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| HAL: hal-00003364, version 2 |
| arXiv: astro-ph/0411736 |
| Detailed view |  Export this paper |
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| Available versions: | v1 (2004-11-26) | v2 (2004-11-28) |
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| Dust temperature and density profiles of AGB and post-AGB stars from mid-infrared observations |
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| Eric Lagadec 1Djamel Mékarnia 1 |
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| (2004-11-26) |
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| First mid-infrared images of a sample of AGB and post-AGB carbon stars (V Hya, IRC +10216, CIT 6 and Roberts 22) obtained at La Silla Observatory (ESO, Chile) are reported. CIT 6 presents a cometary-like feature clearly seen in the 9.7$\mu$m image, Roberts 22 shows an envelope slightly elongated in the north-east direction while images of V Hya and IRC+10216 are roughly spherically symmetric. Using inversion technique, the dust emissivity was derived from the observed intensity profiles, allowing a determination of the grain temperature and density distributions inside the envelope for these stars. Dust masses and mass-loss rates were estimated for V\,Hya and IRC\,+10216. Our results are comparable to those obtained in previous studies if dust grains have dimensions in the range $\sim$\,0.01\,-\,0.2\,$\mu$m. Color maps suggest the presence of temperature inhomogeneities in the central regions of the dust envelopes. In the case of V Hya, an eccentric hot point, which direction coincides with the jet previously seen in [SII] emission, suggest that we are observing a material ejected in a previous mass-loss event. Bipolar lobes are clearly seen in the color maps of Roberts 22 and IRC +10216. |
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| 1: | Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE) |
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Université de Nice Sophia Antipolis (UNS) – CNRS : UMR6202 – Observatoire de la Cote d'Azur – INSU |
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| 2: | Astrophysique Relativiste Théories Expériences Métrologie Instrumentation Signaux (ARTEMIS) |
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Université de Nice Sophia Antipolis (UNS) – CNRS : UMR6162 – Observatoire de la Cote d'Azur – INSU |
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| 3: | Laboratoire d'Astrophysique de Grenoble (LAOG) |
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CNRS : UMR5571 – OSUG – INSU – Université Joseph Fourier - Grenoble I |
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| Subject | : | Sciences of the Universe/Astrophysics Physics/Astrophysics/Cosmology and Extra-Galactic Astrophysics |
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| AGB and post-AGB – circumstellar matter – mass-loss – imaging – Infrared |
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| hal-00003364, version 2 | |
| http://hal.archives-ouvertes.fr/hal-00003364 | |
| oai:hal.archives-ouvertes.fr:hal-00003364 | |
| From: Eric Lagadec | |
| Submitted on: Saturday, 27 November 2004 15:39:25 | |
| Updated on: Sunday, 28 November 2004 09:28:17 | |
