VLBI OF AGB STARS · Very long Baseline Interferometric astrometry of SiO masers around AGB stars to track the mass loss processes
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2006-02-01 → 2008-01-31
- EU contribution
- €181,852
- Participants
- 1
- Scheme
- IIF
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Results in brief
Final Activity Report Summary - VLBI OF AGB STARS (Very Long Baseline Interferometric astrometry of SiO masers around AGB stars to track the mass loss processes)
We designed a new method of calibration for very long baseline interferometry (VLBI) at mm wavelengths. This allowed the images to be astrometrically aligned, i.e. to put them on a common reference frame. We used this new method to image SiO masers around asymtopic giant branch (AGB) stars which were also Mira type variables. This informed us whether the source had emission from the different transitions in the same point in the sky. With this information we could work out which of the competing models for the excitation of the SiO maser emission was closer to reality. This information, in turn, allowed us to relate the observed emission to the underlying conditions. Whereas we could not previously say how much mass loss from these stars, which went on to form the beautiful proto-plantentary nebulea, was required to produce the observed maser emission this now became possible, even though our results made clear that both models needed updating.
Data: CORDIS, © European Union
Project objective
The Observatorio Astronómico Nacional (OAN) is building a new 40 meter state of the art VLBI antenna, at Yebes, Spain. We will use my experience to integrate this into the European astronomical networks. We will then use its innovative optical system to develop the new calibration method of "astrometric frequency phase transfer for spectral line VLBI'' for the general astronomical community. We will use this method to align SiO maser multi-transition observations to a common reference frame, and confirm the offsets between the emission sites at different frequencies. In parallel we will use the Yebes antenna as a single dish to confirm that the maximum flux for the multi-transitions occur at the same time. Once we have the confirmation of emission stimulation occurring at the same time in different places we have shown that the maser stimulation is radiative, solving the long standing conflict in this field. Once the correct model is known the astronomical community can trace the mass loss processes of evolved stars. This project therefore: uses my experience to assist the European Research Area, begins a long term collaborative project by developing new techniques, and provides me with the training and the experience to return to Australia.""
Original text from CORDIS.
Participants
- FUNDACION GENERAL DE LA UNIVERSIDAD DE ALCALA - INSTITUTO GEOGRAFICO NACIONAL · ALCALA DE HENARESCoordinatorCity levelSpain
Links
Data: CORDIS, © European Union