Contributed Talk - Splinter SMBHs

Wednesday, 23 September 2020, 09:20   (virtual room K)

Magnetic effect on the direct collapse gas cloud

Shingo Hirano, Masahiro N. Machida
Kyushu University

The origin of super-massive black holes (about one billion solar-masses) in the early universe (redshift z~7) remains poorly understood. Gravitational collapse of a massive primordial gas cloud is a promising initial process, but theoretical studies have difficulty growing the black hole fast enough. We focus on the magnetic effect on the star formation occurred in the atomic-cooling gas cloud. Using a three-dimensional resistive magnetohydrodynamical simulation, we investigate the formation of star-forming cloud cores in the atomic-cooling gas cloud with different initial magnetic field strengths. Our simulations show that the primordial magnetic seed field can be quickly amplified after the protostar formation. The strong magnetic field efficiently extracts angular momentum from accreting gas and increases the accretion rate onto the primary star. The number of fragments decreases as they merge with the primary star. We conclude that the magnetic field supports the direct collapse scenario of the massive star formation. In this talk, we also discuss the magnetic effect on the metal-enriched atomic-cooling gas clouds.