RADIO DETECTION OF GREEN PEAS: IMPLICATIONS FOR MAGNETIC FIELDS IN YOUNG GALAXIES
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Chakraborti-2012-RADIO DETECTION OF G.pdf
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Author(s)
Chakraborti, Sayan
Yadav, Naveen
Cardamone, Carolin
Ray, Alak
Date Issued
January 2012
Journal
Astrophysical Journal. Letters
Publisher
IOP Publishing
Citation
Chakraborti, Sayan, Naveen Yadav, Carolin Cardamone, and Alak Ray. “RADIO DETECTION OF GREEN PEAS: IMPLICATIONS FOR MAGNETIC FIELDS IN YOUNG GALAXIES.” The Astrophysical Journal 746, no. 1 (January 19, 2012): L6. © 2012 The American Astronomical Society
Version
Final published version
Abstract
Green Peas are a new class of young, emission line galaxies that were discovered by citizen volunteers in the Galaxy Zoo project. Their low stellar mass, low metallicity, and very high star formation rates make Green Peas the nearby (z ~ 0.2) analogs of the Lyman break galaxies which account for the bulk of the star formation in the early universe (z ~ 2-5). They thus provide accessible laboratories in the nearby universe for understanding star formation, supernova feedback, particle acceleration, and magnetic field amplification in early galaxies. We report the first direct radio detection of Green Peas with low frequency Giant Metrewave Radio Telescope observations and our stacking detection with archival Very Large Array FIRST data. We show that the radio emission implies that these extremely young galaxies already have magnetic fields (≳ 30 μG) even larger than that of the Milky Way. This is at odds with the present understanding of magnetic field growth based on amplification of seed fields by dynamo action over a galaxy's lifetime. Our observations strongly favor models with pregalactic magnetic fields at μG levels.
MIT Department
Massachusetts Institute of Technology. Department of Physics
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DOI of Published Version
https://doi.org/10.1088/2041-8205/746/1/l6
