VLBI Imaging of M81* at λ = 3.4 mm with Source-frequency Phase-referencing
VLBI Imaging of M81* at λ = 3.4 mm with Source-frequency Phase-referencing
Abstract We report on the first VLBI image of the M81 nucleus (M81*) at a wavelength of 3.4 mm, obtained with the source-frequency phase-referencing (SFPR) technique. Thanks to the SFPR calibration, the coherent integration time eventually could be increased by more than an order of magnitude, which enabled the detection …