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Author | Poglitsch, A.; Waelkens, C.; Geis, N.; Feuchtgruber, H.; Vandenbussche, B.; Rodriguez, L.; Krause, O.; Renotte, E.; van Hoof, C.; Saraceno, P.; Cepa, J.; Kerschbaum, F.; Agnèse, P.; Ali, B.; Altieri, B.; Andreani, P.; Augueres, J.-L.; Balog, Z.; Barl, L.; Bauer, O. H.; Belbachir, N.; Benedettini, M.; Billot, N.; Boulade, O.; Bischof, H.; Blommaert, J.; Callut, E.; Cara, C.; Cerulli, R.; Cesarsky, D.; Contursi, A.; Creten, Y.; De Meester, W.; Doublier, V.; Doumayrou, E.; Duband, L.; Exter, K.; Genzel, R.; Gillis, J.-M.; Grözinger, U.; Henning, T.; Herreros, J.; Huygen, R.; Inguscio, M.; Jakob, G.; Jamar, C.; Jean, C.; de Jong, J.; Katterloher, R.; Kiss, C.; Klaas, U.; Lemke, D.; Lutz, D.; Madden, S.; Marquet, B.; Martignac, J.; Mazy, A.; Merken, P.; Montfort, F.; Morbidelli, L.; Müller, T.; Nielbock, M.; Okumura, K.; Orfei, R.; Ottensamer, R.; Pezzuto, S.; Popesso, P.; Putzeys, J.; Regibo, S.; Reveret, V.; Royer, P.; Sauvage, M.; Schreiber, J.; Stegmaier, J.; Schmitt, D.; Schubert, J.; Sturm, E.; Thiel, M.; Tofani, G.; Vavrek, R.; Wetzstein, M.; Wieprecht, E.; Wiezorrek, E. | ||||
Title | The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory | Type | Journal Article | ||
Year | 2010 | Publication | Astron. Astrophys. | Abbreviated Journal | A&A |
Volume | 518 | Issue | Pages | 12 | |
Keywords | PACS | ||||
Abstract | The Photodetector Array Camera and Spectrometer (PACS) is one of the three science instruments on ESA's far infrared and submillimetre observatory. It employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16×25 pixels, each, and two filled silicon bolometer arrays with 16×32 and 32×64 pixels, respectively, to perform integral-field spectroscopy and imaging photometry in the 60-210 μm wavelength regime. In photometry mode, it simultaneously images two bands, 60-85 μm or 85-125 μm and 125-210 μm, over a field of view of ~1.75'× 3.5', with close to Nyquist beam sampling in each band. In spectroscopy mode, it images a field of 47â€ × 47â€, resolved into 5×5 pixels, with an instantaneous spectral coverage of ~1500 km s-1 and a spectral resolution of ~175 km s-1. We summarise the design of the instrument, describe observing modes, calibration, and data analysis methods, and present our current assessment of the in-orbit performance of the instrument based on the performance verification tests. PACS is fully operational, and the achieved performance is close to or better than the pre-launch predictions. | ||||
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Call Number | RPLAB @ gujma @ | Serial | 694 | ||
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Author | Griffin, M. J.; Abergel, A.; Abreu, A.; Ade, P. A. R.; André, P.; Augueres, J.-L.; Babbedge, T.; Bae, Y.; Baillie, T.; Baluteau, J.-P.; Barlow, M. J.; Bendo, G.; Benielli, D.; Bock, J. J.; Bonhomme, P.; Brisbin, D.; Brockley-Blatt, C.; Caldwell, M.; Cara, C.; Castro-Rodriguez, N.; Cerulli, R.; Chanial, P.; Chen, S.; Clark, E.; Clements, D. L.; Clerc, L.; Coker, J.; Communal, D.; Conversi, L.; Cox, P.; Crumb, D.; Cunningham, C.; Daly, F.; Davis, G. R.; de Antoni, P.; Delderfield, J.; Devin, N.; di Giorgio, A.; Didschuns, I.; Dohlen, K.; Donati, M.; Dowell, A.; Dowell, C. D.; Duband, L.; Dumaye, L.; Emery, R. J.; Ferlet, M.; Ferrand, D.; Fontignie, J.; Fox, M.; Franceschini, A.; Frerking, M.; Fulton, T.; Garcia, J.; Gastaud, R.; Gear, W. K.; Glenn, J.; Goizel, A.; Griffin, D. K.; Grundy, T.; Guest, S.; Guillemet, L.; Hargrave, P. C.; Harwit, M.; Hastings, P.; Hatziminaoglou, E.; Herman, M.; Hinde, B.; Hristov, V.; Huang, M.; Imhof, P.; Isaak, K. J.; Israelsson, U.; Ivison, R. J.; Jennings, D.; Kiernan, B.; King, K. J.; Lange, A. E.; Latter, W.; Laurent, G.; Laurent, P.; Leeks, S. J.; Lellouch, E.; Levenson, L.; Li, B.; Li, J.; Lilienthal, J.; Lim, T.; Liu, S. J.; Lu, N.; Madden, S.; Mainetti, G.; Marliani, P.; McKay, D.; Mercier, K.; Molinari, S.; Morris, H.; Moseley, H.; Mulder, J.; Mur, M.; Naylor, D. A.; Nguyen, H.; O'Halloran, B.; Oliver, S.; Olofsson, G.; Olofsson, H.