Gas modelling in the disc of HD 163296

Details Gas modelling in the disc of HD 163296 Gas modelling in the disc of HD 163296

2011-11-10

arxiv.org/abs/1111.2549v1

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

20 pages, 15 figures. Accepted for publication in A&A

Scientific paper

We present detailed model fits to observations of the disc around the Herbig Ae star HD 163296. This well-studied object has an age of ~ 4 Myr, with evidence of a circumstellar disc extending out to ~ 540AU. We use the radiation thermo-chemical disc code ProDiMo to model the gas and dust in the circumstellar disc of HD 163296, and attempt to determine the disc properties by fitting to observational line and continuum data. These include new Herschel/PACS observations obtained as part of the open-time key program GASPS (Gas in Protoplanetary Systems), consisting of a detection of the [OI]63mic line and upper limits for several other far infrared lines. We complement this with continuum data and ground-based observations of the 12CO 3-2, 2-1 and 13CO J=1-0 line transitions, as well as the H2 S(1) transition. We explore the effects of stellar ultraviolet variability and dust settling on the line emission, and on the derived disc properties. Our fitting efforts lead to derived gas/dust ratios in the range 9-100, depending on the assumptions made. We note that the line fluxes are sensitive in general to the degree of dust settling in the disc, with an increase in line flux for settled models. This is most pronounced in lines which are formed in the warm gas in the inner disc, but the low excitation molecular lines are also affected. This has serious implications for attempts to derive the disc gas mass from line observations. We derive fractional PAH abundances between 0.007 and 0.04 relative to ISM levels. Using a stellar and UV excess input spectrum based on a detailed analysis of observations, we find that the all observations are consistent with the previously assumed disc geometry.

Affiliated with

Also associated with

No associations

Rating

Gas modelling in the disc of HD 163296 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 Gas modelling in the disc of HD 163296, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gas modelling in the disc of HD 163296 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-728002