Vincent, Frédéric, Waisberg, Idel, Wank, Imke, Widmann, Felix, Wieprecht, Ekkehard, Wiest, Michael, Wiezorrek, Erich, Wittkowski, Markus, Woillez, Julien, Wolff, Burkhard, Yazici, Senol, Ziegler, Denis, Zins, Gérard, GRAVITY collaboration, Karl, Martina, Pfuhl, Oliver, Eisenhauer, Frank, Genzel, Reinhard, Grellmann, Rebekka, Habibi, Maryam, Abuter, Roberto, Accardo, Matteo, Amorim, António, Anugu, Narsireddy, Ávila, Gerardo, Benisty, Myriam, Berger, Jean-Philippe, Bland, Nicolas, Bonnet, Henri, Bourget, Pierre, Brandner, Wolfgang, Brast, Roland, Buron, Alexander, Garatti, Alessio Caratti o, Chapron, Frédéric, Clénet, Yann, Collin, Claude, Foresto, Vincent Coudé du, de Wit, Willem-Jan, de Zeeuw, Tim, Deen, Casey, Delplancke-Ströbele, Françoise, Dembet, Roderick, Derie, Frédéric, Dexter, Jason, Duvert, Gilles, Ebert, Monica, Eckart, Andreas, Esselborn, Michael, Fédou, Pierre, Finger, Gert, Garcia, Paulo, Dabo, Cesar Enrique Garcia, Lopez, Rebeca Garcia, Gao, Feng, Gandron, Éric, Gillessen, Stefan, Gonté, Frédéric, Gordo, Paulo, Grözinger, Ulrich, Guajardo, Patricia, Guieu, Sylvain, Haguenauer, Pierre, Hans, Oliver, Haubois, Xavier, Haug, Marcus, Haußmann, Frank, Henning, Thomas, Hippler, Stefan, Horrobin, Matthew, Huber, Armin, Hubert, Zoltan, Hubin, Norbert, Hummel, Christian A., Jakob, Gerd, Jochum, Lieselotte, Jocou, Laurent, Kaufer, Andreas, Kellner, Stefan, Kandrew, Sarah, Kern, Lothar, Kervella, Pierre, Kiekebusch, Mario, Klein, Ralf, Köhler, Rainer, Kolb, Johan, Kulas, Martin, Lacour, Sylvestre, Lapeyrère, Vincent, Lazareff, Bernard, Bouquin, Jean-Baptiste Le, Léna, Pierre, Lenzen, Rainer, Lévêque, Samuel, Lin, Chien-Cheng, Lippa, Magdalena, Magnard, Yves, Mehrgan, Leander, Mérand, Antoine, Moulin, Thibaut, Müller, Eric, Müller, Friedrich, Neumann, Udo, Oberti, Sylvain, Ott, Thomas, Pallanca, Laurent, Panduro, Johana, Pasquini, Luca, Paumard, Thibaut, Percheron, Isabelle, Perraut, Karine, Perrin, Guy, Pflüger, Andreas, Duc, Thanh Phan, Plewa, Philipp M., Popovic, Dan, Rabien, Sebastian, Ramírez, Andrés, Ramos, Jose, Rau, Christian, Riquelme, Miguel, Rodríguez-Coira, Gustavo, Rohloff, Ralf-Rainer, Rosales, Alejandra, Rousset, Gérard, Sanchez-Bermudez, Joel, Scheithauer, Silvia, Schöller, Markus, Schuhler, Nicolas, Spyromilio, Jason, Straub, Odele, Straubmeier, Christian, Sturm, Eckhard, Suarez, Marcos, Tristram, Konrad R. W., Ventura, Noel, Vincent, Frédéric, Waisberg, Idel, Wank, Imke, Widmann, Felix, Wieprecht, Ekkehard, Wiest, Michael, Wiezorrek, Erich, Wittkowski, Markus, Woillez, Julien, Wolff, Burkhard, Yazici, Senol, Ziegler, Denis, and Zins, Gérard

