2000/02/21 by C. L. Brogan, D. A. Frail, W. M. Goss +1 · 4 citations
Physics and Astronomy · #Astrophysics #Astrophysics and Cosmic Phenomena #Field (mathematics) #Gamma-ray bursts and supernovae #Line (geometry) #Magnetic field #Maser #Molecular cloud #Physics #Pulsars and Gravitational Waves Research #Stars #Supernova #Thermal #Zeeman effect #astro-ph
paper · pdf · doi:10.1086/309068
23 pages, 14 figures, accepted to ApJ, for higher resolution images of Figs 4,11, and 12 see http://www.pa.uky.edu/~brogan/brog_publ.html
arxiv created 2000/02/21 · openalex publication_date 2000/07/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We have observed the OH (1720 MHz) line in five galactic SNRs with the VLA to measure their magnetic field strengths using the Zeeman effect. We detected all 12 of the bright ( S ν > 200 mJy) OH (1720 MHz) masers previously detected by Frail et al. and Green et al. and measured significant magnetic fields (i.e., >3 σ) in 10 of them. Assuming that the "thermal" Zeeman equation can be used to estimate ∣ ∣ for OH masers, our estimated fields range from 0.2 to 2 mG. These magnetic field strengths are consistent with the hypothesis that ambient molecular cloud magnetic fields are compressed via the SNR shock to the observed values. Magnetic fields of this magnitude exert a considerable influence on the properties of the cloud with the magnetic pressures (10 -7 -10 -9 ergs cm -3 ) exceeding the pressure in the ISM or even the thermal pressure of the hot gas interior to the remnant. This study brings the number of galactic SNRs with OH (1720 MHz) Zeeman detections to 10.