![]() ![]() ![]() ![]() Sketch of the SA technique (adapted from Whelan & Garcia 2008) showing the analysis of the long-slit spectra of a point source ( top) and a compact bipolar PN ( bottom). 2011) and a disk of 40 mas traced by water maser emission has been found in radio observations of the core of the young PNe K 3-35 ( Miranda et al. (2005) found a Keplerian disk of 900 mas in size at the center of AFGL 915, whereas disks of ~30 mas have been detected by MIDI-VLTI in M 2-9 and Mz 3 ( Chesneau et al. Meanwhile, radio and mid-IR spectroscopic and interferometric observations have found strong evidence of small-sized dust and/or gaseous disks at the core of a few proto-PNe and young PNe. IR observations have revealed asymmetries in post-AGB sources and early proto-PNe such as bipolar lobes, and pinched waists and bright cores that appear as dark lanes at optical wavelengths ( Suárez et al. 2007), the onset of asymmetry in PNe occurs during the short transition between the end of the AGB phase and the beginning of the PN phase, when they are optically obscured. De Marco (2009) proposed that disks might be associated with the binary evolution through a common-envelope phase.Īs revealed by multiwavelength observations in the mid-IR and radio ( Sahai et al. 2005) and/or binary systems ( Soker 1998). These PNe are believed to be sculpted by fast collimated outflows (jets), whose collimation and launch could be produced by strong magnetic fields ( García-Segura et al. The most axisymmetric PNe represent a challenge to the understanding of their formation, since they contradict the canonical generalized interacting stellar wind model (GISW, Balick & Frank 2002). PNe display an exceptional variety of morphologies whose shaping involves dramatic changes in the otherwise round envelopes of their progenitors. Planetary nebulae (PNe) emerge after the asymptotic giant branch (AGB) phase of low- and intermediate-mass stars ( 0.8 M ⊙< M i< 8 M ⊙). Planetary nebulae: shapes, shaping, and observational challenges is staff member of CSIC on temporal leave at the Universidad de Vigo. The results presented here open a new window in the search for the small-sized collimating agents that shape the complex morphologies of extremely axisymmetric PNe. The spectroscopic observations required to perform spectro-astrometry of sources in the transition towards the PN phase are less time-consuming and much more sensitive than VLTI IR observations. In IRAS 17516 −2525, the spectro-astrometric signal has a size of only 12 ± 5 mas, as detected in the Br γ line, whereas the structures found in SwSt 1 have sizes of 230 ± 29 mas in the line and 130 ± 21 mas in the Br γ line. ![]() Our exploratory study using CRyogenic high-resolution Infra-Red Echelle Spectrograph (CRIRES) commissioning data of the proto-PN IRAS 17516 −2525 and the young PN SwSt 1 has revealed small-sized structures after the spectro-astrometric analysis of the two sources. Inspired by the successful detection of proto-planetary disks using spectro-astrometric observations, we apply this technique here for the first time to search for subarcsecond structures in PNe. Interferometric VLTI IR observations have revealed compelling evidence of disks at the cores of PNe, but the limited sensitivity, strong observational constraints, and limited spatial coverage place severe limits on a universal use of this technique. Sources in this transition phase are compact and emit intensely in infrared wavelengths, making high spatial resolution observations in the infrared mandatory to investigate the shaping process of PNe. The onset of asymmetry in planetary nebulae (PNe) occurs during the short transition between the end of the asymptotic giant branch (AGB) phase and the beginning of the PN phase. 2, 85748 Garching bei München, GermanyĮ-mail: Universidad de Vigo, Departamento de Física Aplicada, Facultad de Ciencias, Campus Lagoas-Marcosende s/n, 36310 Vigo, SpainĮ-mail: Consejo Superior de Investigaciones Científicas (CSIC), C/ Serrano 117, 28006 Madrid, Spainĥ Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637, USA Seifahrt 5ġ Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la Astronomía s/n, 18008 Granada, SpainĮ-mail: European Southern Observatory (ESO), Karl Schwarzschild Str. 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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