Formation of filaments in the interstellar medium

Séminaire IPAG de Patrick Hennebelle (CEA/Saclay), jeudi 29 janvier 2015 à 11h00, IPAG seminar room

While the existence of massive filaments is known since several decades, the Herschel Space Observatory has revealed that filaments are ubiquitous in the ISM and has permitted to quantify their properties. Interestingly, many of them do not appear to be self-gravitating implying that self-gravity cannot be the only mechanism at the origin of their existence. Deciphering the various regimes and processes at play in this context, is important. First of all, filaments could possibly have an impact on star formation, second of all and more generally, they are consequences of the dynamical processes responsible of the molecular cloud and ISM evolution and therefore constitute an important test for the corresponding theories.

In the talk, I will first present some of the results recently obtained with Herschel. I will then describe various studies, which have been specifically addressing these questions. I will distinguish between self-gravitating filaments and not self-gravitating ones and propose that those ones, at least, are consequences of the turbulent strain and magnetic field.