English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present a study of the line-of-sight magnetic fields in fivelarge-diameter Galactic HII regions. Using the Faraday rotation of backgroundpolarized radio sources, as well as dust-corrected H-alpha surface brightnessas a probe of electron density, we estimated the strength and orientation ofthe magnetic field along 93 individual sight-lines through the HII regions.Each of the HII regions displayed a coherent magnetic field. The magnetic fieldstrength (line-of-sight component) in the regions ranges from 2 to 6microgauss, which is similar to the typical magnetic field strength in thediffuse interstellar medium. We investigated the relationship between magneticfield strength and electron density in the 5 HII regions. The slope of magneticfield vs. density in the low-density regime (0.8 < n_e < 30 per cubic cm) isvery slightly above zero. We also calculated the ratio of thermal to magneticpressure, beta_th, for each data point, which fell in the range 1.01 < beta_th< 25. Finally, we studied the orientation of the magnetic field in the solarneighborhood (d < 1.1 kpc) using our data from 5 HII regions along withexisting measurements of the line-of-sight magnetic field strength frompolarized pulsars whose distances have been determined from their annualparallax. We identify a net direction for the magnetic field in the solarneighborhood, but find no evidence for a preferred vertical direction of themagnetic field above or below the Galactic plane.

Magnetic Fields in Large Diameter HII Regions Revealed by the Faraday Rotation of Compact Extragalactic Radio Sources