The energy that galaxies release over their lifetimes comes from two sources: the emission from stars and the accretion of gas and dust onto supermassive black holes now understood to be at the center of most galaxies (Active Galactic Nuclei, AGN). However, the present inventory of accretion power in the Universe indicates that up to 50% of this emission is invisible to most surveys, hidden by highly obscured material. Surveys of AGN measuring extended low-frequency radio emission from relativistic jets of plasma provide a measure of the intrinsic accretion powered luminosity, and have been used to identify a sample of high redshift AGN that should be unbiased toward obscuration. NuSTAR observations of three of such high redshift AGN, selected as part of the cycle-11 General Observer program, have been performed over the last few months. The targets were chosen because previous observations by NASA’s Chandra X-ray observatory were unable to distinguish whether the measured faint low-energy X-ray flux was due to viewing the AGN through dense obscuring material or if the AGN are intrinsically low luminosity. NuSTAR measurements of the high-energy X-ray flux from these AGN will be able to distinguish between these two possibilities and determine if these powerful radio galaxies conform with a ‘unified’ model of the structure of all AGN, or if a new model for emission from high redshift radio galaxies is needed.
 
Two weeks ago, NuSTAR Project Scientist Hannah Earnshaw attended the first Observatories Forum conference in Santa Barbara, convened by the AEON+ collaboration of astronomical telescopes. The topic of the forum was to discuss from a development perspective the challenges and strategies for more efficient telescope operations, particularly in an era of increased time-domain science needs. Hannah presented an overview of NuSTAR mission operations and the particular constraints that arise for space-based missions, as well as an update on NuSTAR's new rapid target-of-opportunity response system. There was also an update from ACROSS, an upcoming NASA facility to enable better coordination of time-domain response from NASA's astrophysics missions, which the NuSTAR team has been assisting since early on the development process and plans to be involved as the system goes live in the next couple of months. 

Authors: Joanna Kuraszkiewicz (Astronomer, Smithsonian Astrophysical Observatory), Hannah Earnshaw (NuSTAR Project Scientist, California Institute of Technology)