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| 2. |
- Biver, N., et al.
(författare)
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Radio observations of Comet 9P/Tempel 1 before and after Deep Impact
- 2007
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Ingår i: Icarus. - : Elsevier BV. - 1090-2643 .- 0019-1035. ; 191:2, s. 494-512
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Tidskriftsartikel (refereegranskat)abstract
- Comet 9P/Tempel 1 was the target of a multi-wavelength worldwide investigation in 2005. The NASA Deep Impact mission reached the comet on 4.24 July 2005, delivering a 370-kg impactor which hit the comet at 10.3 km s -1 . Following this impact, a cloud of gas and dust was excavated from the comet nucleus. The comet was observed in 2005 prior to and after the impact, at 18-cm wavelength with the Nançay radio telescope, in the millimeter range with the IRAM and CSO radio telescopes, and at 557 GHz with the Odin satellite. OH observations at Nançay provided a 4-month monitoring of the outgassing of the comet from March to June, followed by the observation of H 2 O with Odin from June to August 2005. The peak of outgassing was found to be around 1 × 10 28 molec. s -1 between May and July. Observations conducted with the IRAM 30-m radio telescope in May and July 2005 resulted in detections of HCN, CH 3 OH and H 2 S with classical abundances relative to water (0.12, 2.7 and 0.5%, respectively). In addition, a variation of the HCN production rate with a period of 1.73 ± 0.10 days was observed in May 2005, consistent with the 1.7-day rotation period of the nucleus. The phase of these variations, as well as those of CN seen in July by Jehin et al. [Jehin, E., Manfroid, J., Hutsemékers, D., Cochran, A.L., Arpigny, C., Jackson, W.M., Rauer, H., Schulz, R., Zucconi, J.-M., 2006. Astrophys. J. 641, L145-L148], is consistent with a rotation period of the nucleus of 1.715 days and a strong variation of the outgassing activity by a factor 3 from minimum to maximum. This also implies that the impact took place on the rising phase of the "natural" outgassing which reached its maximum ≈4 h after the impact. Post-impact observations at IRAM and CSO did not reveal a significant change of the outgassing rates and relative abundances, with the exception of CH 3 OH which may have been more abundant by up to one order of magnitude in the ejecta. Most other variations are linked to the intrinsic variability of the comet. The Odin satellite monitored nearly continuously the H 2 O line at 557 GHz during the 38 h following the impact on the 4th of July, in addition to weekly monitoring. Once the periodic variations related to the nucleus rotation are removed, a small increase of outgassing related to the impact is present, which corresponds to the release of ≈ 5000 ± 2000 tons of water. Two other bursts of activity, also observed at other wavelengths, were seen on 23 June and 7 July; they correspond to even larger releases of gas. © 2006 Elsevier Inc. All rights reserved.
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| 3. |
- Biver, N., et al.
(författare)
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Radio observations of Comet 9P/Tempel 1 before and after Deep Impact
- 2007
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Ingår i: Icarus. - : Elsevier BV. - 1090-2643 .- 0019-1035. ; 187:1, s. 253-271
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Tidskriftsartikel (refereegranskat)abstract
- Comet 9P/Tempel 1 was the target of a multi-wavelength worldwide investigation in 2005. The NASA Deep Impact mission reached the comet on 4.24 July 2005, delivering a 370-kg impactor which hit the comet at 10.3 km s -1 . Following this impact, a cloud of gas and dust was excavated from the comet nucleus. The comet was observed in 2005 prior to and after the impact, at 18-cm wavelength with the Nançay radio telescope, in the millimeter range with the IRAM and CSO radio telescopes, and at 557 GHz with the Odin satellite. OH observations at Nançay provided a 4-month monitoring of the outgassing of the comet from March to June, followed by the observation of H 2 O with Odin from June to August 2005. The peak of outgassing was found to be around 1 × 10 28 molec. s -1 between May and July. Observations conducted with the IRAM 30-m radio telescope in May and July 2005 resulted in detections of HCN, CH 3 OH and H 2 S with classical abundances relative to water (0.12, 2.7 and 0.5%, respectively). In addition, a variation of the HCN production rate with a period of 1.73 ± 0.10 days was observed in May 2005, consistent with the 1.7-day rotation period of the nucleus. The phase of these variations, as well as those of CN seen in July by Jehin et al. [Jehin, E., Manfroid, J., Hutsemékers, D., Cochran, A.L., Arpigny, C., Jackson, W.M., Rauer, H., Schulz, R., Zucconi, J.