Oral Presentation

The role of the magnetic field in the formation of stellar clusters (Remote)

Author(s): Aina Palau (UNAM), Qizhou Zhang, Josep M. Girart, Junhao Liu, Ramprasad Rao, Patrick M. Koch, Robert Estalella, Huei-Ru Vivien Chen, Hauyu Baobab Liu, K. Qiu, Z.-Y. Li, L. Zapata, S. Bontemps, Paul T. P. Ho, H. Beuther, T.-C. Ching, H. Shinnaga, A. Ahmadi

Presenter: Aina Palau (IRyA-UNAM)

Theoretical and numerical works clearly indicate that a strong magnetic field should suppress fragmentation in massive dense cores, the stellar cluster precursors. However, this has never been tested observationally in a relatively large sample of fragmenting massive dense cores. Here we present the polarization data obtained with the Submillimeter Array Legacy Survey of Zhang et al. to build a sample of 18 massive dense cores where both fragmentation and magnetic field properties were studied in a uniform way. We measured the fragmentation level within the field of view common to all regions, of ∼ 0.15 pc, with a mass sensitivity of about 0.5 Msun, and a spatial resolution of ∼ 1000 AU. On the other hand, the magnetic field strength was estimated using different methods for which the dispersion of the polarization position angles, the velocity dispersion of the H13CO+(4–3) gas, and the density of each core, all averaged within 0.15 pc, where measured. For the first time, a tentative correlation was found between the fragmentation level and the mass-to-magnetic flux ratio, as predicted by numerical and theoretical works. This suggests that the magnetic field could play an important role in the fragmentation process of stellar cluster precursors, and prompts to carry out further projects using larger samples and more sensitive arrays.