| |
 |
| Paper: |
The ROSAT Field Sources --- What are they? |
| Volume: |
154, Cool Stars, Stellar Systems and the Sun: Tenth Cambridge Workshop |
| Page: |
237 |
| Authors: |
Caillault, J.-P.; Briceno, C.; Martin, E. L.; Palla, F.; Wichmann, R. |
| Abstract: |
Recent studies using the ROSAT All-Sky Survey towards nearby star-forming regions have identified a widely dispersed population of X-ray active stars and have suggested that these objects are older PMS stars located far from molecular clouds. Another group, however, has presented a simple model assuming continuing star formation over the past 10^8 yrs that quantitatively reproduces the number, surface density, X-ray emission, and optical properties of the RASS sources, leading to the argument that these stars are not PMS stars, but young MS stars of ages up to approximately 10^8 yrs. A third party notes that the similarity between molecular cloud lifetimes and the ambipolar diffusion timescale implies that star formation does not take place instantaneously, nor at a constant rate. They thus argue that the probability of finding a large population of old stars in a star-forming region is intrinsically very small and that the post-T Tauri problem is by and large nonexistent. |
|
|
|
|
|