-M., 2006. Astrophys. J. 641, L145-L148], is consistent with a rotation period of the nucleus of 1.715 days and a strong variation of the outgassing activity by a factor 3 from minimum to maximum. This also implies that the impact took place on the rising phase of the "natural" outgassing which reached its maximum ≈4 h after the impact. Post-impact observations at IRAM and CSO did not reveal a significant change of the outgassing rates and relative abundances, with the exception of CH 3 OH which may have been more abundant by up to one order of magnitude in the ejecta. Most other variations are linked to the intrinsic variability of the comet. The Odin satellite monitored nearly continuously the H 2 O line at 557 GHz during the 38 h following the impact on the 4th of July, in addition to weekly monitoring. Once the periodic variations related to the nucleus rotation are removed, a small increase of outgassing related to the impact is present, which corresponds to the release of ≈ 5000 ± 2000 tons of water. Two other bursts of activity, also observed at other wavelengths, were seen on 23 June and 7 July; they correspond to even larger releases of gas. © 2006 Elsevier Inc. All rights reserved.
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| 6. |
- Crovisier, J., et al.
(författare)
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The chemical composition of 9P/tempel 1 from radio observations
- 2009
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Ingår i: ESO Astrophysics Symposia. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1431-2433 .- 1611-6143. - 9783540769583 ; 2009, s. 243-248
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Konferensbidrag (refereegranskat)abstract
- In 2005, as part of a world-wide multi-wavelength investigation of comet 9P/Tempel 1 in support to the Deep Impact mission, we conducted radio spectroscopic observations with the Nançay radio telescope, the Odin satellite, the CSO 10-m and the IRAM 30-m telescopes. We report here our results concerning the chemical composition of the comet. The relative abundances of the detected species (H2O, CH3OH, H2S, HCN) or their upper limits (CO, H2CO, CS) are comparable to the mean values observed in other comets. No significant changes of the outgassing rates (except possibly for CH3OH) or of the molecular abundances were observed following the impact.
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| 10. |
- Frisk, Jessica, et al.
(författare)
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Long-term follow-up of acupuncture and hormone therapy on hot flushes in women with breast cancer: a prospective, randomized, controlled multicenter trial
- 2008
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Ingår i: Climacteric. - : Informa UK Limited. - 1369-7137 .- 1473-0804. ; 11:2, s. 166-174
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To evaluate the effects of electro-acupuncture (EA) and hormone therapy (HT) on vasomotor symptoms in women with a history of breast cancer.Methods: Forty-five women were randomized to EA (n = 27) for 12 weeks or HT (n = 18) for 24 months. The number of and distress caused by hot flushes were registered daily before, during and up to 24 months after start of treatment.Results: In 19 women who completed 12 weeks of EA, the median number of hot flushes/24 h decreased from 9.6 (interquartile range (IQR) 6.6-9.9) at baseline to 4.3 (IQR 1.0-7.1) at 12 weeks of treatment (p < 0.001). At 12 months after start of treatment, 14 women with only the initial 12 weeks of EA had a median number of flushes/24 h of 4.9 (IQR 1.8-7.3), and at 24 months seven women with no other treatment than EA had 2.1 (IQR 1.6-2.8) flushes/24 h. Another five women had a decreased number of flushes after having additional EA. The 18 women with HT had a baseline median number of flushes/24 h of 6.6 (IQR 4.0-8.9), and 0.0 (IQR 0.0-1.6; p = 0.001) at 12 weeks.Conclusion: Electro-acupuncture is a possible treatment of vasomotor symptoms for women with breast cancer and should be further studied for this group of women.
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| 16. |
- Justtanont, Kay, 1965, et al.
