VLBA21A-014

Unveiling particle acceleration regions in the X-ray emitting hotspot 3C227 West

Abstract

We propose high sensitivity array (HSA) observations at 5 GHz of the X-ray emitting hotspot 3C227 West. The discovery of diffuse optical and X-ray
emission in this hotspot requires a revision of the standard scenario of
particles accelerated by a single strong shock generated at the jet termination. In a scenario in which X-ray emission is synchrotron radiation,
high energy electrons should arise from very small regions because their short lifetime would limit their emission at a narrow emitting disk. Extended emission may be interpreted in terms of either multiple, transient shock structures likely produced by jet dithering, or turbulence. Our Very Large Array (VLA) observations of this hotspot point out the presence of unresolved regions and set an upper limit to their size of about 75 mas (100 pc). However, the expected size of transient features should be of the order of a few parsecs, i.e. much smaller than the size proved by the JVLA observations. The proposed HSA observations will allow us to constrain the size of these transient regions, improving our knowledge of jet interaction processes at the edge of powerful radio galaxies.

Investigators

Name	Institution
Karl-Heinz Mack	Istituto Nazionale di Astrofisica
Filippo D'Ammando	Istituto Nazionale di Astrofisica
Gianfranco Brunetti	Istituto Nazionale di Astrofisica
Giulia Migliori	Istituto Nazionale di Astrofisica
Monica Orienti *	Istituto Nazionale di Astrofisica; Bologna, Università degli Studi di
GBT Operator	Green Bank Observatory

* indicates the PI