Are cluster magnetic fields primordial?
← Research streamUsing fully nonlinear numerical and analytical investigation, the authors report that magnetic fields of about 10^-13 to 10^-11 G on scales of ~100 pc to 10 kpc could survive to the present under reasonable assumptions about magnetogenesis efficiency during c…
Study snapshot
Abstract
We present results of a detailed and fully nonlinear numerical and analytical investigation of magnetic field evolution from the very earliest cosmic epochs to the present. We find that, under reasonable assumptions concerning the efficiency of a putative magnetogenesis era during cosmic phase transitions, surprisingly strong magnetic fields 10(-13)-10(-11) G on comparatively small scales 100 pc-10 kpc may survive to the present. Building on prior numerical work on the evolution of magnetic fields during the course of gravitational collapse of a cluster, which indicates that precollapse fields of approximately 4 x 10(-12) G extant on small scales may suffice to produce clusters with acceptable Faraday rotation measures, we argue that it seems possible for cluster magnetic fields to be entirely of primordial origin.
AI evidence extraction
Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.
Main findings
Using fully nonlinear numerical and analytical investigation, the authors report that magnetic fields of about 10^-13 to 10^-11 G on scales of ~100 pc to 10 kpc could survive to the present under reasonable assumptions about magnetogenesis efficiency during cosmic phase transitions. They argue that precollapse fields of ~4 × 10^-12 G on small scales may be sufficient to yield galaxy clusters with acceptable Faraday rotation measures, suggesting cluster magnetic fields could be entirely primordial in origin.
Outcomes measured
- magnetic field evolution (cosmic epochs to present)
- survival of primordial magnetic fields (strength and scale)
- cluster Faraday rotation measures (as acceptability criterion)
Limitations
- Assumptions about efficiency of magnetogenesis during cosmic phase transitions are described as 'reasonable' but not specified in the abstract
- Findings are based on numerical and analytical modeling rather than direct experimental/epidemiologic observation
- Relies in part on prior numerical work for the link between precollapse fields and Faraday rotation measures
View raw extracted JSON
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"outcomes": [
"magnetic field evolution (cosmic epochs to present)",
"survival of primordial magnetic fields (strength and scale)",
"cluster Faraday rotation measures (as acceptability criterion)"
],
"main_findings": "Using fully nonlinear numerical and analytical investigation, the authors report that magnetic fields of about 10^-13 to 10^-11 G on scales of ~100 pc to 10 kpc could survive to the present under reasonable assumptions about magnetogenesis efficiency during cosmic phase transitions. They argue that precollapse fields of ~4 × 10^-12 G on small scales may be sufficient to yield galaxy clusters with acceptable Faraday rotation measures, suggesting cluster magnetic fields could be entirely primordial in origin.",
"effect_direction": "unclear",
"limitations": [
"Assumptions about efficiency of magnetogenesis during cosmic phase transitions are described as 'reasonable' but not specified in the abstract",
"Findings are based on numerical and analytical modeling rather than direct experimental/epidemiologic observation",
"Relies in part on prior numerical work for the link between precollapse fields and Faraday rotation measures"
],
"evidence_strength": "insufficient",
"confidence": 0.74,
"peer_reviewed_likely": "yes",
"keywords": [
"primordial magnetic fields",
"magnetogenesis",
"cosmic phase transitions",
"galaxy clusters",
"Faraday rotation measures",
"numerical simulation",
"magnetic field evolution"
],
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}AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.
Identifiers and source
DOI: 10.1103/physrevlett.91.251301
PubMed: 14754103