References of "Jehin, Emmanuel"
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See detailWater and related chemistry in the Solar System. A Guaranteed Time Key Programme for Herschel
Hartogh, P.; Crovisier, J.; Lellouch, E. et al

in EPSC Abstracts 2009 (2009)

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See detailESO Spectrophotometry of Comet 9P/Tempel 1
Weiler, M.; Rauer, H.; Sterken, C. et al

in Käufl, H. U.; Sterken, C. (Eds.) Deep Impact as a World Observatory Event: Synergies in Space, Time, and Wavelength (2009)

The Deep Impact target comet 9P/Tempel 1 was observed by means of long-slit spectroscopy from two nights before impact up to eight nights after impact, using the ESO VLT UT1, UT2, and ESO NTT telescopes ... [more ▼]

The Deep Impact target comet 9P/Tempel 1 was observed by means of long-slit spectroscopy from two nights before impact up to eight nights after impact, using the ESO VLT UT1, UT2, and ESO NTT telescopes. Spectra covering the complete optical wavelength range were obtained, and information at different position angles in the coma was collected. The data were used to study the gas and dust activity of comet 9P/Tempel 1. Gas production rates before and after impact and the amount of material in the impact cloud were determined. The pre-impact Afρ parameter, the dust production rate and the dust-to-gas mass ratio were derived. A variation of the cometary gas activity with rotation of the nucleus was detected. A difference in the variation of the brightness of the CN gas emission band compared to the variation of the emissions by C_2, C_3, and NH_2 in the inner coma suggests compositional differences between different parts of the surface of comet 9P/Tempel 1's nucleus. [less ▲]

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See detailDynamical Modeling of the Deep Impact Dust Ejecta Cloud
Bonev, T.; Ageorges, N.; Bagnulo, S. et al

in Käufl, H. U.; Sterken, C. (Eds.) Deep Impact as a World Observatory Event: Synergies in Space, Time, and Wavelength (2009)

The collision of Deep Impact with comet 9P/Tempel 1 generated a bright cloud of dust which dissipated during several days after the impact. The brightness variations of this cloud and the changes of its ... [more ▼]

The collision of Deep Impact with comet 9P/Tempel 1 generated a bright cloud of dust which dissipated during several days after the impact. The brightness variations of this cloud and the changes of its position and shape are governed by the physical properties of the dust grains. We use a Monte Carlo model to describe the evolution of the post-impact dust plume. The results of our dynamical simulations are compared to the data obtained with FORS2footnote{FORS stands for \underline{FO}cal Reducer and low dispersion Spectrograph for the Very Large Telescope (VLT) of the European Southern Observatory (ESO).} to derive the particle size distribution and the total amount of material contained in the dust ejecta cloud. [less ▲]

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See detailThe Dusty View of DI from ESO Chile
Boehnhardt, H.; Ageorges, N.; Bagnulo, S. et al

in Käufk, H. U.; Sterken, C. (Eds.) Deep Impact as a World Observatory Event: Synergies in Space, Time, and Wavelength (2009)

Around the time of the impact of NASA's Deep Impact (DI) mission at comet 9P/Tempel 1, in total 6 telescopes with altogether 7 different instruments, located at the La Silla (LSO) and Paranal (VLT ... [more ▼]

Around the time of the impact of NASA's Deep Impact (DI) mission at comet 9P/Tempel 1, in total 6 telescopes with altogether 7 different instruments, located at the La Silla (LSO) and Paranal (VLT) Observatories of the European Southern Observatory (ESO) in Chile, were used to characterize the dust properties before and after the event. The ejecta cloud expanded at an average speed of about 200 ms[SUP]-1[/SUP]during the first hours after the event. It reached stagnation distance of 25000 km about 3 days after impact. The pre-impact dust jet and fan activity (`porcupine' pattern) remained undisturbed after impact. In our measurements the jet activity can be traced to a few 100 km nucleus distance. In total 9 comastructures are identified which may originate from at least 4 regions of enhanced dust emission on the nucleus - one of this region may in fact be multiple. No obvious signatures of a new active region created by DI are found. The overall dust production during the impact compares to about 5-10 h of normal activity. The global expansion geometry of the DI cloud is compatible with a majority of dust grains in the micron size range. Indications exist for asymmetric brightness and colour distributions of the dust in the ejecta cloud. The dust temperature rose from about 280-290 K before to 330 K one day after the event and fell to pre-impact level the day thereafter. The dust reflected sunlight was found to be linearly polarized at about 7.5% in the visible and near-IR, at constant level within about 4000 km from the nucleus. No circular polarization of the dust is detected. [less ▲]

