The cool circumstellar environment of IRAS 08182-6000: radiative transfer modelling of TiO absorption bands

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Radiative Transfer, Stars: Agb And Post-Agb, Circumstellar Matter, Stars: Individual: Iras 08182-6000, Stars: Variables: Other, Infrared: Stars

Scientific paper

IRAS 08182-6000 has very red infrared colours, with an excess at K and L, and a silicate absorption feature at 9.7 μm. Optical spectra show strong, narrow absorption bands of TiO and AlO and weaker bands of VO that are indicative of formation in a very cool region, superimposed on a late F-type or early G-type spectrum. It is similar to the unusual star U Equ = IRAS 20547+0247 and both are high-velocity stars. These characteristics, together with spectroscopic indications of low surface gravity, suggest that these stars are of low mass and are possibly at a post-AGB stage of evolution. IRAS 08182-6000 brightened by several magnitudes during 12 yr of photometric observation. Photospheric and some circumstellar atomic absorption lines are evident, as well as atomic lines seen in emission that differ in radial velocity from those in absorption by c. 50 km s-1. Molecular bands of the γ, γ' and α systems of circumstellar TiO have been modelled using a one-dimensional radiative transfer code that makes use of the most recent laboratory and theoretical spectroscopic data on TiO. It was found necessary to invoke a non-local thermodynamic equilibrium model, which resulted in the determination of different rotational, spin-orbit and vibrational temperatures for the TiO gas, all of which lie well below the temperature at which TiO begins to deplete from the gas phase due to grain formation.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The cool circumstellar environment of IRAS 08182-6000: radiative transfer modelling of TiO absorption bands 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 The cool circumstellar environment of IRAS 08182-6000: radiative transfer modelling of TiO absorption bands, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The cool circumstellar environment of IRAS 08182-6000: radiative transfer modelling of TiO absorption bands will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1648566

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.