-G.; Orfei, R.; Page, M. J.; Pain, I.; Panuzzo, P.; Papageorgiou, A.; Parks, G.; Parr-Burman, P.; Pearce, A.; Pearson, C.; Pérez-Fournon, I.; Pinsard, F.; Pisano, G.; Podosek, J.; Pohlen, M.; Polehampton, E. T.; Pouliquen, D.; Rigopoulou, D.; Rizzo, D.; Roseboom, I. G.; Roussel, H.; Rowan-Robinson, M.; Rownd, B.; Saraceno, P.; Sauvage, M.; Savage, R.; Savini, G.; Sawyer, E.; Scharmberg, C.; Schmitt, D.; Schneider, N.; Schulz, B.; Schwartz, A.; Shafer, R.; Shupe, D. L.; Sibthorpe, B.; Sidher, S.; Smith, A.; Smith, A. J.; Smith, D.; Spencer, L.; Stobie, B.; Sudiwala, R.; Sukhatme, K.; Surace, C.; Stevens, J. A.; Swinyard, B. M.; Trichas, M.; Tourette, T.; Triou, H.; Tseng, S.; Tucker, C.; Turner, A.; Vaccari, M.; Valtchanov, I.; Vigroux, L.; Virique, E.; Voellmer, G.; Walker, H.; Ward, R.; Waskett, T.; Weilert, M.; Wesson, R.; White, G. J.; Whitehouse, N.; Wilson, C. D.; Winter, B.; Woodcraft, A. L.; Wright, G. S.; Xu, C. K.; Zavagno, A.; Zemcov, M.; Zhang, L.; Zonca, E. | ||||
Title | The Herschel-SPIRE instrument and its in-flight performance | Type | Journal Article | ||
Year | 2010 | Publication | Astron. Astrophys. | Abbreviated Journal | A&A |
Volume | 518 | Issue | Pages | 7 | |
Keywords | SPIRE | ||||
Abstract | The Spectral and Photometric Imaging REceiver (SPIRE), is the Herschel Space Observatory`s submillimetre camera and spectrometer. It contains a three-band imaging photometer operating at 250, 350 and 500 μm, and an imaging Fourier-transform spectrometer (FTS) which covers simultaneously its whole operating range of 194-671 μm (447-1550 GHz). The SPIRE detectors are arrays of feedhorn-coupled bolometers cooled to 0.3 K. The photometer has a field of view of 4Â´× 8´, observed simultaneously in the three spectral bands. Its main operating mode is scan-mapping, whereby the field of view is scanned across the sky to achieve full spatial sampling and to cover large areas if desired. The spectrometer has an approximately circular field of view with a diameter of 2.6´. The spectral resolution can be adjusted between 1.2 and 25 GHz by changing the stroke length of the FTS scan mirror. Its main operating mode involves a fixed telescope pointing with multiple scans of the FTS mirror to acquire spectral data. For extended source measurements, multiple position offsets are implemented by means of an internal beam steering mirror to achieve the desired spatial sampling and by rastering of the telescope pointing to map areas larger than the field of view. The SPIRE instrument consists of a cold focal plane unit located inside the Herschel cryostat and warm electronics units, located on the spacecraft Service Module, for instrument control and data handling. Science data are transmitted to Earth with no on-board data compression, and processed by automatic pipelines to produce calibrated science products. The in-flight performance of the instrument matches or exceeds predictions based on pre-launch testing and modelling: the photometer sensitivity is comparable to or slightly better than estimated pre-launch, and the spectrometer sensitivity is also better by a factor of 1.5-2. | ||||
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Call Number | RPLAB @ gujma @ | Serial | 695 | ||
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Author | Pütz, P.; Honingh, C. E.; Jacobs, K.; Justen, M.; Schultz, M.; Stutzki, J. | ||||
Title | Terahertz hot electron bolometer waveguide mixers for GREAT | Type | Journal Article | ||
Year | 2012 | Publication | Astron. Astrophys. | Abbreviated Journal | A&A |
Volume | 542 | Issue | Pages | L2 | |
Keywords | HEB mixer, applications | ||||
Abstract | Context. Supplementing the publications based on the first-light observations with the German REceiver for Astronomy at Terahertz frequencies (GREAT) on SOFIA, we present background information on the underlying heterodyne detector technology. This Letter complements the GREAT instrument Letter and focuses on the mixers itself. Aims. We describe the superconducting hot electron bolometer (HEB) detectors that are used as frequency mixers in the L1 (1400 GHz), L2 (1900 GHz), and M (2500 GHz) channels of GREAT. Measured performance of the detectors is presented and background information on their operation in GREAT is given. Methods. Our mixer units are waveguide-based and couple to free-space radiation