Abstract

This work presents an interferometric study of the massive-binary fraction in the Orion Trapezium Cluster with the recently comissioned GRAVITY instrument. We observe a total of 16 stars of mainly OB spectral type. We find three previously unknown companions for $\theta ^1$ Ori B, $\theta ^2$ Ori B, and $\theta ^2$ Ori C. We determine a separation for the previously suspected companion of NU Ori. We confirm four companions for $\theta ^1$ Ori A, $\theta ^1$ Ori C, $\theta ^1$ Ori D, and $\theta ^2$ Ori A, all with substantially improved astrometry and photometric mass estimates. We refine the orbit of the eccentric high-mass binary $\theta ^1$ Ori C and we are able to derive a new orbit for $\theta ^1$ Ori D. We find a system mass of 21.7 $M_{\odot}$ and a period of $53$ days. Together with other previously detected companions seen in spectroscopy or direct imaging, eleven of the 16 high-mass stars are multiple systems. We obtain a total number of 22 companions with separations up to 600 AU. The companion fraction of the early B and O stars in our sample is about 2, significantly higher than in earlier studies of mostly OB associations. The separation distribution hints towards a bimodality. Such a bimodality has been previously found in A stars, but rarely in OB binaries, which up to this point have been assumed to be mostly compact with a tail of wider companions. We also do not find a substantial population of equal-mass binaries. The observed distribution of mass ratios declines steeply with mass, and like the direct star counts, indicates that our companions follow a standard power law initial mass function. Again, this is in contrast to earlier findings of flat mass ratio distributions in OB associations. We exclude collision as a dominant formation mechanism but find no clear preference for core accretion or competitive accretion., Comment: Accepted for publication in A&A

Published
2018
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8. The MICADO first light imager for the ELT: overview, operation, simulation

