Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-12-01
Astrophys.J.658:462-479,2007
Astronomy and Astrophysics
Astrophysics
20 pages, 12 figures, Accepted for publication in the Astrophysical Journal
Scientific paper
10.1086/511327
We present a new model-independent method of comparison of NIR visibility data of YSOs. The method is based on scaling the measured baseline with the YSO's distance and luminosity, which removes the dependence of visibility on these two variables. We use this method to compare all available NIR visibility data and demonstrate that it distinguishes YSOs of luminosity >1000L_sun (low-L) from YSOs of <1000L_sun (high-L). This confirms earlier suggestions, based on fits of image models to the visibility data, for the difference between the NIR sizes of these two luminosity groups. When plotted against the ``scaled'' baseline, the visibility creates the following data clusters: low-L Herbig Ae/Be stars, T Tauri stars, and high-L Herbig Be stars. The T Tau cluster is similar to the low-L Herbig Ae/Be cluster, which has ~7 times smaller ``scaled'' baselines than the high-L Herbig Be cluster. We model the shape and size of clusters with different image models and find that low-L Herbig stars are the best explained by the uniform brightness ring and the halo model, T Tauri stars with the halo model, and high-L Herbig stars with the accretion disk model. However, the plausibility of each model is not well established. Therefore, we try to build a descriptive model of the circumstellar environment consistent with various observed properties of YSOs. We argue that low-L YSOs have optically thick disks with the optically thin inner dust sublimation cavity and an optically thin dusty outflow above the inner disk regions. High-L YSOs have optically thick accretion disks with high accretion rates enabling gas to dominate the NIR emission over dust. Although observations would favor such a description of YSOs, the required dust distribution is not supported by our current understanding of dust dynamics.
Jurkic Tomislav
Vinkovic' Dejan
No associations
LandOfFree
Relation between the luminosity of young stellar objects and their circumstellar environment 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 Relation between the luminosity of young stellar objects and their circumstellar environment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Relation between the luminosity of young stellar objects and their circumstellar environment will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-671560