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Your search keyword '"E. M. Gregersen"' showing total 5 results
Start Over Author "E. M. Gregersen" Topic [sdu]sciences of the universe [physics]
5 results on '"E. M. Gregersen"'

1. Odin observations of H2O in the Galactic Centre

Author

E. M. Gregersen, George F. Mitchell, Pierre Encrenaz, P. A. Feldman, Alain Lecacheux, Kalevi Mattila, A. O. H. Olofsson, M. Olberg, Nicholas F. H Tothill, Charles L. Curry, Roy Booth, Urban Frisk, Sun Kwok, B. Larsson, Per Bergman, Kevin Volk, A. Winnberg, M. Lindqvist, Christine D. Wilson, I. Ristorcelli, G. Olofsson, Åke Hjalmarson, M. Fich, R. Plume, Maryvonne Gerin, Fredrik von Schéele, T. Liljeström, Edith Falgarone, John H. Black, Tatsuhiko I. Hasegawa, V. Buat, L. Nordh, René Liseau, H. G. Floren, Jorma Harju, G. Serra, Aa. Sandqvist, L. E. B. Johansson, Laurent Pagani, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique des plasmas, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), and Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Spiral galaxy, Absorption spectroscopy, 010308 nuclear & particles physics, Molecular cloud, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Emission spectrum, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics
Abstract

The Odin satellite has been used to detect emission and absorption in the 557-GHz H2O line in the Galactic Centre towards the Sgr A* Circumnuclear Disk (CND), and the Sgr A +20 km/s and +50 km/s molecular clouds. Strong broad H2O emission lines have been detected in all three objects. Narrow H2O absorption lines are present at all three positions and originate along the lines of sight in the 3-kpc Spiral Arm, the -30 km/s Spiral Arm and the Local Sgr Spiral Arm. Broad H2O absorption lines near -130 km/s are also observed, originating in the Expanding Molecular Ring. A new molecular feature (the ``High Positive Velocity Gas'' - HPVG) has been identified in the positive velocity range of ~ +120 to +220 km/s, seen definitely in absorption against the stronger dust continuum emission from the +20 km/s and +50 km/s clouds and possibly in emission towards the position of Sgr A* CND. The 548-GHz H2_18O isotope line towards the CND is not detected at the 0.02 K (rms) level., 5 pages, 3 figures, accepted by A&A, special Odin Letters issue

Published
2003
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2. First NH3 detection of the Orion Bar

Author

Christine D. Wilson, Åke Hjalmarson, Nicholas F. H Tothill, Alain Lecacheux, Laurent Pagani, Charles L. Curry, B. Larsson, E. M. Gregersen, Veronique Buat, Fredrik von Schéele, John H. Black, George F. Mitchell, Maryvonne Gerin, Kalevi Mattila, Hans G Floren, Aa. Sandqvist, T. Liljeström, Kevin Volk, Göran Olofsson, Roy Booth, Per Bergman, Jorma Harju, L. Nordh, René Liseau, Tatsuhiko I. Hasegawa, Pierre Encrenaz, Lars E B Johansson, Peter F. Bernath, Michel Fich, P. A. Feldman, Rene Plume, Sun Kwok, I. Ristorcelli, Michael Olberg, Urban Frisk, Edith Falgarone, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique des plasmas, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), and Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, 010308 nuclear & particles physics, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Ground state, 010303 astronomy & astrophysics, Source model, Line (formation), Bar (unit)
Abstract

Odin has successfully observed three regions in the Orion A cloud, i.e. Ori KL, Ori S and the Orion Bar, in the 572.5 GHz rotational ground state line of ammonia, ortho-NH3 (J,K) = (1,0) -> (0,0), and the result for the Orion Bar represents the first detection in an ammonia line. Several velocity components are present in the data. Specifically, the observed line profile from the Orion Bar can be decomposed into two components, which are in agreement with observations in high-J CO lines by Wilson et al. 2001. Using the source model for the Orion Bar by these authors, our Odin observation implies a total ammonia abundance of NH3/H2 = 5E-9., 4 pages with 2 figures, accepted for publication in A&A