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See detailThe 16OH/18OH and OD/OH isotope ratios in comet C/2002 T7 (LINEAR)
Hutsemekers, Damien ULg; Manfroid, Jean ULg; Jehin, Emmanuel ULg et al

in Astronomy and Astrophysics (2008), 490(Letters), 31-34

The [SUP]16[/SUP]OH/[SUP]18[/SUP]OH and OD/OH isotope ratios are measured in the Oort-Cloud comet C/2002 T7 (LINEAR) through ground-based observations of the OH A [SUP]2[/SUP]Σ[SUP]+[/SUP] - X [SUP]2 ... [more ▼]

The [SUP]16[/SUP]OH/[SUP]18[/SUP]OH and OD/OH isotope ratios are measured in the Oort-Cloud comet C/2002 T7 (LINEAR) through ground-based observations of the OH A [SUP]2[/SUP]Σ[SUP]+[/SUP] - X [SUP]2[/SUP]Π[SUB]i[/SUB] ultraviolet bands at 3063 à (0, 0) and 3121 à (1, 1) obtained with the Very Large Telescope (VLT) feeding the Ultraviolet-Visual Echelle Spectrograph (UVES). From the [SUP]16[/SUP]OH/[SUP]18[/SUP]OH ratio, we find [SUP]16[/SUP]O/[SUP]18[/SUP]O = 425 ± 55, equal within the uncertainties to the terrestrial value and to the ratio measured in other comets, although marginally smaller. We also estimate OD/OH from which we derive D/H = 2.5 ± 0.7à 10[SUP]-4[/SUP] in water. This value is compatible with the water D/H ratios evaluated in other comets and is marginally higher than the terrestrial value. Based on observations collected at the European Southern Observatory, Paranal, Chile (ESO Programme 073.C-0525). [less ▲]

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See detailIsotopic abundance in the CN coma of comets: Ten years of measurements
Schulz, R.; Jehin, Emmanuel ULg; Manfroid, Jean ULg et al

in Planetary and Space Science (2008), 56

Over the past 10 years the isotopic ratios of carbon ([SUP]12[/SUP]C/[SUP]13[/SUP]C) and nitrogen ([SUP]14[/SUP]N/[SUP]15[/SUP]N) have been determined for a dozen comets, bright enough to allow obtaining ... [more ▼]

Over the past 10 years the isotopic ratios of carbon ([SUP]12[/SUP]C/[SUP]13[/SUP]C) and nitrogen ([SUP]14[/SUP]N/[SUP]15[/SUP]N) have been determined for a dozen comets, bright enough to allow obtaining the required measurements from the ground. The ratios were derived from high-resolution spectra of the CN coma measured in the B[SUP]2[/SUP]â [SUP]+[/SUP]â X[SUP]2[/SUP]â [SUP]+[/SUP] (0, 0) emission band around 387 nm. The observed comets belong to different dynamical classes, including dynamically new as well as long- and short-period comets from the Halley- and Jupiter-family. In some cases the comets could be observed at various heliocentric distances. All values determined for the carbon and nitrogen isotopic ratios were consistent within the error margin irrespective of the type of comet or the heliocentric distance at which it was observed. Our investigations resulted in average ratios of [SUP]12[/SUP]C/[SUP]13[/SUP]C=91±21 and nitrogen [SUP]14[/SUP]N/[SUP]15[/SUP]N=141±29. Whilst the value for the carbon isotopic ratio is in good agreement with the solar and terrestrial value of 89, the nitrogen isotopic ratio is very different from the telluric value of 272. [less ▲]

