![]() ![]() 2007) this source also shows a barely resolved central condensation that is probably in rotation. CO maps of 89 Her show an extended component expanding at about 5 km s -1, whose emission dominates the line wings (Bujarrabal et al. Remarkably, gas in slow expansion has also been detected in some of these post-AGB objects. Profiles of this kind are also found in disks around young stars, and they have been proven to be very reliable indicators of rotating disks, both on theoretical and observational grounds. Recent single-dish observations of 12CO and 13CO mm-wave emission in a sample of similar post-AGB stars (close binary stars with low-mass nebulae and indications of compact disks) systematically yielded characteristic line profiles, with a prominent single or double peak and moderate-velocity wings, which are strikingly similar to those of the Red Rectangle (Bujarrabal et al. The inserts in the two last panels show the beam width. The HST optical image is also displayed, and the last panel shows the 0.85mm continuum image zoomed by a factor 2 and with contours ☐.0015, 0.0045, 0.0135, 0.0405, 0.1215, and 0.3645 Jy/beam. The LSR velocity is indicated in the upper-left corners. Van Winckel 2003).ĪLMA 12CO J = 3−2 observations of the Red Rectangle. It also shows properties, such as a near-infrared (NIR) excess that is indicative of hot dust kept close to the stellar system, which suggest the presence of a very compact disk (e.g. It consists of the equatorial rotating disk plus a spectacular axisymmetric nebula seen in the visible, surrounding a double stellar system (Men’shchikov et al. The Red Rectangle is a well studied PPN and, curiously, one of the post-asymptotic giant branch (AGB) objects that do not show massive and very fast outflows. However, only one of these putative disks has been identified well to date, which was by means of interferometric maps of 12CO J = 1−0 and J = 2−1 emission in the Red Rectangle (Bujarrabal et al. These outflows carry too much linear momentum to be powered by momentum transfer from stellar photons, and the presence of disks rotating around the central stars and reaccretion from them are often postulated for explaining the nebular dynamics (e.g., Soker 2001 Frank & Blackman 2004). Many protoplanetary nebulae (PPNe) show very massive (~0.1 M ⊙) and fast (30–200 km s -1) bipolar outflows, which are thought to be crucial in the formation of planetary nebulae see, e.g., Bujarrabal et al. From our observations and preliminary modeling of the data, we confirm the previously known properties of the disk and obtain a first description of the structure, dynamics, and physical conditions of the outflow.Īppendix A is available in electronic form at Together with an equatorial disk in rotation, we find a low-velocity outflow that more or less occupies the region situated between the disk and the optical X-shaped nebula. These observations provide an unprecedented description of the complex structure of this source. We obtained high-quality ALMA observations of 12CO and 13CO J = 3−2 and 12CO J = 6−5 line emission in the Red Rectangle, the only post-AGB/protoplanetary object for which a disk in rotation has been mapped. So far, both disks and outflows have not been observed simultaneously. We aim to study equatorial disks in rotation and axial outflows in post-AGB objects so as to disclose the formation and shaping mechanisms in planetary nebulae. ![]() Leuven, CelestijnenlaanĬentro de Astrobiología (CSIC-INTA), ESAC Campus, 28691 VillanuevaĬentro de Astrobiología (CSIC-INTA), Ctra. Observatorio Astronómico Nacional (OAN-IGN),Īlcalá de de Radioastronomie Millimétrique,ģ00 rue de la Piscine, 38406 Saint Martin Astronomical objects: linking to databases.Including author names using non-Roman alphabets. ![]() Suggested resources for more tips on language editing in the sciences Punctuation and style concerns regarding equations, figures, tables, and footnotes ![]()
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