Author

Davies, Richard, Alves, João, Clénet, Yann, Lang-Bardl, Florian, Nicklas, Harald, Pott, Jörg-Uwe, Ragazzoni, Roberto, Tolstoy, Eline, Amico, Paola, Anwand-Heerwart, Heiko, Barboza, Santiago, Barl, Lothar, Baudoz, Pierre, Bender, Ralf, Bezawada, Naidu, Bizenberger, Peter, Boland, Wilfried, Bonifacio, Piercarlo, Borgo, Bruno, Buey, Tristan, Chapron, Frédéric, Chemla, Fanny, Cohen, Mathieu, Czoske, Oliver, Deo, Vincent, Disseau, Karen, Dreizler, Stefan, Dupuis, Olivier, Fabricius, Maximilian, Falomo, Renato, Fedou, Pierre, Schreiber, Natascha Foerster, Garrel, Vincent, Geis, Norbert, Gemperlein, Hans, Gendron, Eric, Genzel, Reinhard, Gillessen, Stefan, Glück, Martin, Grupp, Frank, Hartl, Michael, Häuser, Marco, Hess, Hans-Joachim, Hofferbert, Ralf, Hopp, Ulrich, Hörmann, Veronika, Hubert, Zoltan, Huby, Elsa, Huet, Jean-Michel, Hutterer, Victoria, Ives, Derek, Janssen, Annemieke, Jellema, Willem, Kausch, Wolfgang, Kerber, Florian, Kravcar, Helmut, Ruyet, Bertrand Le, Leschinski, Kieran, Mandla, Christopher, Manhart, Markus, Massari, Davide, Mei, Simona, Merlin, Frédéric, Mohr, Lars, Monna, Anna, Muench, Norbert, Mueller, Friedrich, Musters, Gert, Navarro, Ramon, Neumann, Udo, Neumayer, Nadine, Niebsch, Jenny, Plattner, Markus, Przybilla, Norbert, Rabien, Sebastian, Ramlau, Ronny, Ramos, José, Ramsay, Suzanne, Rhode, Petra, Richter, Amon, Richter, Josef, Rix, Hans-Walter, Rodeghiero, Gabriele, Rohloff, Ralf-Rainer, Rosensteiner, Matthias, Rousset, Gérard, Schlichter, Jörg, Schubert, Josef, Sevin, Arnaud, Stuik, Remko, Sturm, Eckhard, Thomas, Jens, Tromp, Niels, Kleijn, Gijs Verdoes, Vidal, Fabrice, Wagner, Roland, Wegner, Michael, Zeilinger, Werner, Ziegleder, Julian, Ziegler, Bodo, Zins, Gérard, Davies, Richard, Alves, João, Clénet, Yann, Lang-Bardl, Florian, Nicklas, Harald, Pott, Jörg-Uwe, Ragazzoni, Roberto, Tolstoy, Eline, Amico, Paola, Anwand-Heerwart, Heiko, Barboza, Santiago, Barl, Lothar, Baudoz, Pierre, Bender, Ralf, Bezawada, Naidu, Bizenberger, Peter, Boland, Wilfried, Bonifacio, Piercarlo, Borgo, Bruno, Buey, Tristan, Chapron, Frédéric, Chemla, Fanny, Cohen, Mathieu, Czoske, Oliver, Deo, Vincent, Disseau, Karen, Dreizler, Stefan, Dupuis, Olivier, Fabricius, Maximilian, Falomo, Renato, Fedou, Pierre, Schreiber, Natascha Foerster, Garrel, Vincent, Geis, Norbert, Gemperlein, Hans, Gendron, Eric, Genzel, Reinhard, Gillessen, Stefan, Glück, Martin, Grupp, Frank, Hartl, Michael, Häuser, Marco, Hess, Hans-Joachim, Hofferbert, Ralf, Hopp, Ulrich, Hörmann, Veronika, Hubert, Zoltan, Huby, Elsa, Huet, Jean-Michel, Hutterer, Victoria, Ives, Derek, Janssen, Annemieke, Jellema, Willem, Kausch, Wolfgang, Kerber, Florian, Kravcar, Helmut, Ruyet, Bertrand Le, Leschinski, Kieran, Mandla, Christopher, Manhart, Markus, Massari, Davide, Mei, Simona, Merlin, Frédéric, Mohr, Lars, Monna, Anna, Muench, Norbert, Mueller, Friedrich, Musters, Gert, Navarro, Ramon, Neumann, Udo, Neumayer, Nadine, Niebsch, Jenny, Plattner, Markus, Przybilla, Norbert, Rabien, Sebastian, Ramlau, Ronny, Ramos, José, Ramsay, Suzanne, Rhode, Petra, Richter, Amon, Richter, Josef, Rix, Hans-Walter, Rodeghiero, Gabriele, Rohloff, Ralf-Rainer, Rosensteiner, Matthias, Rousset, Gérard, Schlichter, Jörg, Schubert, Josef, Sevin, Arnaud, Stuik, Remko, Sturm, Eckhard, Thomas, Jens, Tromp, Niels, Kleijn, Gijs Verdoes, Vidal, Fabrice, Wagner, Roland, Wegner, Michael, Zeilinger, Werner, Ziegleder, Julian, Ziegler, Bodo, and Zins, Gérard

Abstract

MICADO will enable the ELT to perform diffraction limited near-infrared observations at first light. The instrument's capabilities focus on imaging (including astrometric and high contrast) as well as single object spectroscopy. This contribution looks at how requirements from the observing modes have driven the instrument design and functionality. Using examples from specific science cases, and making use of the data simulation tool, an outline is presented of what we can expect the instrument to achieve., Comment: Proc SPIE 10702. SPIE's copyright notice: "Copyright 2018 Society of PhotoOptical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, 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
2018

9. Simulating Precambrian banded iron formation diagenesis

Author

Bekker, Andrey, Kasting, James, Anbar, Ariel, Posth, Nicole R., K??hler, Inga, D. Swanner, Elizabeth, Schr??der, Christian, Wellmann, Eva, Binder, Bernd, Konhauser, Kurt O., Neumann, Udo, Berthold, Christoph, Nowak, Marcus, Kappler, Andreas, Bekker, Andrey, Kasting, James, Anbar, Ariel, Posth, Nicole R., K??hler, Inga, D. Swanner, Elizabeth, Schr??der, Christian, Wellmann, Eva, Binder, Bernd, Konhauser, Kurt O., Neumann, Udo, Berthold, Christoph, Nowak, Marcus, and Kappler, Andreas