(författare)
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W Hya through the Eye of Odin
- 2005
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Ingår i: Astronomy & Astrophysics. ; 439, s. 627-633
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Tidskriftsartikel (refereegranskat)
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| 17. |
- Justtanont, K., et al.
(författare)
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W Hya through the eye of Odin. Satellite observations of circumstellar submillimetre H2O line emission
- 2005
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 439, s. 627-633
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Tidskriftsartikel (refereegranskat)abstract
- We present Odin observations of the AGB star W Hya in the ground-state transition of ortho-H{2}O, 1{10}-101, at 557 GHz. The line is clearly of circumstellar origin. Radiative transfer modelling of the water lines observed by Odin and ISO results in a mass-loss rate of (2.5±0.5)×10-7 Mȯ yr-1, and a circumstellar H{2}O abundance of (2.0±1.0)×10-3. The inferred mass-loss rate is consistent with that obtained from modelling the circumstellar CO radio line emission, and also with that obtained from the dust emission modelling combined with a dynamical model for the outflow. The very high water abundance, higher than the cosmic oxygen abundance, can be explained by invoking an injection of excess water from evaporating icy bodies in the system. The required extra mass of water is quite small, on the order of 0.1 Moplus.
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| 18. |
- Maercker, Matthias, et al.
(författare)
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Circumstellar water vapour in M-type AGB stars: constraints from H2O(1,10-1,01) lines obtained with odin
- 2009
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 494, s. 243-252
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Tidskriftsartikel (refereegranskat)abstract
- Context. A detailed radiative transfer code has been previously used to model circumstellar ortho-H2O line emission towards six M-type asymptotic giant branch stars using Infrared Space Observatory Long Wavelength Spectrometer data. Collisional and radiative excitation, including the v(2) = 1 state, was considered. Aims. Spectrally resolved circumstellar H2O(1(10)-1(01)) lines have been obtained towards three M-type AGB stars using the Odin satellite. This provides additional strong constraints on the properties of circumstellar H2O, in particular on the chemistry in the stellar atmosphere, and the photodissociation in the outer envelope. Methods. Infrared Space Observatory and Odin satellite H2O line data are used as constraints for radiative transfer models. Special consideration is taken to the spectrally resolved Odin line profiles, and the effect of excitation to the first excited vibrational states of the stretching modes (v(1) = 1 and v(3) = 1) on the derived abundances is estimated. A non-local, radiative transfer code based on the accelerated lambda iteration formalism is used. A statistical analysis is performed to determine the best-fit models. Results. The H2O abundance estimates are in agreement with previous estimates. The inclusion of the Odin data sets stronger constraints on the size of the H2O envelope. The H2O(1(10)-1(01)) line profiles require a significant reduction in expansion velocity compared to the terminal gas expansion velocity determined in models of CO radio line emission, indicating that the H2O emission lines probe a region where the wind is still being accelerated. Including the v(3) = 1 state significantly lowers the estimated abundances for the low-mass-loss-rate objects. This shows the importance of detailed modelling, in particular the details of the infrared spectrum in the range 3 to 6 mu m, to estimate accurate circumstellar H2O abundances. Conclusions. Spectrally resolved circumstellar H2O emission lines are important probes of the physics and chemistry in the inner regions of circumstellar envelopes around asymptotic giant branch stars. Predictions for H2O emission lines in the spectral range of the upcoming Herschel/HIFI mission indicate that these observations will be very important in this context.
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| 19. |
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| 20. |
- Olofsson, Henrik, 1972, et al.
