Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-07-23
Astronomy and Astrophysics
Astrophysics
8 pages, 3 figures, accepted for publication in MNRAS
Scientific paper
10.1111/j.1365-2966.2008.13748.x
We have selected a small sample of post-AGB stars in transition towards the planetary nebula and present new Very Large Array multi-frequency high-angular resolution radio observations of them. The multi-frequency data are used to create and model the targets' radio continuum spectra, proving that these stars started their evolution as very young planetary nebulae. In the optically thin range, the slopes are compatible with the expected spectral index (-0.1). Two targets (IRAS 18062+2410 and 17423-1755) seem to be optically thick even at high frequency, as observed in a handful of other post-AGB stars in the literature, while a third one (IRAS 20462+3416) shows a possible contribution from cold dust. In IRAS 18062+2410, where we have three observations spanning a period of four years, we detect an increase in its flux density, similar to that observed in CRL 618. High-angular resolution imaging shows bipolar structures that may be due to circumstellar tori, although a different hypothesis (i.e., jets) could also explain the observations. Further observations and monitoring of these sources will enable us to test the current evolutionary models of planetary nebulae.
Buemi Carla
Cerrigone Luciano
Hora Joseph L.
Leto Paolo
Trigilio Corrado
No associations
LandOfFree
Radio continuum properties of young planetary nebulae does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Radio continuum properties of young planetary nebulae, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radio continuum properties of young planetary nebulae will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1122