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See detailHigh-dispersion Spectroscopic Observations Of 8P/Tuttle With VLT/CRIRES
Kobayashi, Hitomi; Bockelee-Morvan, D.; Dello Russo, N. et al

in Bulletin of the American Astronomical Society (2008, September 01), 40

We present near-infrared observations of organic molecules in comet 8P/Tuttle. Comet 8P/Tuttle is a Halley-type comet and its last perihelion was in early January 2008. Our observations were carried out ... [more ▼]

We present near-infrared observations of organic molecules in comet 8P/Tuttle. Comet 8P/Tuttle is a Halley-type comet and its last perihelion was in early January 2008. Our observations were carried out on January 28 and February 4 using CRIRES (CRyogenic high-resolution InfraRed Echelle Spectrograph) at the Very Large Telescope (VLT). We used a 0.2" slit which provided a spectral resolving power of 80,000. We detected H[SUB]2[/SUB]O, OH, HCN, C[SUB]2[/SUB]H[SUB]2[/SUB] on Jan 28, and H[SUB]2[/SUB]O, OH, CH[SUB]4[/SUB], C[SUB]2[/SUB]H[SUB]6[/SUB], and CH[SUB]3[/SUB]OH on Feb 4. We find that 8P/Tuttle is depleted in HCN, C[SUB]2[/SUB]H[SUB]2[/SUB] and C[SUB]2[/SUB]H[SUB]6[/SUB] relative to H[SUB]2[/SUB]O compared with most other Oort cloud comets studied to date. Perhaps these depletions suggest that 8P/Tuttle formed in a different region from most Oort cloud comets, but it is also possible that the depletions are caused by repeated passages through the inner solar system. [less ▲]

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See detailLarge Excess of Heavy Nitrogen in Both Hydrogen Cyanide and Cyanogen from Comet 17P/Holmes
Bockelée-Morvan, D.; Biver, N.; Jehin, Emmanuel ULg et al

in Astrophysical Journal (2008), 679(Letters), 49-52

From millimeter and optical observations of the Jupiter-family comet 17P/Holmes performed soon after its huge outburst of 2007 October 24, we derive [SUP]14[/SUP]N/[SUP]15[/SUP]N = 139 +/- 26 in HCN and ... [more ▼]

From millimeter and optical observations of the Jupiter-family comet 17P/Holmes performed soon after its huge outburst of 2007 October 24, we derive [SUP]14[/SUP]N/[SUP]15[/SUP]N = 139 +/- 26 in HCN and [SUP]14[/SUP]N/[SUP]15[/SUP]N = 165 +/- 40 in CN, establishing that HCN has the same nonterrestrial isotopic composition as CN. The same conclusion is obtained for the long-period comet C/1995 O1 (Hale-Bopp) after a reanalysis of previously published measurements. These results are compatible with HCN being the prime parent of CN in cometary atmospheres. The [SUP]15[/SUP]N excess relative to the Earth's atmospheric value indicates that N-bearing volatiles in the solar nebula underwent important N isotopic fractionation at some stage of solar system formation. HCN molecules never isotopically equilibrated with the main nitrogen reservoir in the solar nebula before being incorporated in Oort Cloud and Kuiper Belt comets. The [SUP]12[/SUP]C/[SUP]13[/SUP]C ratios in HCN and CN are measured to be consistent with the terrestrial value. [less ▲]

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See detailNitrogen Isotope Ratios in Comets. ESO Astrophysics Symposia
Cochran, Anita L; Jehin, Emmanuel ULg; Manfroid, Jean ULg et al

in Precision Spectroscopy in Astrophysics (2008)

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See detailA Search for Escaping Water from Ceres' Poles
Rousselot, P.; Mousis, O.; Dumas, C. et al

in Asteroids, Comets, Meteors 2008 (2008)

