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| Author | Bujarrabal, V.; Alcolea, J.; Soria-Ruiz, R.; Planesas, P.; Teyssier, D.; Marston, A. P.; Cernicharo, J.; Decin, L.; Dominik, C.; Justtanont, K.; de Koter, A.; Melnick, G.; Menten, K. M.; Neufeld, D. A.; Olofsson, H.; Schmidt, M.; Schöier, F. L.; Szczerba, R.; Waters, L. B. F. M.; Quintana-Lacaci, G.; Güsten, R.; Gallego, J. D.; Díez-González, M. C.; Barcia, A.; López-Fernández, I.; Wildeman, K.; Tielens, A. G. G. M.; Jacobs, K. | ||||
| Title | Herschel/HIFI observations of high-J CO transitions in the protoplanetary nebula CRL 618 | Type | Journal Article | ||
| Year | 2010 | Publication | Astron. Astrophys. | Abbreviated Journal | |
| Volume | 521 | Issue | Pages | L3 (1 to 5) | |
| Keywords | HEB mixer applications, HIFI, Herschel | ||||
| Abstract | Aims. We aim to study the physical conditions, particularly the excitation state, of the intermediate-temperature gas components in the protoplanetary nebula CRL 618. These components are particularly important for understanding the evolution of the nebula. Methods. We performed Herschel/HIFI observations of several CO lines in the far-infrared/sub-mm in the protoplanetary nebula CRL 618. The high spectral resolution provided by HIFI allows measurement of the line profiles. Since the dynamics and structure of the nebula is well known from mm-wave interferometric maps, it is possible to identify the contributions of the different nebular components (fast bipolar outflows, double shells, compact slow shell) to the line profiles. The observation of these relatively high-energy transitions allows an accurate study of the excitation conditions in these components, particularly in the warm ones, which cannot be properly studied from the low-energy lines. Results. The 12CO J = 16–15, 10–9, and 6–5 lines are easily detected in this source. Both 13CO J = 10–9 and 6–5 are also detected. Wide profiles showing spectacular line wings have been found, particularly in 12CO J = 16–15. Other lines observed simultaneously with CO are also shown. Our analysis of the CO high-J transitions, when compared with the existing models, confirms the very low expansion velocity of the central, dense component, which probably indicates that the shells ejected during the last AGB phases were driven by radiation pressure under a regime of maximum transfer of momentum. No contribution of the diffuse halo found from mm-wave data is identified in our spectra, because of its low temperature. We find that the fast bipolar outflow is quite hot, much hotter than previously estimated; for instance, gas flowing at 100 km s-1 must have a temperature higher than ~200 K. Probably, this very fast outflow, with a kinematic age <100 yr, has been accelerated by a shock and has not yet cooled down. The double empty shell found from mm-wave mapping must also be relatively hot, in agreement with the previous estimate. |
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| Notes | Approved | no | |||
| Call Number | Serial | 1084 | |||
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| Author | Hartogh, P.; Crovisier, J.; de Val-Borro, M.; Bockelée-Morvan, D.; Biver, N.; Lis, D. C.; Moreno, R.; Jarchow, C.; Rengel, M.; Emprechtinger, M.; Szutowicz, S.; Banaszkiewicz, M.; Bensch, F.; Blecka, M. I.; Cavalié, T.; Encrenaz, T.; Jehin, E.; Küppers, M.; Lara, L.-M.; Lellouch, E.; Swinyard, B. M.; Vandenbussche, B.; Bergin, E. A.; Blake, G. A.; Blommaert, J. A. D. L.; Cernicharo, J.; Decin, L.; Encrenaz, P.; de Graauw, T.; Hutsemekers, D.; Kidger, M.; Manfroid, J.; Medvedev, A. S.; Naylor, D. A.; Schieder, R.; Thomas, N.; Waelkens, C.; Roelfsema, P. R.; Dieleman, P.; Güsten, R.; Klein, T.; Kasemann, C.; Caris, M.; Olberg, M.; Benz, A. O. | ||||
| Title | HIFI observations of water in the atmosphere of comet C/2008 Q3 (Garradd) | Type | Journal Article | ||
| Year | 2010 | Publication | Astron. Astrophys. | Abbreviated Journal | |
| Volume | 518 | Issue | Pages | L150 (1 to 5) | |
| Keywords | HEB mixer applications, HIFI, Herschel, comets: individual: C/2008 Q3 / radio lines: general / submillimeter: general / techniques: spectroscopic | ||||