Abstract

Post-depositional diagenetic alteration makes the accurate interpretation of key precipitation processes in ancient sediments, such as Precambrian banded iron formations (BIFs), difficult. While microorganisms are proposed as key contributors to BIF deposition, the diagenetic transformation of precursor Fe(III) minerals associated with microbial biomass had not been experimentally tested. We incubated mixtures of ferrihydrite (proxy for biogenic ferric oxyhydroxide minerals) and glucose (proxy for microbial biomass) in gold capsules at 1.2kbar and 170??C. Both wet chemical analysis and mineralogical methods (microscopy, X-ray diffraction and M??ssbauer spectroscopy) were used to analyze the reaction products. Under these conditions, ferrihydrite (FeIII(OH)3) transforms to hematite (Fe2IIIO3), magnetite (FeIIFe2IIIO4), and siderite (FeIICO3). Silica-coated ferrihydrite prepared at conservative Si:Fe ratios (as predicted for the Precambrian oceans) and mixed with glucose yielded hematite and siderite, whereas magnetite could not be identified microscopically. Our results show that electron transfer from organic carbon to Fe(III) minerals during temperature/pressure diagenesis can drive the production of key BIF minerals. Our results also demonstrate that the post-depositional mineralogy of BIF does not directly archive the oceanic or atmospheric conditions present on Earth during their lithification. As a consequence, atmospheric composition regarding concentrations of methane and CO2 during the time of BIF mineral deposition cannot be directly inferred from BIF mineralogical data alone. ?? 2013 Elsevier B.V.

Published
2013

10. Simulating Precambrian banded iron formation diagenesis

Author

Bekker, Andrey, Kasting, James, Anbar, Ariel, Posth, Nicole R., K??hler, Inga, D. Swanner, Elizabeth, Schr??der, Christian, Wellmann, Eva, Binder, Bernd, Konhauser, Kurt O., Neumann, Udo, Berthold, Christoph, Nowak, Marcus, Kappler, Andreas, Bekker, Andrey, Kasting, James, Anbar, Ariel, Posth, Nicole R., K??hler, Inga, D. Swanner, Elizabeth, Schr??der, Christian, Wellmann, Eva, Binder, Bernd, Konhauser, Kurt O., Neumann, Udo, Berthold, Christoph, Nowak, Marcus, and Kappler, Andreas

Abstract

Post-depositional diagenetic alteration makes the accurate interpretation of key precipitation processes in ancient sediments, such as Precambrian banded iron formations (BIFs), difficult. While microorganisms are proposed as key contributors to BIF deposition, the diagenetic transformation of precursor Fe(III) minerals associated with microbial biomass had not been experimentally tested. We incubated mixtures of ferrihydrite (proxy for biogenic ferric oxyhydroxide minerals) and glucose (proxy for microbial biomass) in gold capsules at 1.2kbar and 170??C. Both wet chemical analysis and mineralogical methods (microscopy, X-ray diffraction and M??ssbauer spectroscopy) were used to analyze the reaction products. Under these conditions, ferrihydrite (FeIII(OH)3) transforms to hematite (Fe2IIIO3), magnetite (FeIIFe2IIIO4), and siderite (FeIICO3). Silica-coated ferrihydrite prepared at conservative Si:Fe ratios (as predicted for the Precambrian oceans) and mixed with glucose yielded hematite and siderite, whereas magnetite could not be identified microscopically. Our results show that electron transfer from organic carbon to Fe(III) minerals during temperature/pressure diagenesis can drive the production of key BIF minerals. Our results also demonstrate that the post-depositional mineralogy of BIF does not directly archive the oceanic or atmospheric conditions present on Earth during their lithification. As a consequence, atmospheric composition regarding concentrations of methane and CO2 during the time of BIF mineral deposition cannot be directly inferred from BIF mineralogical data alone. ?? 2013 Elsevier B.V.

