GMVA21B-281

Probing Relativistic Jets through mm-VLBI of X-ray Binaries

Abstract

One of the key open questions in high energy astrophysics is understanding how black holes act as powerful cosmic engines, gravitationally capturing material and expelling matter in the form of relativistic jets. Stellar-mass black holes in Galactic X-ray binaries are ideal test-beds for jet phenomena, as they vary over rapid timescales, providing a real-time view of how the accretion-jet coupling in black holes evolves and how the jets interact with their environment. Radio-VLBI has successfully resolved these jets down to milli-arcsec scales (corresponding to physical scales of ~10^8 Rg at kpc distances). However, the mm/sub-mm wavebands, which can probe emission much closer to the black hole (~10^6 Rg; zeroing in on the jet launching region), have yet to be thoroughly explored. We propose for a total of 22 hrs of GMVA observations to obtain high angular resolution imaging of three bright (~hundreds of mJy) X-ray binary jet sources. With these data, we will measure jet morphology, size-scales, speed, geometry, and energetics. These pioneering GMVA observations will also pave the way towards a coordinated multi-wavelength campaign with the Event Horizon Telescope array observing at 1 mm wavelengths.

Investigators

Name	Institution
Sera Markoff	Amsterdam, Universiteit van
Eduardo Ros	Max-Planck-Institut für Radioastronomie; València, Universitat de
Thomas Krichbaum	Max-Planck-Institut für Radioastronomie
Maciek Wielgus	Max-Planck-Institut für Radioastronomie; Smithsonian Astrophysical Observatory
Venkatessh Ramakrishnan	Turku, University of
Geoffrey Bower	Academia Sinica
Alexandra Tetarenko *	Alberta, University of; Texas Tech University; East Asian Observatory; Lethbridge, University of
GBT Operator	Green Bank Observatory

* indicates the PI