References of "Blecka, M. I"
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See detailHIFI observations of water in the atmosphere of comet C/2008 Q3 (Garradd)
Hartogh, P.; Crovisier, J.; de Val-Borro, M. et al

in Astronomy and Astrophysics (2010), 518(Letters), 1501-5

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 ... [more ▼]

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 2[SUB]12[/SUB]-1[SUB]01[/SUB] (1669 GHz) ortho and 1[SUB]11[/SUB]-0[SUB]00[/SUB] (1113 GHz) para transitions of water in a cometary spectrum. In addition, the ground-state transition 1[SUB]10[/SUB]-1[SUB]01[/SUB] 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 × 10[SUP]28[/SUP] s[SUP]-1[/SUP] over the range r[SUB]h[/SUB] = 1.83-1.85 AU. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Figure 5 is only available in electronic form at <A href="http://www.aanda.org">http://www.aanda.org</A> [less ▲]

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See detailA study of the distant activity of comet C/2006 W3 (Christensen) with Herschel and ground-based radio telescopes
Bockelée-Morvan, D.; Hartogh, P.; Crovisier, J. et al

in Astronomy and Astrophysics (2010), 518(Letters), 1491-6

Comet C/2006 W3 (Christensen) was observed in November 2009 at 3.3 AU from the Sun with Herschel.The PACS instrument acquired images of the dust coma in 70-μm and 160-μm filters and spectra covering ... [more ▼]

Comet C/2006 W3 (Christensen) was observed in November 2009 at 3.3 AU from the Sun with Herschel.The PACS instrument acquired images of the dust coma in 70-μm and 160-μm filters and spectra covering several H[SUB]2[/SUB]O rotational lines. Spectra in the range 450-1550 GHz were acquired with SPIRE. The comet emission continuum from 70 to 672 μm was measured, but no lines were detected. The spectral energy distribution indicates thermal emission from large particles and provides a measure of the size distribution index and dust production rate. The upper limit to the water production rate is compared to the production rates of other species (CO, CH[SUB]3[/SUB]OH, HCN, H[SUB]2[/SUB]S, OH) measured with the IRAM 30-m and Nançay telescopes. The coma is found to be strongly enriched in species more volatile than water, in comparison to comets observed closer to the Sun. The CO to H[SUB]2[/SUB]O production rate ratio exceeds 220%. The dust-to-gas production rate ratio is on the order of 1. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Figures 2, 5, 6 are only available in electronic form at <A href="http://www.aanda.org">http://www.aanda.org</A> [less ▲]

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See detailFirst results of Herschel-PACS observations of Neptune
Lellouch, E.; Hartogh, P.; Feuchtgruber, H. et al

in Astronomy and Astrophysics (2010), 518

We report on the initial analysis of a Herschel-PACS full range spectrum of Neptune, covering the 51-220 μm range with a mean resolving power of ~3000, and complemented by a dedicated observation of CH ... [more ▼]

We report on the initial analysis of a Herschel-PACS full range spectrum of Neptune, covering the 51-220 μm range with a mean resolving power of ~3000, and complemented by a dedicated observation of CH[SUB]4[/SUB] at 120 μm. Numerous spectral features due to HD (R(0) and R(1)), H[SUB]2[/SUB]O, CH[SUB]4[/SUB], and CO are present, but so far no new species have been found. Our results indicate that (i) Neptune's mean thermal profile is warmer by ~3 K than inferred from the Voyager radio-occultation; (ii) the D/H mixing ratio is (4.5 ± 1) × 10[SUP]-5[/SUP], confirming the enrichment of Neptune in deuterium over the protosolar value (~2.1 × 10[SUP]-5[/SUP]); (iii) the CH[SUB]4[/SUB] mixing ratio in the mid stratosphere is (1.5 ± 0.2) × 10[SUP]-3[/SUP], and CH[SUB]4[/SUB] appears to decrease in the lower stratosphere at a rate consistent with local saturation, in agreement with the scenario of CH[SUB]4[/SUB] stratospheric injection from Neptune's warm south polar region; (iv) the H[SUB]2[/SUB]O stratospheric column is (2.1 ± 0.5) × 10[SUP]14[/SUP] cm[SUP]-2[/SUP] but its vertical distribution is still to be determined, so the H[SUB]2[/SUB]O external flux remains uncertain by over an order of magnitude; and (v) the CO stratospheric abundance is about twice the tropospheric value, confirming the dual origin of CO suspected from ground-based millimeter/submillimeter observations. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. [less ▲]

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See detailWater and related chemistry in the solar system. A guaranteed time key programme for Herschel
Hartogh, P.; Lellouch, E.; Crovisier, J. et al

in Planetary and Space Science (2009), 57

â Water and related chemistry in the Solar Systemâ is a Herschel Space Observatory Guaranteed-Time Key Programme. This project, approved by the European Space Agency, aims at determining the distribution ... [more ▼]

â Water and related chemistry in the Solar Systemâ is a Herschel Space Observatory Guaranteed-Time Key Programme. This project, approved by the European Space Agency, aims at determining the distribution, the evolution and the origin of water in Mars, the outer planets, Titan, Enceladus and the comets. It addresses the broad topic of water and its isotopologues in planetary and cometary atmospheres. The nature of cometary activity and the thermodynamics of cometary comae will be investigated by studying water excitation in a sample of comets. The D/H ratio, the key parameter for constraining the origin and evolution of Solar System species, will be measured for the first time in a Jupiter-family comet. A comparison with existing and new measurements of D/H in Oort-cloud comets will constrain the composition of pre-solar cometary grains and possibly the dynamics of the protosolar nebula. New measurements of D/H in giant planets, similarly constraining the composition of proto-planetary ices, will be obtained. The D/H and other isotopic ratios, diagnostic of Marsâ atmosphere evolution, will be accurately measured in H[SUB]2[/SUB]O and CO. The role of water vapor in Marsâ atmospheric chemistry will be studied by monitoring vertical profiles of H[SUB]2[/SUB]O and HDO and by searching for several other species (and CO and H[SUB]2[/SUB]O isotopes). A detailed study of the source of water in the upper atmosphere of the Giant Planets and Titan will be performed. By monitoring the water abundance, vertical profile, and input fluxes in the various objects, and when possible with the help of mapping observations, we will discriminate between the possible sources of water in the outer planets (interplanetary dust particles, cometary impacts, and local sources). In addition to these inter-connected objectives, serendipitous searches will enhance our knowledge of the composition of planetary and cometary atmospheres. [less ▲]

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