Published
2013

11. The GRAVITY Coud\'e Infrared Adaptive Optics (CIAO) system for the VLT Interferometer

Author

Kendrew, Sarah, Hippler, Stefan, Brandner, Wolfgang, Clénet, Yann, Deen, Casey, Gendron, Eric, Huber, Armin, Klein, Ralf, Laun, Werner, Lenzen, Rainer, Naranjo, Vianak, Neumann, Udo, Ramos, José, Rohloff, Ralf-Rainer, Yang, Pengqian, Eisenhauer, Frank, Fedrigo, Enrico, Suarez-Valles, Marcos, Amorim, Antonio, Perraut, Karine, Perrin, Guy, Straubmeier, Christian, Kendrew, Sarah, Hippler, Stefan, Brandner, Wolfgang, Clénet, Yann, Deen, Casey, Gendron, Eric, Huber, Armin, Klein, Ralf, Laun, Werner, Lenzen, Rainer, Naranjo, Vianak, Neumann, Udo, Ramos, José, Rohloff, Ralf-Rainer, Yang, Pengqian, Eisenhauer, Frank, Fedrigo, Enrico, Suarez-Valles, Marcos, Amorim, Antonio, Perraut, Karine, Perrin, Guy, and Straubmeier, Christian

Abstract

GRAVITY is a second generation instrument for the VLT Interferometer, designed to enhance the near-infrared astrometric and spectro-imaging capabilities of VLTI. Combining beams from four telescopes, GRAVITY will provide an astrometric precision of order 10 micro-arcseconds, imaging resolution of 4 milli-arcseconds, and low and medium resolution spectro-interferometry, pushing its performance far beyond current infrared interfero- metric capabilities. To maximise the performance of GRAVITY, adaptive optics correction will be implemented at each of the VLT Unit Telescopes to correct for the effects of atmospheric turbulence. To achieve this, the GRAVITY project includes a development programme for four new wavefront sensors (WFS) and NIR-optimized real time control system. These devices will enable closed-loop adaptive correction at the four Unit Telescopes in the range 1.4-2.4 {\mu}m. This is crucially important for an efficient adaptive optics implementation in regions where optically bright references sources are scarce, such as the Galactic Centre. We present here the design of the GRAVITY wavefront sensors and give an overview of the expected adaptive optics performance under typical observing conditions. Benefiting from newly developed SELEX/ESO SAPHIRA electron avalanche photodiode (eAPD) detectors providing fast readout with low noise in the near-infrared, the AO systems are expected to achieve residual wavefront errors of \leq400 nm at an operating frequency of 500 Hz., Comment: to be published in Proc. SPIE vol. 8446 (2012)

Published
2012
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12. Menschen in extremer Armut: im Auftrag des Bundesministeriums für Gesundheit und Soziale Sicherung

Author

ISL Sozialforschung, Bundesministerium für Gesundheit und Soziale Sicherung, Neumann, Udo, Mingot, Karl, Ludwig, Monika, ISL Sozialforschung, Bundesministerium für Gesundheit und Soziale Sicherung, Neumann, Udo, Mingot, Karl, and Ludwig, Monika