Published
2003
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3. Submillimeter emission from water in the W3 region

Author

Urban Frisk, A. M. Mason, Jorma Harju, Christine D. Wilson, M. Fich, A. O. H. Olofsson, Åke Hjalmarson, L. Nordh, Per Bergman, René Liseau, Kevin Volk, Aa. Sandqvist, H. G. Floren, Pierre Encrenaz, V. Buat, Rene Plume, Charles L. Curry, Laurent Pagani, E. Falgarone, L. Ristorcelli, Bengt Larsson, Tetsuo Hasegawa, K. Mattila, F. von Schéele, N. Boudet, Sun Kwok, G. Olofsson, G. Serra, Nicholas F. H Tothill, Mika Juvela, P. A. Feldman, Maryvonne Gerin, E. M. Gregersen, Alain Lecacheux, George F. Mitchell, Michael Olberg, Roy Booth, T. Liljeström, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique des plasmas, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), and Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Relative strength, Astrophysics, Absorption (electromagnetic radiation), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Spectral line, Line (formation)
Abstract

We have mapped the submillimeter emission from the 1(10)-1(01) transition of ortho-water in the W3 star-forming region. A 5'x5' map of the W3 IRS4 and W3 IRS5 region reveals strong water lines at half the positions in the map. The relative strength of the Odin lines compared to previous observations by SWAS suggests that we are seeing water emission from an extended region. Across much of the map the lines are double-peaked, with an absorption feature at -39 km/s; however, some positions in the map show a single strong line at -43 km/s. We interpret the double-peaked lines as arising from optically thick, self-absorbed water emission near the W3 IRS5, while the narrower blue-shifted lines originate in emission near W3 IRS4. In this model, the unusual appearance of the spectral lines across the map results from a coincidental agreement in velocity between the emission near W3 IRS4 and the blue peak of the more complex lines near W3 IRS5. The strength of the water lines near W3 IRS4 suggests we may be seeing water emission enhanced in a photon-dominated region., Accepted to A&A Letters as part of the special Odin issue; 4 pages

Published
2003
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4. Odin water mapping in the Orion KL region

Author

John H. Black, G. Serra, Maryvonne Gerin, Michael Olberg, I. Ristorcelli, Bengt Larsson, E. M. Gregersen, Tatsuhiko I. Hasegawa, Aa. Sandqvist, Alain Lecacheux, Edith Falgarone, Pierre Encrenaz, G. Olofsson, Charles L. Curry, M. Fich, Hans Olofsson, H. L. Nordh, Jorma Harju, T. Liljeström, Nicholas F. H Tothill, Urban Frisk, F. von Schéele, L. E. B. Johansson, Åke Hjalmarson, René Liseau, George F. Mitchell, H. G. Floren, Kalevi Mattila, Roy Booth, P. A. Feldman, Sun Kwok, Per Bergman, Christine D. Wilson, Rene Plume, V. Buat, Gustaf Rydbeck, A. O. H. Olofsson, Kevin Volk, Laurent Pagani, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique des plasmas, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), and Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, 010308 nuclear & particles physics, media_common.quotation_subject, Astronomy, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, 7. Clean energy, Asymmetry, Beam size, [SDU]Sciences of the Universe [physics], Space and Planetary Science, 0103 physical sciences, Outflow, Satellite, Halo, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Line (formation), media_common
Abstract

