Theory Group Concepción

Departamento de Astronomía, Universidad de Concepción, Chile

The Formation of Low Mass Stars

It is a 5.4M_sun supersonic turbulent core (Mach # 5.4 and spectrum index p=2.0) collapsing with no initial solid body rotation. Baratropic EOS is in use.

There is very little initial thermal support against gravity in this model as alpha = E_therm/E_grav = 0.113, and also there is no rotational support against gravity since omega = 0 rad/s. Now with this supersonic turbulent gas core with Mach# 5.4 and spectrum index 'p' = 2.0, the core exhibited an expansion in original dimension. Nevertheless, there are primary and secondary filaments appearing during the course of collapse. The primary filament actually hosts so far 3 sinks and other potential sinks may arrive during model evolution. This model also showed multiple local density enhancements which under go local collapse despite an overall expansion of the core. One sink spitting gas as it accretes (gas + small fragment). This could be an episodic accretion burst hence the matter needs further investigation.

Here it is again (Mach # 5.4 and spectrum index p=2.0). Baratropic EOS is in use. Initial solid body rotation was also assigned this time (rotational energy was set to 10% of the gravitational potential energy). It can be seen that supersonic case didn't give respect to this assigned rotation and multiple rotational planes within collapsing gas have resulted for various fragments appearing during collapse (such as the two interacting BDs with disks eventually becoming a BD binary system). After quite a while the two sinks that formed binary system have started the slow accretion again. (one has already transformed from BD to VLM). The spiral around them was also getting stronger in density and hence have given birth to another sink (sink3). The resulting smaller mass sink3 is going to have dynamical interaction with the binary system which actually kicked it out of the system.

© Theory Group Concepcion 2019