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/

Zendy Plus

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

Zendy Tools

Zendy Open

We present full-polarization observations at $\lambda = 0.87$ mm (345 GHz)conducted with the Atacama Large Millimeter/submillimeter Array (ALMA) towardMessier 87 (M87) and seven other radio-loud active galactic nuclei (AGN). Wedetermine polarization and Faraday properties of the targets, with linearpolarization (LP) fractions spanning 1\% to 17\%, and Faraday rotation measures(RMs) exceeding $10^{5}$ rad m$^{-2}$. These RM values, 1-2 orders of magnitudehigher than typically observed at $\lambda > 3$ mm, suggest denser Faradayscreens or stronger magnetic fields in the (sub)millimeter emission regions.Additionally, we present the first submillimeter polarized images of the M87jet and the observed AGN. In the M87 jet, we identify RM gradients and signreversals, suggestive of a helical magnetic field structure extending overkiloparsec scales. These observations were part of the ALMA Band~7 Very LongBaseline Interferometry (VLBI) commissioning during the April 2021 EventHorizon Telescope (EHT) campaign. The results provide essential constraints forcalibrating, analyzing, and interpreting VLBI data from the EHT at 345 GHz,representing a critical step toward submillimeter VLBI imaging.

First polarization study of the M87 jet and active galactic nuclei at submillimeter wavelengths with ALMA