We have combined high resolution VLBI Space Observatory Programme (VSOP) data at 1.6 and 4.8 GHz with Very Long Baseline Array (VLBA) data at higher frequencies and with similar resolutions to study the spectral properties of the core of M87 with milliarcsecond resolution. The VSOP data allow a more accurate measurement of the turn-over frequency, and hence more reliable determination of associated physical parameters of the source. Comparison of the images with previously published images yields no evidence for significant motion of components in the parsec-scale jet. In addition, the brightness temperatures obtained from model-fits to the core are well below the inverse Compton limit, suggesting the radio emission we are observing is not strongly Doppler boosted. Colour version on http://www.vsop.isas.jaxa.jp/survey/publications/m87.ps.gz
@article{arxiv.astro-ph/0511383,
title = {Milli-arcsecond--scale Spectral Properties and Jet Motions in M87},
author = {Richard Dodson and Philip G. Edwards and Hisashi Hirabayashi},
journal= {arXiv preprint arXiv:astro-ph/0511383},
year = {2015}
}
Comments
To appear in PASJ VSOP special issue. Minor corrections