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See detailIOT Overview: Optical Multi-Object Spectrographs
Schmidtobreick, L.; Bagnulo, S.; Jehin, Emmanuel ULg et al

in Kaufer, A. (Ed.) The 2007 ESO Instrument Calibration Workshop (2008)

We give an introduction to the several instruments that ESO operates and which are able to perform optical multi-object spectroscopy. We point out the standard ways of reducing these spectra, the problems ... [more ▼]

We give an introduction to the several instruments that ESO operates and which are able to perform optical multi-object spectroscopy. We point out the standard ways of reducing these spectra, the problems that occur, and the way we deal with them. A short introduction is given on how the quality control is performed. [less ▲]

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See detailModelling the Fringing of the FORS2 CCD
Walsh, J. R.; Kuntschner, H.; Jehin, Emmanuel ULg et al

in Kaufer, A. (Ed.) The 2007 ESO Instrument Calibration Workshop (2008)

Thinned CCD detectors display fringing which arises from the interference of multiply reflected light in the layers of the CCD. If the layer construction - the thicknesses and refractive indexes of the ... [more ▼]

Thinned CCD detectors display fringing which arises from the interference of multiply reflected light in the layers of the CCD. If the layer construction - the thicknesses and refractive indexes of the layers - is known, then the observed fringing can be accurately modelled and used to correct imaging and spectroscopic data for its effects. In practice the specifications on the actual deposited layer thicknesses may not be known to sufficient accuracy to predict the fringe behaviour. Thus calibration data, in the form of monochromatic flat fields, is required and can be modelled using the technique outlined by Malamuth et al. 2003, which has been applied to ACS CCDs. [less ▲]

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See detailPhotometry with FORS
Freudling, W.; Møller, P.; Patat, F. et al

in Kaufer, A. (Ed.) The 2007 ESO Instrument Calibration Workshop (2008)

Photometric calibration observations are routinely carried out with all ESO imaging cameras in every clear night. The nightly zeropoints derived from these observations are accurate to about 10%. Recently ... [more ▼]

Photometric calibration observations are routinely carried out with all ESO imaging cameras in every clear night. The nightly zeropoints derived from these observations are accurate to about 10%. Recently, we have started the FORS Absolute Photometry Project (FAP) to investigate, if and how percent-level absolute photometric accuracy can be achieved with FORS1, and how such photometric calibration can be offered to observers. We found that there are significant differences between the sky-flats and the true photometric response of the instrument which partially depend on the rotator angle. A second order correction to the sky-flat significantly improves the relative photometry within the field. We demonstrate the feasibility of percent level photometry and describe the calibrations necessary to achieve that level of accuracy. [less ▲]

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See detailOptical Observations of Comet McNaught from La Silla
Snodgrass, C.; Fitzsimmons, A.; Jehin, Emmanuel ULg et al

in LPI contribution 1405 (2008)

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See detailOptical Spectroscopy of the B and C Fragments of Comet 73P/Schwassmann-Wachmann 3 at the ESO VLT
Jehin, Emmanuel ULg; Manfroid, Jean ULg; Kawakita, H. et al

in LPI contribution 1405 (2008)

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See detailA Multi-Wavelength Simultaneous Study of the Composition of the Halley-Family Comet 8P/Tuttle at the VLT
Bockelée-Morvan, Dominique; Dello Russo, N.; Jehin, Emmanuel ULg et al

in LPI contribution 1405 (2008)

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See detailA Fluorescence Model for 12C13C in Comets
Rousselot, P.; Jehin, Emmanuel ULg; Manfroid, Jean ULg et al

in LPI contribution 1405 (2008)

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See detailCarbon and Nitrogen Isotopic Ratios in Comets
Jehin, Emmanuel ULg; Manfroid, Jean ULg; Hutsemekers, Damien ULg et al

in LPI contribution 1405 (2008)

