EDP Sciences
Free access
Volume 503, Number 2, August IV 2009
Page(s) 477 - 482
Section Interstellar and circumstellar matter
DOI http://dx.doi.org/10.1051/0004-6361/200912238
Published online 23 June 2009
A&A 503, 477-482 (2009)
DOI: 10.1051/0004-6361/200912238

The angular momentum of condensations within elephant trunks

V. Lora1, A. C. Raga2, and A. Esquivel2

1  Instituto de Astronomía, Universidad Nacional Autónoma de México, Ap. 70-468, 04510, D.F México
2  Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ap. 70-543, 04510, D.F México
    e-mail: raga@nucleares.unam.mx

Received 31 March 2009 / Accepted 22 May 2009

Aims. The radiation from newly born stars photoevaporates their parental neutral cloud, leading to the formation of dense clumps that will eventually form stars.
Methods. We present 3D simulations of the interaction of a neutral cloud with an external ionising radiation field, and compute the angular momenta of these collapsing clumps.
Results. The angular momenta of these collapsing clumps show that they have preferential orientations mostly perpendicular to the direction of the incident ionising photon field. Therefore, the axes of the jet systems that will be eventually ejected (from the star + accretion disk systems that will form) will be oriented approximately perpendicular to the direction to the photoionising source.

Key words: ISM: kinematics and dynamics -- ISM: clouds -- ISM: HII regions -- stars: formation

© ESO 2009