The Biermann Battery In Cosmological Mhd Simulations Of Population III Star Formation

Journal Article · Tue Jan 01 00:00:00 EST 2008 · The Astrophysical Journal

DOI:https://doi.org/10.1086/595617· OSTI ID:962238

Xu, Hao ^[1]; O' Shea, Brian W ^[1]; Li, Hui ^[1]; Li, Shengtai ^[1]; Norman, Michael L ^[2]; Collins, David C ^[2]

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1. Los Alamos National Laboratory
2. UCSD

We report the results of the first self-consistent three-dimensional adaptive mesh refinement magnetohydrodynamical simulations of Population III star formation including the Biermann battery effect. We find that the Population III stellar cores formed including this effect are both qualitatively and quantitatively similar to those from hydrodynamics-only (non-MHD) cosmological simulations. We observe peak magnetic fields of {approx_equal} 10{sup -9} G in the center of our star-forming halo at z {approx_equal} 17.55 at a baryon density of n{sub B} {approx} 10{sup 10} cm{sup -3}. The magnetic fields created by the Biermann battery effect are predominantly formed early in the evolution of the primordial halo at low density and large spatial scales, and then grow through compression and by shear flows. The fields seen in this calculation are never large enough to be dynamically important (with {beta} {ge} 10{sup 15} at all times before the termination of our calculation), and should be considered the minimum possible fields in existence during Population III star formation. The lack of magnetic support lends credibility to assumptions made in previous calculations regarding the lack of importance of magnetic fields in Population III star formation. In addition, these magnetic fields may be seed fields for the stellar dynamo or the magnetorotational instability at higher densities and smaller spatial scales.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 962238
• Report Number(s): LA-UR-08-04552; LA-UR-08-4552; TRN: US0903405
• Journal Information: The Astrophysical Journal, Vol. 688, Issue 2; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
COMPRESSION
INSTABILITY
MAGNETIC FIELDS
SEEDS
SHEAR
STARS