The distribution of low mass star forming regions

Extract

Our knowledge of the distribution of low mass stars (T-associations) in the Galaxy, as an indicator of star forming regions (SFR), is badly known due to an observational bias. A correlation with high-mass stars (OB-associations) will not solve the problem, because some well known SFR as Taurus and Chamaleonis seem to preferentially form low mass stars. One way to tackle this question is by invoking the distribution of known T Tauri stars (TTS) and the distribution of selected IRAS sources that are potential candidates to be new TTS. We must be aware, however, that an important number of TTS are not IRAS sources. Considering these distributions, we have found a smooth distribution of SFR along the local galactic plane. The number of TTS in each SFR is very variable probably due to a variable efficiency of star formation. Also there are some isolated TTS from SFR which could indicate the dissipation of old SFR or that some TTS can be formed from isolated very small clouds.