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See detailISM Studies of GRB 030329 with High-Resolution Spectroscopy
Thöne, Christina C; Greiner, Jochen; Savaglio, Sandra et al

in Astrophysical Journal (2007), 671

We present early Very Large Telescope UV-Visual Echelle Spectrograph (VLT UVES) high-resolution spectra of the afterglow of GRB 030329 at redshift z=0.16867+/-0.00001. In contrast to other spectra from ... [more ▼]

We present early Very Large Telescope UV-Visual Echelle Spectrograph (VLT UVES) high-resolution spectra of the afterglow of GRB 030329 at redshift z=0.16867+/-0.00001. In contrast to other spectra from this burst, both emission and absorption lines were detected. None of them showed any temporal evolution. From the emission lines, we determine the properties of the host galaxy, which has a star formation rate (SFR) of 0.198 M[SUB]solar[/SUB] yr[SUP]-1[/SUP] and a low metallicity of 0.17 Z[SUB]solar[/SUB]. Given the low total stellar host mass logM[SUB]*[/SUB]=7.75+/-0.15 M[SUB]solar[/SUB] and an absolute luminosity m[SUB]B[/SUB]=-16.29, we derive specific SFRs (SSFR) of logSFR=-8.5 yr[SUP]-1[/SUP] and SFR = 15.1 M[SUB]solar[/SUB] yr[SUP]-1[/SUP] L[SUP]-1[/SUP][SUB]*[/SUB]. This fits well into the picture of GRB hosts as being low-mass, low-metallicity, actively star-forming galaxies. The Mg II and Mg I absorption lines from the host show multiple narrow (Doppler width b=5-12 km s[SUP]-1[/SUP]) components spanning a range of v~230 km s[SUP]-1[/SUP], mainly blueshifted compared to the redshift from the emission lines. These components are likely probing outflowing material of the host galaxy, which could arise from former galactic superwinds, driven by supernovae from star-forming regions. Similar features have been observed in QSO spectra. The outflowing material has high column densities of logN[SUB]MgII[/SUB]=13.99+/-0.04 cm[SUP]-2[/SUP] and logN[SUB]MgI[/SUB]=12.39+/-0.04 cm[SUP]-2[/SUP] and the nonvariability of the column densities implies a distance of at least 560 pc from the burst, further supporting an outflow scenario. Based on ESO proposal 70.D-0087. [less ▲]

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See detailSmall Scale Structure in the ISM towards IC 2391 and NGC 6475
Smoker, J. V.; Hunter, I.; Keenan, F. P. et al

in Haverkorn, M.; Goss, M. (Eds.) SINS - Small Ionized and Neutral Structures in the Diffuse Interstellar Medium (2007, July 01)

We describe UVES spectroscopic observations towards early-type stars located in the nearby open clusters IC 2391 (D=175 pc) and NGC 6475/M 7 (D=301 pc), with resolution ˜80,000 and S/N ratio per pixel of ... [more ▼]

We describe UVES spectroscopic observations towards early-type stars located in the nearby open clusters IC 2391 (D=175 pc) and NGC 6475/M 7 (D=301 pc), with resolution ˜80,000 and S/N ratio per pixel of ˜140 to ˜360. The aim is to investigate the small-scale structure variations within parts of the local ISM and determine how they are dependent on element and ionisation stage observed, thus providing information on cloud parameters such as structure and sizes. The data used are taken from on-line versions of the Paranal Observatory Project (POP: http://www.eso.org/uvespop). A total of 25 early-type stars (A and B-type) are present in our sample towards IC 2391 with 23 towards NGC 6475/M 7, and enable us to probe differences in column densities on scales from ˜0.07--7.3-pc and ˜0.05---4.9-pc (in the respective clusters) for the optical transitions detected (Ti II (3383Å), Ca II (3933Å), Na I (5889, 5895Å) and K I (7698Å)). Towards NGC 6475 the Ca II column density is found to be constant to ˜0.15 dex over scales of ˜0.4--4-pc. A much greater scatter in the measurements for Na I D is observed with differences of up to ˜0.45 dex in sightlines separated by ˜4 pc. In the future work we will perform the same analysis for Ti II and K I towards both clusters. [less ▲]

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