New results from water mapping observations of the Orion KL region using the submm/mm wave satellite Odin (2.1\arcmin beam size at 557 GHz), are presented. The ortho-H2O \jkktrans{1}{1}{0}{1}{0}{1} ground state transition was observed in a 7arcminx 7arcmin rectangular grid with a spacing of 1\arcmin, while the same line of H218O was measured in two positions, Orion KL itself and 2\arcmin south of Orion KL. In the main water species, the KL molecular outflow is largely resolved from the ambient cloud and it is found to have an extension of 60\arcsec-110\arcsec. The H2O outflow profile exhibits a rather striking absorption-like asymmetry at the line centre. Self-absorption in the near (or ``blue'') part of the outflow (and possibly in foreground quiescent halo gas) is tentatively suggested to play a role here. We argue that the dominant part of the KL H218O outflow emission emanates from the compact (size ~ 15\arcsec) low-velocity flow and here estimate an H2O abundance of circa 10-5 compared to all H2 in the flow - an order of magnitude below earlier estimates of the H2O abundance in the shocked gas of the high-velocity flow. The narrow ambient cloud lines show weak velocity trends, both in the N-S and E-W directions. H218O is detected for the first time in the southern position at a level of ~ 0.15 K and we here estimate an H2O abundance of (1-8) x 10-8. Odin is a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes), and the Centre National d'Etudes Spatiales (CNES, France). The Swedish Space Corporation (SSC) was the industrial prime contractor and is also responsible for the satellite operation.

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5. Highlights from the first year of Odin observations

Author

P. A. Feldman, René Liseau, Mathias Fredrixon, Edward J. Llewellyn, George F. Mitchell, L.-Å. Nyman, Hans Olofsson, Cathy Horellou, F. von Schéele, Gustaf Rydbeck, A. O. H. Olofsson, H. G. Floren, Tommy Wiklind, Michael Olberg, Christine D. Wilson, I. Ristorcelli, G. Persson, Roy Booth, Erkki Kyrölä, G. Olofsson, Edith Falgarone, Alain Lecacheux, John H. Black, G. Serra, Michael Lindqvist, Pierre Encrenaz, Nicolas Biver, T. Liljeström, Jorma Harju, Aa. Sandqvist, Sun Kwok, Georg Witt, Anders Winnberg, Rene Plume, Donal P. Murtagh, Magnus Dahlgren, Maryvonne Gerin, Tatsuhiko I. Hasegawa, Peter F. Bernath, L. E. B. Johansson, Urban Frisk, Kalevi Mattila, E. M. Gregersen, Per Bergman, M. Fich, Nicholas F. H Tothill, H. L. Nordh, Åke Hjalmarson, Bengt Larsson, Jacques Crovisier, Laurent Pagani, Steve Torchinsky, G. Mégie, Hans Rickman, V. Buat, Magne Hagström, Charles L. Curry, Kevin Volk, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique des plasmas, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), and Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Mission control center, Chemical models, Comet, Astronomy, Astronomy and Astrophysics, Astrophysics, 7. Clean energy, 01 natural sciences, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, 0103 physical sciences, Satellite, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010306 general physics, 010303 astronomy & astrophysics, Millimetre wave
Abstract

Key Odin operational and instrumental features and highlights from our sub-millimetre and millimetre wave observations of H2O, H218O, NH3, 15NH3 and O2 are presented, with some insights into accompanying Odin Letters in this AA H2O observations of Galactic Centre sources, of shock enhanced H2O towards the SNR IC443, and of the candidate infall source IRAS 16293-2422; H218O detections in Orion KL and in comet Ikeya-Zhang; sub-mm detections of NH3 in Orion KL (outflow, ambient cloud and bar) and ρ Oph, and very recently, of 15NH3 in~Orion KL. Simultaneous sensitive searches for the 119 GHz line of O2 have resulted in very low abundance limits, which are difficult to accomodate in chemical models. We also demonstrate, by means of a quantitative comparison of Orion KL H2O results, that the Odin and SWAS observational data sets are very consistently calibrated. Odin is a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes), and the Centre National d'etudes Spatiales (CNES, France). The Swedish Space Corporation (SSC) has been the prime industrial contractor, and is also responsible for the satellite operation from its Odin Mission Control Centre at SSC in Solna and its Odin Control Centre at ESRANGE near Kiruna in northern Sweden. See also the SNSB Odin web page: http://www.snsb.se/eng_odin_intro.shtml

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