|
Records |
Links |
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Wampfler, S. F.; Herczeg, G. J.; Bruderer, S.; Benz, A. O.; van Dishoeck, E. F.; Kristensen, L. E.; Visser, R.; Doty, S. D.; Melchior, M.; van Kempen, T. A.; Yıldız, U. A.; Dedes, C.; Goicoechea, J. R.; Baudry, A.; Melnick, G.; Bachiller, R.; 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.; Dominik, C.; Encrenaz, P.; Fich, M.; Fuente, A.; Giannini, T.; de Graauw, Th.; Helmich, F.; Herpin, F.; Hogerheijde, M. R.; Jacq, T.; Johnstone, D.; Jørgensen, J. K.; Larsson, B.; Lis, D.; Liseau, R.; Marseille, M.; Mc Coey, C.; Neufeld, D.; Nisini, B.; Olberg, M.; Parise, B.; Pearson, J. C.; Plume, R.; Risacher, C.; Santiago-García, J.; Saraceno, P.; Shipman, R.; Tafalla, M.; van der Tak, F. F. S.; Wyrowski, F.; Roelfsema, P.; Jellema, W.; Dieleman, P.; Caux, E.; Stutzki, J. |
![find record details (via OpenURL) openurl](img/xref.gif)
|
|
Title |
Herschel observations of the hydroxyl radical (OH) in young stellar objects |
Type |
Journal Article |
|
Year |
2010 |
Publication |
Astron. Astrophys. |
Abbreviated Journal |
|
|
|
Volume |
521 |
Issue |
|
Pages |
L36 |
|
|
Keywords |
HEB mixer applications, HIFI, Herschel, astrochemistry / stars: formation / ISM: molecules / ISM: jets and outflows / ISM: individual objects: HH 46 |
|
|
Abstract |
Aims. “Water In Star-forming regions with Herschel†(WISH) is a Herschel key program investigating the water chemistry in young stellar objects (YSOs) during protostellar evolution. Hydroxyl (OH) is one of the reactants in the chemical network most closely linked to the formation and destruction of H2O. High-temperature (T 250 K) chemistry connects OH and H2O through the OH + H2 H2O + H reactions. Formation of H2O from OH is efficient in the high-temperature regime found in shocks and the innermost part of protostellar envelopes. Moreover, in the presence of UV photons, OH can be produced from the photo-dissociation of H2O through H2O + γUV OH + H.
Methods. High-resolution spectroscopy of the 163.12 μm triplet of OH towards HH 46 and NGC 1333 IRAS 2A was carried out with the Heterodyne Instrument for the Far Infrared (HIFI) on board the Herschel Space Observatory. The low- and intermediate-mass protostars HH 46, TMR 1, IRAS 15398-3359, DK Cha, NGC 7129 FIRS 2, and NGC 1333 IRAS 2A were observed with the Photodetector Array Camera and Spectrometer (PACS) on Herschel in four transitions of OH and two [O i] lines.
Results. The OH transitions at 79, 84, 119, and 163 μm and [O i] emission at 63 and 145μm were detected with PACS towards the class I low-mass YSOs as well as the intermediate-mass and class I Herbig Ae sources. No OH emission was detected from the class 0 YSO NGC 1333 IRAS 2A, though the 119 μm was detected in absorption. With HIFI, the 163.12 μm was not detected from HH 46 and only tentatively detected from NGC 1333 IRAS 2A. The combination of the PACS and HIFI results for HH 46 constrains the line width (FWHM 11 km s-1) and indicates that the OH emission likely originates from shocked gas. This scenario is supported by trends of the OH flux increasing with the [O i] flux and the bolometric luminosity, as found in our sample. Similar OH line ratios for most sources suggest that OH has comparable excitation temperatures despite the different physical properties of the sources. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
|
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
|
Serial |
1103 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Wei, Jian; Olaya, David; Karasik, Boris S.; Pereverzev, Sergey V.; Sergeev, Andrei V.; Gershenson, Michael E. |
![goto web page (via DOI) doi](img/doi.gif)
|
|
Title |
Ultrasensitive hot-electron nanobolometers for terahertz astrophysics |
Type |
Journal Article |
|
Year |
2008 |
Publication |
Nature Nanotechnology |
Abbreviated Journal |
Nature Nanotech |
|
|
Volume |
3 |
Issue |
8 |
Pages |
496-500 |
|
|
Keywords |
HEB, Ti/NbN, single terahertz photons, detection |
|
|
Abstract |
The submillimetre or terahertz region of the electromagnetic spectrum contains approximately half of the total luminosity of the Universe and 98% of all the photons emitted since the Big Bang. This radiation is strongly absorbed in the Earth's atmosphere, so space-based terahertz telescopes are crucial for exploring the evolution of the Universe. Thermal emission from the primary mirrors in these telescopes can be reduced below the level of the cosmic background by active cooling, which expands the range of faint objects that can be observed. However, it will also be necessary to develop bolometers – devices for measuring the energy of electromagnetic radiation—with sensitivities that are at least two orders of magnitude better than the present state of the art. To achieve this sensitivity without sacrificing operating speed, two conditions are required. First, the bolometer should be exceptionally well thermally isolated from the environment;