| Abstract | High-resolution far-infrared and sub-millimetre spectroscopy of water lines is an important tool to understand the physical and chemical properties of cometary atmospheres. We present observations of several rotational ortho- and para-water transitions in comet C/2008 Q3 (Garradd) performed with HIFI on Herschel. These observations have provided the first detection of the 212–101 (1669 GHz) ortho and 111–000 (1113 GHz) para transitions of water in a cometary spectrum. In addition, the ground-state transition 110–101 at 557 GHz is detected and mapped. By detecting several water lines quasi-simultaneously and mapping their emission we can constrain the excitation parameters in the coma. Synthetic line profiles are computed using excitation models which include excitation by collisions, solar infrared radiation, and radiation trapping. We obtain the gas kinetic temperature, constrain the electron density profile, and estimate the coma expansion velocity by analyzing the map and line shapes. We derive water production rates of 1.7–2.8 × 1028 s-1 over the range rh = 1.83–1.85 AU. | ||||
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| Call Number | Serial | 1088 | |||
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| Author | Sahu, Mitrabhanu; Bae, Myung-Ho; Rogachev, Andrey; Pekker, David; Wei, Tzu-Chieh; Shah, Nayana; Goldbart, Paul M.; Bezryadin, Alexey | ||||
| Title | Individual topological tunnelling events of a quantum field probed through their macroscopic consequences | Type | Journal Article | ||
| Year | 2009 | Publication | Nature Phys. | Abbreviated Journal | Nature Phys. |
| Volume | 5 | Issue | Pages | 503-508 | |
| Keywords | phase slips, superconducting nanowires | ||||
| Abstract | Phase slips are topological fluctuations that carry the superconducting order-parameter field between distinct current-carrying states. Owing to these phase slips, superconducting nanowires acquire electrical resistance. In such wires, it is well known that at higher temperatures phase slips occur through the process of thermal barrier-crossing by the order-parameter field. At low temperatures, the general expectation is that phase slips should proceed through quantum tunnelling events, which are known as quantum phase slips. However, resistive measurements have produced evidence both for and against the occurrence of quantum phase slips. Here, we report evidence for the observation of individual quantum phase-slip events in homogeneous ultranarrow wires at high bias currents. We accomplish this through measurements of the distribution of switching currents for which the width exhibits a rather counter-intuitive, monotonic increase with decreasing temperature. Importantly, measurements show that in nanowires with larger critical currents, quantum fluctuations dominate thermal fluctuations up to higher temperatures. | ||||
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| Notes | Recommended by Klapwijk | Approved | no | ||
| Call Number | Serial | 928 | |||
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| Author | Thijs de Graauw; Nick Whyborn; Frank Helmich; Pieter Dieleman; Peter Roelfsema; Emmanuel Caux; Tom Phillips; Jürgen Stutzki; Douwe Beintema; Arnold Benz; Nicolas Biver; Adwin Boogert; Francois Boulanger; Sergey Cherednichenko; Odile Coeur-Joly; Claudia Comito; Emmanuel Dartois; Albrecht de Jonge; Gert de Lange; Ian Delorme; Anna DiGiorgio; Luc Dubbeldam; Kevin Edwards; Michael Fich; Rolf Güsten; Fabrice Herpin; Netty Honingh; Robert Huisman; Herman Jacobs; Willem Jellema; Jon Kawamura; Do Kester; Teun Klapwijk; Thomas Klein; Jacob Kooi; Jean-Michel Krieg; Carsten Kramer; Bob Kruizenga; Wouter Laauwen; Bengt Larsson; Christian Leinz; Rene Liseau; Steve Lord; Willem Luinge; Anthony Marston; Harald Merkel; Rafael Moreno; Patrick Morris; Anthony Murphy; Albert Naber; Pere Planesas; Jesus Martin-Pintado; Micheal Olberg; Piotr Orleanski; Volker Ossenkopf; John Pearson; Michel Perault; Sabine Phillip; Mirek Rataj; Laurent Ravera; Paolo Saraceno; Rudolf Schieder; Frank Schmuelling; Ryszard Szczerba; Russell Shipman; David Teyssier; Charlotte Vastel; Huib Visser; Klaas Wildeman; Kees Wafelbakker; John Ward; Roonan Higgins; Henri Aarts; Xander Tielens; Peer Zaal | ||||
| Title | The Herschel-heterodyne instrument for the far-infrared (HIFI): instrument and pre-launch testing | Type | Conference Article | ||
| Year | 2008 | Publication | Proc. SPIE | Abbreviated Journal | |
| Volume | 7010 | Issue | Pages | 701004 | |
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| Call Number | Serial | 422 | |||
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| Author | Mair, U.; Suttywong, N.; Hübers, H.-W.; Semenov, A. D.; Richter, H.; Wagner, G.; Birk, M. | ||||
| Title | Development of 1.8 THz receiver for the TELIS instrument | Type | Conference Article | ||
| Year | 2005 | Publication | Proc. 16th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | |
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| Publisher | Place of Publication | Göteborg, Sweden | Editor | ||
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| Call Number | RPLAB @ s @ qo_TELIS_1p8_THz | Serial | 364 | ||
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