Oral Presentation

The Effect of Magnetic Fields and Ambipolar Diffusion on the Column Density Probability Distribution Function in Molecular Clouds

Author(s): Sayantan Auddy (University of Western Ontario) Shantanu Basu (University of Western Ontario) Takahiro Kudoh (Nagasaki University)

Presenter: Sayantan Auddy (University of Western Ontario, Canada)

Simulations generally show that non-self-gravitating clouds have a lognormal column density probability distribution function (PDF), while self-gravitating clouds with active star formation develop a distinct power-law tail at high column density. Although the growth of the power law can be attributed to gravitational contraction leading to the formation of condensed cores, it is often debated if an observed lognormal shape is a direct consequence of supersonic turbulence alone, or even if it is really observed in molecular clouds. In this talk, I will discuss the effect of strong magnetic fields and turbulence on the evolution of the column density PDFs. I have used three-dimensional nonideal magnetohydrodynamic (MHD) simulations including ambipolar diffusion to study different initial conditions and the way they affect the shape of the PDF. Our results are interesting, including a distinct signature on how strong magnetic fields influence the power-law slope of the column density PDFs.