(författare)
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A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite. I. The observational data
- 2007
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 476:number 2, December III, s. 791-806
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Tidskriftsartikel (refereegranskat)abstract
- Aims.Spectral line surveys are useful since they allow identification of new molecules and new lines in uniformly calibrated data sets. The subsequent multi-transition analysis will provide improved knowledge of molecular abundances, cloud temperatures and densities, and may also reveal previously unsuspected blends of molecular lines, which otherwise may lead to erroneous conclusions. Nonetheless, large portions of the sub-millimetre spectral regime remain unexplored due to severe absorptions by H2O and O2 in the terrestrial atmosphere. The purpose of the measurements presented here is to cover wavelength regions at and around 0.55 mm - regions largely unobservable from the ground.Methods.Using the Odin astronomy/aeronomy satellite, we performed the first spectral survey of the Orion KL molecular cloud core in the bands 486-492 and 541-576 GHz with rather uniform sensitivity (22-25 mK baseline noise). Odin's 1.1 m size telescope, equipped with four cryo-cooled tuneable mixers connected to broad band spectrometers, was used in a satellite position-switching mode. Two mixers simultaneously observed different 1.1 GHz bands using frequency steps of 0.5 GHz (25 h each). An on-source integration time of 20 h was achieved for most bands. The entire campaign consumed ~1100 orbits, each containing one hour of serviceable astro-observation.Results.We identified 280 spectral lines from 38 known interstellar molecules (including isotopologues) having intensities in the range 80 to 0.05 K. An additional 64 weak lines remain unidentified. Apart from the ground state rotational 11,0-10,1 transitions of ortho-H2O, H218O and H217O, the high energy 62,4-71,7 line of para-H2O (Eu=867$\,$K) and the HDO(20,2-11,1) line have been observed, as well as the 10-01 lines from NH3 and its rare isotopologue 15NH3. We suggest assignments for some unidentified features, notably the new interstellar molecules ND and SH-. Severe blends have been detected in the line wings of the H218O, H217O and 13CO lines changing the true linewidths of the outflow emission.
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| 21. |
- Persson, Carina, 1964, et al.
(författare)
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A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite. II. Data analysis
- 2007
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 476:2, December III, s. 807-827
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Tidskriftsartikel (refereegranskat)abstract
- Aims.We investigate the physical and chemical conditions in a typical star forming region, including an unbiased search for new molecules in a spectral region previously unobserved.Methods.Due to its proximity, the Orion KL region offers a unique laboratory of molecular astrophysics in a chemically rich, massive star forming region. Several ground-based spectral line surveys have been made, but due to the absorption by water and oxygen, the terrestrial atmosphere is completely opaque at frequencies around 487 and 557 GHz. To cover these frequencies we used the Odin satellite to perform a spectral line survey in the frequency ranges 486-492 GHz and 541-577 GHz, filling the gaps between previous spectral scans. Odin's high main beam efficiency, $\eta_{{\rm mb}}$ = 0.9, and observations performed outside the atmosphere make our intensity scale very well determined.Results.We observed 280 spectral lines from 38 molecules including isotopologues, and, in addition, 64 unidentified lines. A few U-lines have interesting frequency coincidences such as ND and the anion SH-. The beam-averaged emission is dominated by CO, H2O, SO2, SO, 13CO and CH3OH. Species with the largest number of lines are CH3OH, (CH3)2O, SO2, 13CH3OH, CH3CN and NO. Six water lines are detected including the ground state rotational transition 11,0-10,1 of o-H2O, its isotopologues o-H218O and o-H217O, the Hot Core tracing p-H2O transition 62,4-71,7, and the 20, 2-11,1 transition of HDO. Other lines of special interest are the 10-0$_$ transition of NH3 and its isotopologue 15NH3. Isotopologue abundance ratios of D/H, 12C/13C, 32S/34S, 34S/33S, and 18O/17O are estimated. The temperatures, column densities and abundances in the various subregions are estimated, and we find very high gas-phase abundances of H2O, NH3, SO2, SO, NO, and CH3OH. A comparison with the ice inventory of ISO sheds new light on the origin of the abundant gas-phase molecules.
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| 22. |
- Ristorcelli, I., et al.
