VLBA17A-182

How does the M87 jet accelerate?

Abstract

The VLBI monitoring of the transversely resolved nearby radio-galaxy jet of M87 will help to answer the fundamental question on how a black hole launches a jet, and how jets are accelerated and collimated. In this proposal we like to expand the ongoing 7mm VLBI monitoring (Walker+ 2016) to a higher frequency and to better angular/spatial resolution. The latter will facilitate the motion study in the northern and southern arm of the edge-brightened jet cone and in the counter-jet.
So far no high-cadence 3mm-VLBI monitoring of M87 has been done. We therefore propose a MiniMovie Monitoring of M87 ("4M") project to study the jet kinematics and polarization on scales of 10-100 Schwarzschild radii with dense time sampling. With the higher resolution at 3mm we can trace the jet motion closer to the core and to slower speeds. Therefore we aim to fill a gap in the core-separation-velocity plot, so far not sampled. Given the too-slow time cadence of global 3mm VLBI (GMVA), we propose to use the VLBA+GBT for better time sampling. For the expected range of jet speeds we need 5 VLBI observations separated by 14+/-4 days. We also address recently discovered faint jet polarization and its possible variation.

Investigators

Name Institution
Ivan Agudo Boston University; Joint Institute for Very Long Baseline Interferometry European Research Infrastructure Consortium; Andalucía, Instituto de Astrofísica de; Andalucía, Instituto de Astrofísica de
Andrei Lobanov Max-Planck-Institut für Radioastronomie
Jose L. Gomez Andalucía, Instituto de Astrofísica de
R. Craig Walker National Radio Astronomy Observatory
Tony Zensus National Radio Astronomy Observatory; Max-Planck-Institut für Radioastronomie
zhi-qiang shen Shanghai Astronomical Observatory, CAS
Feng Yuan Shanghai Astronomical Observatory, CAS
Jae-Young Kim Max-Planck-Institut für Radioastronomie; Kyungpook National University
Thomas Krichbaum Max-Planck-Institut für Radioastronomie
Rusen Lu * Max-Planck-Institut für Radioastronomie; Shanghai Astronomical Observatory, CAS
GBT Operator Green Bank Observatory

* indicates the PI