@article{13152,
  author = {Svetlana Jorstad and Jason Dexter and et. al},
  title = {The Event Horizon Telescope Image of the Quasar NRAO 530},
  abstract = {<p>We report on the observations of the quasar NRAO 530 with the Event Horizon Telescope (EHT) on 2017 April 5−7, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A*. At z = 0.902, this is the most distant object imaged by the EHT so far. We reconstruct the first images of the source at 230 GHz, at an unprecedented angular resolution of ∼20 μas, both in total intensity and in linear polarization (LP). We do not detect source variability, allowing us to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which we associate with the core. The feature is linearly polarized, with a fractional polarization of ∼5%–8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle ∼ −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field. Future EHT observations will probe the variability of the jet structure on microarcsecond scales, while simultaneous multiwavelength monitoring will provide insight into the high-energy emission origin.</p>
},
  year = {2023},
  journal = {The Astrophysical Journal},
  volume = {943},
  number = {2},
  pages = {170},
  month = {feb},
  publisher = {The American Astronomical Society},
  url = {https://dx.doi.org/10.3847/1538-4357/acaea8},
  doi = {10.3847/1538-4357/acaea8},
}