via a feedhorn antenna. The HEB mixers are designed, fabricated, characterized, and flight-qualified in-house. We are able to use the full intermediate frequency bandwidth of the mixers using silicon-germanium multi-octave cryogenic low-noise amplifiers with very low input return loss. Results. Superconducting HEB mixers have proven to be practical and sensitive detectors for high-resolution THz frequency spectroscopy on SOFIA. We show that our niobium-titanium-nitride (NbTiN) material HEBs on silicon nitride (SiN) membrane substrates have an intermediate frequency (IF) noise roll-off frequency above 2.8 GHz, which does not limit the current receiver IF bandwidth. Our mixer technology development efforts culminate in the first successful operation of a waveguide-based HEB mixer at 2.5 THz and deployment for radioastronomy. A significant contribution to the success of GREAT is made by technological development, thorough characterization and performance optimization of the mixer and its IF interface for receiver operation on SOFIA. In particular, the development of an optimized mixer IF interface contributes to the low passband ripple and excellent stability, which GREAT demonstrated during its initial successful astronomical observation runs. |
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Call Number | Serial | 907 | |||
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Author | Benz, A. O.; Bruderer, S.; van Dishoeck, E. F.; Stäuber, P.; Wampfler, S. F.; Melchior, M.; Dedes, C.; Wyrowski, F.; Doty, S. D.; van der Tak, F.; Bächtold, W.; Csillaghy, A.; Megej, A.; Monstein, C.; Soldati, M.; Bachiller, R.; Baudry, A.; Benedettini, M.; Bergin, E.; Bjerkeli, P.; Blake, G. A.; Bontemps, S.; Braine, J.; Caselli, P.; Cernicharo, J.; Codella, C.; Daniel, F.; di Giorgio, A. M.; Dieleman, P.; Dominik, C.; Encrenaz, P.; Fich, M.; Fuente, A.; Giannini, T.; Goicoechea, J. R.; de Graauw, Th.; Helmich, F.; Herczeg, G. J.; Herpin, F.; Hogerheijde, M. R.; Jacq, T.; Jellema, W.; Johnstone, D.; Jørgensen, J. K.; Kristensen, L. E.; Larsson, B.; Lis, D.; Liseau, R.; Marseille, M.; McCoey, C.; Melnick, G.; Neufeld, D.; Nisini, B.; Olberg, M.; Ossenkopf, V.; Parise, B.; Pearson, J. C.; Plume, R.; Risacher, C.; Santiago-García, J.; Saraceno, P.; Schieder, R.; Shipman, R.; Stutzki, J.; Tafalla, M.; Tielens, A. G. G. M.; van Kempen, T. A.; Visser, R.; Yıldız, U. A. | ||||
Title | Hydrides in young stellar objects: Radiation tracers in a protostar-disk-outflow system | Type | Journal Article | ||
Year | 2010 | Publication | Astron. Astrophys. | Abbreviated Journal | |
Volume | 521 | Issue | Pages | L35 (1 to 5) | |
Keywords | HEB mixer applications, HIFI, Herschel | ||||
Abstract | Context. Hydrides of the most abundant heavier elements are fundamental molecules in cosmic chemistry. Some of them trace gas irradiated by UV or X-rays. Aims. We explore the abundances of major hydrides in W3 IRS5, a prototypical region of high-mass star formation. Methods. W3 IRS5 was observed by HIFI on the Herschel Space Observatory with deep integration (2500 s) in 8 spectral regions. Results. The target lines including CH, NH, H3O+, and the new molecules SH+, H2O+, and OH+ are detected. The H2O+ and OH+ J = 1–0 lines are found mostly in absorption, but also appear to exhibit weak emission (P-Cyg-like). Emission requires high density, thus originates most likely near the protostar. This is corroborated by the absence of line shifts relative to the young stellar object (YSO). In addition, H2O+ and OH+ also contain strong absorption components at a velocity shifted relative to W3 IRS5, which are attributed to foreground clouds. Conclusions. The molecular column densities derived from observations correlate well with the predictions of a model that assumes the main emission region is in outflow walls, heated and irradiated by protostellar UV radiation. |
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Call Number | Serial | 1082 | |||
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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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Call Number | Serial | 1084 | |||
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