Karine Demyk

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Recent ISO results allow new insights into the evolution of interstellar ices in the vicinity of massive protostars. The presence of CO 2 ice has recently been confirmed with the SWS (Short Wavelength Spectrometer) on-board ISO as a dominant ice component of interstellar grain mantles. The bending mode of CO 2 ice, currently observed toward many massive(More)
Using a radiative transfer code we have studied the dust shells of the two OH/IR stars IRAS 17004-4119 (OH344.93) and IRAS 17411-3154 (OH357). The ISO-SWS spectra of both sources exhibit deep amorphous silicate absorption bands at 9.8 and 17.5 μm together with crystalline silicate emission bands at 33.6, 40.5 and 43 μm. In both sources the 9.8 μm silicate(More)
We have studied the chemical composition of the silicates around the two massive protostellar objects RAFGL7009S (IRAS 18316-0602) and IRAS 19110+1045. The silicate features of both sources are similar. The position and shape of the 9.6 and 18 μm silicate bands coincide with those of amorphous pyroxene-type silicates. We find that the silicate features(More)
IRAS 04368+2557 is a solar-type (low-mass) protostar embedded in a protostellar core (L1527) in the Taurus molecular cloud, which is only 140 parsecs away from Earth, making it the closest large star-forming region. The protostellar envelope has a flattened shape with a diameter of a thousand astronomical units (1 AU is the distance from Earth to the Sun),(More)
Context. Hot cores in molecular clouds, such as Orion KL, Sgr B2, W51 e1/e2, are characterized by the presence of molecules at temperature high enough to significantly populate their low-frequency vibrationally excited states. For complex organic molecules, characterized by a dense spectrum both in the ground state and in the excited states, such as methyl(More)
Aims. We identify a prominent absorption feature at 1115 GHz, detected in first HIFI spectra towards high-mass star-forming regions, and interpret its astrophysical origin. Methods. The characteristic hyperfine pattern of the H2O ground-state rotational transition, and the lack of other known low-energy transitions in this frequency range, identifies the(More)
The Herschel and Planck missions have opened up the spectral domain in the far infrared and submillimeter range. This spectral domain reveals the emission of cold (T ≤ 50 K) dust grains of nanometer size (10-100 nm), emission which is used to study star formation, to estimate interstellar clouds masses and more generally to study the evolution of the(More)