Missing Gamma-Rays from kpc-scale AGN Jets: A Test of the IC/CMB Model

Thumbnail Image

Files

1502.07942.pdf (515.63 KB)

Links to Files

https://arxiv.org/abs/1502.07942

Permanent Link

http://hdl.handle.net/11603/19507

Collections

UMBC Physics Department
UMBC Faculty Collection
UMBC Joint Center for Earth Systems Technology (JCET)

Author/Creator

Author/Creator ORCID

Date

2015-02-27

Type of Work

conference papers and proceedings preprints
Text

Department

Program

Citation of Original Publication

Eileen T. Meyer, Markos Georganopoulos, William B. Sparks, Leith Godfrey and Eric Perlman, Missing Gamma-Rays from kpc-scale AGN Jets: A Test of the IC/CMB Model, https://arxiv.org/abs/1502.07942

Rights

This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.

Subjects

Abstract

The physical origin of the X-ray emission in powerful quasar jets has been a long-standing mystery. Though these jets start out on the sub-pc scale as highly relativistic flows, we do not have any direct measurement of their speeds on the kpc scale, where the vast distances from the core necessitate in situ particle acceleration. If the jets remain highly relativistic on kpc scales, then the X-rays could be due to inverse-Compton upscattering of CMB photons. However, the IC/CMB explanation predicts a high level of gamma-ray emission, which should be detectible by the Fermi/LAT. We have searched for and ruled out this emission at a high level of significance for the well-known sources 3C 273 and PKS 0637-752, suggesting the X-rays are synchrotron, though of unknown origin. These recent results with Fermi also suggest that the kpc-scale jets in powerful quasars are significantly slower than have been presumed under the IC/CMB model. I will discuss the surprising implications of these findings for the energetics and radiative output of powerful quasars as well as their impact on their environment.