3 ms·

"This is more realistic of the uncertainties involved in this high-end image reconstruction. Still amazing though! Fig. 4 in https://iopscience.iop.org/article/

• SiempreViernes 8y ago
  Yeah, apparently radio interferometry is still very manual and so involves many relatively subjective decisions to produce an image. That's probably why they had several analysers that they then combined into progressively larger teams until they could produce this Consensus-A picture.
  • petschge 8y ago
    There is non-manual ways to do it (called self-calibrating), but those need many more antennas. (What you really need is good coverage of the (u,v) plane AND many more different baselines between pairs of telescopes than the number of individual antennas.) If you do not have that self-calibration fails and leads to horrible image artifact or does not converge at all. They limited the influence of the manual calibration by observing a Quasar which is basically a point source between subsequent observations of M87* to get an independent amplitude calibration.
    • SiempreViernes 8y ago
      Some quasar other than M87 I suppose :P (It is a quasar, simbad says so and that's good enough for this setting!)
      • petschge 8y ago
        Yes. They used 3C 279 which is more than 100 times further away than M87.