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Astron. Astrophys. 345, 1049-1053 (1999)

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Pulsational mode of gravitational collapse and its impact on the star formation

C.B. Dwivedi 1, A.K. Sen 2 and S. Bujarbarua 3

1 Institute of Advanced Study in Science and Technology, Khanapara, Guwahati 781 022, India (cbd@iasstghy.ren.nic.in)
2 Department of Physics, Assam University, Silchar 788 014, India (aksen@dte.vsnl.net.in)
3 Centre of Plasma Physics, Dispur, Guwahati 781 006, India (sbj@ipprghy.ren.nic.in)

Received 19 June 1998 / Accepted 2 February 1999


The gravitational condensation of a collapsing dust mass is always inhibited by the acoustic viscosity, restricting thereby the unstable scale size. In this paper we show that, if some of the dust particles (in the collapsing mass) are ionised due to plasma environment, a new mode of Jeans condensation namely the Pulsational Mode of the Gravitational Collapse (PMGC) seems to be a likely phenomenon around a fluctuation scale size of the order of the critical Jeans length. This novel mode of the gravitational collapse is a consequence of the finite linear gravito-electrostatic coupling due to partial ionisation of the collapsing mass. It may be interpreted as a time synchronised resonant linear superposition of a purely hybrid oscillator-like mode (gravito-electrostatic oscillator) and a purely growing (Jeans-like) mode over a levitational kind of equilibrium around the critical Jeans length.

Key words: plasmas – stars: formation – ISM: dust, extinction

Send offprint requests to: A.K. Sen

© European Southern Observatory (ESO) 1999

Online publication: April 28, 1999