Abstract

"Im Rahmen einer qualitativ explorativen Studie werden extreme Formen der Armut in der Bundesrepublik Deutschland untersucht. Dazu wird anhand biographischer Interviews mit Menschen in prekären Versorgungslagen eine operationale Definition 'extrem Armer' entwickelt, die es erlaubt, extrem Arme zu identifizieren und umfassend zu erforschen. In dieser Untersuchung gilt als extrem arm ein in Deutschland lebender Mensch, der den minimalen Lebensstandard eines in Deutschland Lebenden deutlich unterschreitet und diese Lebenslage nicht aus eigener Kraft verlassen kann. Die Studie arbeitet danach mit einer Armutskonzeption, in der sowohl die 'Lebenslage' als auch die 'Ressourcen' des Einzelnen maßgebend sind. Der Begriff der Ressource wird dabei weit gefasst - viel weiter als im Ressourcenansatz der etablierten Armutsforschung: Er beinhaltet Vermögenswerte, Qualifikationen und Erfahrungen, den Zugang zu Leistungen sozialer Netzwerke, die Möglichkeit des Zugriffs auf Leistungen des sozialen Hilfesystems der Bundesrepublik Deutschland - um die wichtigsten Teilgrößen zu nennen. Der Eintritt in extreme Armut wird - da das Hilfesystem der Bundesrepublik Deutschland Anspruchsberechtigten in Notlagen Hilfen bereitstellt, mit denen sie den minimalen Lebensstandard nicht oder allenfalls kurzzeitig unterschreiten müssen - in engem Zusammenhang mit dem Hilfesystem gesehen: Wird eine Person extrem arm, so hat dies damit zu tun, dass es in einer Notsituation bzw. bei drohendem Eintritt einer solchen Notsituation zwischen ihr und dem sozialen Hilfesystem nicht zu einer fruchtbaren Kooperation kommt, aufgrund derer mit Unterstützung des Hilfesystems der Schritt in extreme Armut verhindert würde. Die Studie präsentiert als zentrale Ergebnisse zwei Typologien, die dieser Überlegung Rechnung tragen: 'Der Schritt in die extreme Armut und das soziale Hilfesystem' (fünf Typen) und 'Extrem Arme und ihre Perspektive' (vier Typen). Im Anschluss an diese explorative Studie wird im Rahmen einer quan

Published
2012

13. The GRAVITY Coud\'e Infrared Adaptive Optics (CIAO) system for the VLT Interferometer

Author

Kendrew, Sarah, Hippler, Stefan, Brandner, Wolfgang, Clénet, Yann, Deen, Casey, Gendron, Eric, Huber, Armin, Klein, Ralf, Laun, Werner, Lenzen, Rainer, Naranjo, Vianak, Neumann, Udo, Ramos, José, Rohloff, Ralf-Rainer, Yang, Pengqian, Eisenhauer, Frank, Fedrigo, Enrico, Suarez-Valles, Marcos, Amorim, Antonio, Perraut, Karine, Perrin, Guy, Straubmeier, Christian, Kendrew, Sarah, Hippler, Stefan, Brandner, Wolfgang, Clénet, Yann, Deen, Casey, Gendron, Eric, Huber, Armin, Klein, Ralf, Laun, Werner, Lenzen, Rainer, Naranjo, Vianak, Neumann, Udo, Ramos, José, Rohloff, Ralf-Rainer, Yang, Pengqian, Eisenhauer, Frank, Fedrigo, Enrico, Suarez-Valles, Marcos, Amorim, Antonio, Perraut, Karine, Perrin, Guy, and Straubmeier, Christian

Abstract

GRAVITY is a second generation instrument for the VLT Interferometer, designed to enhance the near-infrared astrometric and spectro-imaging capabilities of VLTI. Combining beams from four telescopes, GRAVITY will provide an astrometric precision of order 10 micro-arcseconds, imaging resolution of 4 milli-arcseconds, and low and medium resolution spectro-interferometry, pushing its performance far beyond current infrared interfero- metric capabilities. To maximise the performance of GRAVITY, adaptive optics correction will be implemented at each of the VLT Unit Telescopes to correct for the effects of atmospheric turbulence. To achieve this, the GRAVITY project includes a development programme for four new wavefront sensors (WFS) and NIR-optimized real time control system. These devices will enable closed-loop adaptive correction at the four Unit Telescopes in the range 1.4-2.4 {\mu}m. This is crucially important for an efficient adaptive optics implementation in regions where optically bright references sources are scarce, such as the Galactic Centre. We present here the design of the GRAVITY wavefront sensors and give an overview of the expected adaptive optics performance under typical observing conditions. Benefiting from newly developed SELEX/ESO SAPHIRA electron avalanche photodiode (eAPD) detectors providing fast readout with low noise in the near-infrared, the AO systems are expected to achieve residual wavefront errors of \leq400 nm at an operating frequency of 500 Hz., Comment: to be published in Proc. SPIE vol. 8446 (2012)

