The Cosmic X-Ray Background Nanosatellite 3 (CXBN-3): Toward an Improved Understanding of Diffuse Emission Produced by High-Redshift Active Galactic Nuclei

The Cosmic X-Ray Background Nanosatellite 3 (CXBN-3): Toward an Improved Understanding of Diffuse Emission Produced by High-Redshift Active Galactic Nuclei

Utah State University, Logan, UT

The Cosmic X-ray Background (CXB) is the diffuse emission of hard X-rays (3-300 keV) that is observed across the whole sky. The general consensus for the sources of the CXB (particularly at higher energies) are heavily obscured active galactic nuclei (AGN) located at a moderate redshift (z ≈ 1). To explore the properties of the CXB further (such as whether flux variations are present at different angular scales), the Space Science Center (SSC) at Morehead State University (MSU) is developing CXBN-3 (Cosmic X-ray Background Nanosatellite 3), a nanosatellite designed to measure the intensity of the CXB within the energy range of 20-50 keV with an uncertainty of less than 5% using a class of Cadmium Zinc Telluride detectors (with nominal energy range of 40 keV to 300 keV). The CXB peaks with an intensity of 30 keV, and by resolving this peak we can better constrain current models of the obscured AGN population and develop an accurate understanding of the temporal evolution of AGNs over a large fraction of the age of the Universe. This article will summarize the work being done by the students for the CXBN-3 mission, including science research, detector calibration and characterization, and command & data handling. This work is crucial not only in the development of CXBN-3 (as it will establish the requirements for its subsystems and instrumentation), but also for advancing these observations by improving the error in energy measurements as a function of frequency conducted at X-ray energies.