second, its heat capacity should be sufficiently small. Here we demonstrate that these goals can be achieved by building a superconducting hot-electron nanobolometer. Its design eliminates the energy exchange between hot electrons and the leads by blocking electron outdiffusion and photon emission. The thermal conductance between hot electrons and the thermal bath, controlled by electron–phonon interactions, becomes very small at low temperatures (10-16 WK-1 at 40 mK). These devices, with a heat capacity of 10-19 J K-1, are sufficiently sensitive to detect single terahertz photons in submillimetre astronomy and other applications based on quantum calorimetry and photon counting. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1748-3387 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
|
Serial |
576 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Yagoubov, P.; Gol'tsman, G.; Voronov, B.; Svechnikov, S.; Cherednichenko, S.; Gershenzon, E.; Belitsky, V.; Ekström, H.; Semenov, A.; Gousev, Yu.; Renk, K. |
![find record details (via OpenURL) openurl](img/xref.gif)
|
|
Title |
Quasioptical phonon-cooled NbN hot-electron bolometer mixer at THz frequencies |
Type |
Conference Article |
|
Year |
1996 |
Publication |
Proc. 7th Int. Symp. Space Terahertz Technol. |
Abbreviated Journal |
Proc. 7th Int. Symp. Space Terahertz Technol. |
|
|
Volume |
|
Issue |
|
Pages |
303-317 |
|
|
Keywords |
NbN HEB mixers |
|
|
Abstract |
In our experiments we tested phonon-cooled hot-electron bolometer (HEB) quasioptical mixer based on spiral antenna designed for 0.5-1.2 THz frequency band and fabricated on sapphire, Si-coated sapphire and high resistivity silicon substrates. HEB devices were produced from thin superconducting NbN film 3.5-6 nm thick with the critical temperature of about 11-12 K. For these devices we achieved the receiver noise temperature T R (DSB) = 3000 K in the 500-700 GHz frequency range and an IF bandwidth of 3-4 GHz. Prelimanary measurements at frequencies 1-1.2 THz resulted the receiver noise temperature about 9000 K (DSB). |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
|
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
|
Serial |
1614 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Yagoubov, P.; Hübers, H.-W.; Gol’tsman, G.; Semenov, A.; Gao, J.; Hoogeveen, R.; de Graauw, T.; Birk, M.; Selig, A.; de Korte, P. |
![find book details (via ISBN) isbn](img/isbn.gif)
|
|
Title |
Hot-electron bolometer mixers – technology for far-infrared heterodyne instruments in future atmospheric chemistry missions |
Type |
Conference Article |
|
Year |
2001 |
Publication |
Proc. 3rd Int. Symp. Submillimeter Wave Earth Observation From Space |
Abbreviated Journal |
Proc. 3rd Int. Symp. Submillimeter Wave Earth Observation From Space |
|
|
Volume |
|
Issue |
|
Pages |
57-69 |
|
|
Keywords |
HEB mixers |
|
|
Abstract |
|
|
|
Address |
Delmenhorst |
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
Logos-Verlag |
Place of Publication |
|
Editor |
Buehler, S.; Berlin |
|
|
Language |
|
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
|
ISBN |
3-89722-700-2 |
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
International Symposium on Submillimeter Wave Earth Observation from Space, ISSMWEOS01 |
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
|
Serial |
1549 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Yagoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Gol'tsman, G.; Svechnikov, S.; Gershenzon, E. |
![goto web page (via DOI) doi](img/doi.gif)
|
|
Title |
Noise temperature and local oscillator power requirement of NbN phonon-cooled hot electron bolometric mixers at terahertz frequencies |
Type |
Journal Article |
|
Year |
1998 |
Publication |
Appl. Phys. Lett. |
Abbreviated Journal |
Appl. Phys. Lett. |
|
|
Volume |
73 |
Issue |
19 |
Pages |
2814-2816 |
|
|
Keywords |
NbN HEB mixers, noise temperature, local oscillator power |
|
|
Abstract |
In this letter, the noise performance of NbN-based phonon-cooled hot electron bolometric quasioptical mixers is investigated in the 0.55–1.1 THz frequency range. The best results of the double-sideband <cd><2018>DSB<cd><2019> noise temperature are: 500 K at 640 GHz, 600 K at 750 GHz, 850 K at 910 GHz, and 1250 K at 1.1 THz. The water vapor in the signal path causes significant contribution to the measured receiver noise temperature around 1.1 THz. The devices are made from 3-nm-thick NbN film on high-resistivity Si and integrated with a planar spiral antenna on the same substrate. The in-plane dimensions of the bolometer strip are typically 0.2Ï«2 um. The amount of local oscillator power absorbed in the bolometer is less than 100 nW. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
|
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
|
Serial |
911 |
|
Permanent link to this record |