(författare)
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Odin observation of water in the IRAS 16293-2422 low-mass star forming region
- 2005
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Ingår i: Astrochemistry: Recent Successes and Current Challenges. ; , s. 227P-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We present the Odin satellite submillimeter measurement of the ground state transition of ortho-water at 557 GHz around the low-mass protostar IRAS16293-2422. The three following regions have been probed: the on-source position, and the two regions of interaction between the molecular outflows and the dense ambient cloud, i .e. on the SiO peak E1, and near the deuterated peak (cf Lis et al.(2002)). The three spectra reveal broad emission, with a narrow and deep absorption feature at the velocity of the quiescent gas. The water line profiles and intensities have been compared and combined with the CO(3- 2) and HCO+ lines from Lis et al.(2002) after convolution over the Odin beam. The contribution from the central envelope on the water line emission has been estimated with the infall model of Shoier et al. 2002. We show that the water emission is dominated by the outflows, particularly in the red wing of the lines. Using a c-shock modelling (Cabrit et al. 2005), we derive an abundance of X(H2O) 1 - 3 × 10-5 of H2, and shock velocities of 12 - 15 km/s. We also show that the absorption feature is due to the cold outer halo and corresponds to a lower limit of a few 10-9 on the H2O abundance.
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| 24. |
- Urban, Joachim, 1964, et al.
(författare)
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Odin/SMR limb observations of stratospheric trace gases: Validation of N2O
- 2005
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 110:9, s. D09301-20
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Tidskriftsartikel (refereegranskat)abstract
- The Sub-Millimetre Radiometer (Odin/SMR) on board the Odin satellite, launched on 20 February 2001, performs regular measurements of the global distribution of stratospheric nitrous oxide (N2O) using spectral observations of the J = 20&RARR; 19 rotational transition centered at 502.296 GHz. We present a quality assessment for the retrieved N2O profiles (level 2 product) by comparison with independent balloonborne and aircraftborne validation measurements as well as by cross-comparing with preliminary results from other satellite instruments. An agreement with the airborne validation experiments within 28 ppbv in terms of the root mean square (RMS) deviation is found for all SMR data versions (v222, v223, and v1.2) under investigation. More precisely, the agreement is within 19 ppbv for N2O volume mixing ratios (VMR) lower than 200 ppbv and within 10% for mixing ratios larger than 150 ppbv. Given the uncertainties due to atmospheric variability inherent to such comparisons, these values should be interpreted as upper limits for the systematic error of the Odin/SMR N2O measurements. Odin/SMR N2O mixing ratios are systematically slightly higher than nonvalidated data obtained from the Improved Limb Atmospheric Spectrometer-II (ILAS-II) on board the Advanced Earth Observing Satellite-II (ADEOS-II). Root mean square deviations are generally within 23 ppbv (or 20% for VMR-N2O > 100 ppbv) for versions 222 and 223. The comparison with data obtained from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on the Envisat satellite yields a good agreement within 9-17 ppbv (or 10% for VMR-N2O > 100 ppbv) for the same data versions. Odin/SMR version 1.2 data show somewhat larger RMS deviations and a higher positive bias.
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| 25. |
- Wang, D.Y., et al.
(författare)
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Comparisons of MIPAS/ENVISAT ozone profiles with SMR/ODIN and HALOE/UARS observations
- 2005
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Ingår i: Advances in Space Research. - : Elsevier BV. - 1879-1948 .- 0273-1177. ; 36:5, s. 927-931
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Tidskriftsartikel (refereegranskat)abstract
- Ozone volume mixing ratio (VMR) profiles are measured by the Michelson Interferometer for passive atmospheric sounding (MIPAS) on ENVISAT. The data sets produced by the science data processor at Institut fur Meteorologic und Klimaforschung (IMK), Germany are compared with those obtained by halogen occultation experiment (HALOE) on UARS and by sub-millimetre radiometer (SMR) on ODIN. For the stratospheric measurements taken during September/October 2002, the three instruments show reasonable agreement, with global mean differences within 0.1-0.3 ppmv. The typical zonal mean differences are of 0.4 ppmv for HALOE and 0.6 ppmv for SMR (4-6%) in the ozone VMR peak region at 25-30 km near the equator, though larger differences of 0.8-1 ppmv (8-10%) are also observed in a small latitude-altitude region in the tropic. A positive bias of about 0.2-0.4 ppmv in the MIPAS data in the 35-40 km region has also been found. Further studies are under way to explain these differences.
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