GBT16B-199

Evolution of High Brightness Temperature AGN Cores with RadioAstron

Abstract

The RadioAstron AGN survey has detected about 150 targets on SVLBI baselines, with estimated brightness
temperatures of their cores lying typically in the range of 10^12 to 10^14 K. This has important implications for the emission mechanisms and kinematics of relativistic outflows from supermassive black holes.
The new proposed project builds on the success of the survey and involves monitoring the brightest and most compact targets selected from the survey results in order to study the properties and physics of their variable emission.
This strategy also maximizes our chance to detect brightness temperatures in excess of 10^14 K, should they exist.
We request 158 hours of the GBT time for the period July 2016 - June 2017 inclusive to observe the 27 of the brightest AGNs, and up to 8 flaring AGNs with RadioAstron and GBT at L/C/K bands.
As the most sensitive available ground telescope, GBT is crucial to the project to provide the required sensitivity to measure high brightness temperatures, given the small size of the space radio telescope and the low correlated flux densities.
These observations will attain the highest resolution available from direct astronomical observations.

Investigators

Name	Institution
Yuri Kovalev *	Max-Planck-Institut für Radioastronomie
GBT Operator	Green Bank Observatory
Leonid Gurvits	Joint Institute for Very Long Baseline Interferometry European Research Infrastructure Consortium
Petr Voytsik	Lebedev Physical Institute
Tony Zensus	National Radio Astronomy Observatory; Max-Planck-Institut für Radioastronomie
Nikolai Kardashev	Lebedev Physical Institute
Michael Bietenholz	York University; Hartebeesthoek Radio Astronomy Observatory
Kirill Sokolovsky	Illinois at Urbana-Champaign, University of
James Anderson	Deutsches GeoForschungsZentrum

* indicates the PI