Forming a Primordial Star in a Relic HII Region

Technical Report · Tue Apr 12 04:00:00 EDT 2005

DOI:https://doi.org/10.2172/839853· OSTI ID:839853

O'Shea, Brian ^[1]

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1. SLAC

There has been considerable theoretical debate over whether photoionization and supernova feedback from the first Population III stars facilitate or suppress the formation of the next generation of stars. We present results from an Eulerian adaptive mesh refinement simulation demonstrating the formation of a primordial star within a region ionized by an earlier nearby star. Despite the higher temperatures of the ionized gas and its flow out of the dark matter potential wells, this second star formed within 23 million years of its neighbor's death. The enhanced electron fraction within the HII region catalyzes rapid molecular hydrogen formation that leads to faster cooling in the subsequent star forming halos than in the first halos. This ''second generation'' primordial protostar has a much lower accretion rate because, unlike the first protostar, it forms in a rotationally supported disk of {approx} 10-100 M{center_dot}. In contrast to unpreprocessed regions, such configurations may allow binaries or multiple systems of lower mass stars to form. These first high resolution calculations offer insight into the impact of feedback upon subsequent populations of stars and clearly demonstrate how primordial chemistry promotes the formation of subsequent generations of stars even in the presence of the entropy injected by the first stars into the IGM.

• Research Organization: Stanford Linear Accelerator Center (SLAC), Menlo Park, CA
• Sponsoring Organization: SC
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 839853
• Report Number(s): SLAC-PUB-11122
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
CHEMISTRY
ELECTRONS
ENTROPY
FEEDBACK
HYDROGEN
NONLUMINOUS MATTER
PHOTOIONIZATION
PROTOSTARS
RESOLUTION
SIMULATION
STARS