A new study led by MPIfR (Guang-Yao Zhao) demonstrates a major advance in millimeter VLBI: the first single-optical-path frequency-phase-transfer (FPT) observations between 86 GHz and 258 GHz on an 8600 km baseline. Using APEX’s newly commissioned N3AR receiver in dual-band mode and simultaneous observations with the IRAM 30 m telescope — both supported by RadioNet — the team successfully reduced phase errors at 258 GHz by transferring phase solutions from 86 GHz. This significantly improves coherence and sensitivity at frequencies above 250 GHz.
Postprocessing of the data was performed at MPIfR in Bonn. This technique opens the door to higher-frequency, higher-fidelity VLBI imaging, enabling unprecedented precision for future studies of compact astrophysical sources. Read more in the original publication: Astronomy & Astrophysics, DOI: 10.1051/0004-6361/202555346.
Image: © MPIfR / Guang-Yao Zhao et al. – Demonstration of frequency phase transfer from 86 GHz to 258 GHz using APEX and IRAM 30 m telescopes (adapted from Fig. 1 in original publication)