Cosmic dust charge shapes star formation
doi:10.1038/nindia.2015.108 Published online 26 August 2015
Researchers have gained new insights into how charge fluctuation in dust grains affects the gravitational collapse of dusty plasmas in star-forming regions in space1. These insights provide clues about how stars form from collapsing clouds of dust and gas.
The dust grains in these clouds are immersed in the ambient plasma and cosmic radiation. The plasma particles, which include electrons and ions, charge the dust grains. The charge of the dust grains fluctuates with the local conditions and this fluctuating charge is suspected to affect the dusty plasma as it increases in mass and eventually collapses to form a star.
In the present study, the researchers developed a theoretical model by performing numerical calculations. They found that the dust charge fluctuation in conjunction with radiative cooling and the polarization force have a destabilizing effect, whereas the thermal velocity and cyclotron frequency of the dust have a stabilizing influence on the growth rate of a collapsing gas cloud containing a dusty plasma. The scientists consider that gravitational collapse eventually leads to star formation.
The researchers say that their model could be useful for understanding the formation of a dense dusty molecular cloud through gravitational and radiative condensation, particularly when the dust charge fluctuation and polarization force are dominant in such a system.
1. Prajapati, R. P. et al. Influence of dust charge fluctuation and polarization force on radiative condensation instability of magnetized gravitating dusty plasma. Phys. Lett. A (2015) doi: 10.1016/j.physleta.2015.08.007