Published
2012
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14. Near-infrared wavefront sensing for the VLT interferometer

Author

Hippler, Stefan, Brandner, Wolfgang, Clénet, Yann, Hormuth, Felix, Gendron, Eric, Henning, Thomas, Klein, Ralf, Lenzen, Rainer, Meschke, Daniel, Naranjo, Vianak, Neumann, Udo, Ramos, José Ricardo, Rohloff, Ralf-Rainer, Eisenhauer, Frank, Hippler, Stefan, Brandner, Wolfgang, Clénet, Yann, Hormuth, Felix, Gendron, Eric, Henning, Thomas, Klein, Ralf, Lenzen, Rainer, Meschke, Daniel, Naranjo, Vianak, Neumann, Udo, Ramos, José Ricardo, Rohloff, Ralf-Rainer, and Eisenhauer, Frank

Abstract

The very large telescope (VLT) interferometer (VLTI) in its current operating state is equipped with high-order adaptive optics (MACAO) working in the visible spectrum. A low-order near-infrared wavefront sensor (IRIS) is available to measure non-common path tilt aberrations downstream the high-order deformable mirror. For the next generation of VLTI instrumentation, in particular for the designated GRAVITY instrument, we have examined various designs of a four channel high-order near-infrared wavefront sensor. Particular objectives of our study were the specification of the near-infrared detector in combination with a standard wavefront sensing system. In this paper we present the preliminary design of a Shack-Hartmann wavefront sensor operating in the near-infrared wavelength range, which is capable of measuring the wavefronts of four telescopes simultaneously. We further present results of our design study, which aimed at providing a first instrumental concept for GRAVITY., Comment: 10 pages, 7 figures, to appear in "Ground-based and Airborne Instrumentation for Astronomy II" SPIE conference, Marseille, 23-28 June 2008

Published
2008
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15. Near-infrared wavefront sensing for the VLT interferometer

Author

Hippler, Stefan, Brandner, Wolfgang, Clénet, Yann, Hormuth, Felix, Gendron, Eric, Henning, Thomas, Klein, Ralf, Lenzen, Rainer, Meschke, Daniel, Naranjo, Vianak, Neumann, Udo, Ramos, José Ricardo, Rohloff, Ralf-Rainer, Eisenhauer, Frank, Hippler, Stefan, Brandner, Wolfgang, Clénet, Yann, Hormuth, Felix, Gendron, Eric, Henning, Thomas, Klein, Ralf, Lenzen, Rainer, Meschke, Daniel, Naranjo, Vianak, Neumann, Udo, Ramos, José Ricardo, Rohloff, Ralf-Rainer, and Eisenhauer, Frank

Abstract

The very large telescope (VLT) interferometer (VLTI) in its current operating state is equipped with high-order adaptive optics (MACAO) working in the visible spectrum. A low-order near-infrared wavefront sensor (IRIS) is available to measure non-common path tilt aberrations downstream the high-order deformable mirror. For the next generation of VLTI instrumentation, in particular for the designated GRAVITY instrument, we have examined various designs of a four channel high-order near-infrared wavefront sensor. Particular objectives of our study were the specification of the near-infrared detector in combination with a standard wavefront sensing system. In this paper we present the preliminary design of a Shack-Hartmann wavefront sensor operating in the near-infrared wavelength range, which is capable of measuring the wavefronts of four telescopes simultaneously. We further present results of our design study, which aimed at providing a first instrumental concept for GRAVITY., Comment: 10 pages, 7 figures, to appear in "Ground-based and Airborne Instrumentation for Astronomy II" SPIE conference, Marseille, 23-28 June 2008

Published
2008
Full Text
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