As it has done most years, the NuSTAR group in Pasadena has hosted a number of undergraduate researchers through the Caltech SURF and WAVE programs. They come from institutions around the country, including Caltech, UC Los Angeles, UC San Diego, Pennsylvania State, Harvard, and more, and are working on a range of projects, including characterizing Galactic black holes and neutron stars, studying the variation of supermassive black holes in X-rays and infrared, and simulation development for X-ray telescopes and the upcoming UVEX mission. In addition to their research projects, most of the students participated in a night of observing with the 200-inch Hale Telescope at Palomar Observatory in July, getting the full experience of ground-based observing. Also, last Friday, a number of the students, as well as some local high school students who are gaining laboratory work experience with the UVEX team, participated in a tour of the Jet Propulsion Laboratory led by Drs. Varoujan Gorjian and Alina Kiessling, where they learned about the history of the lab, the deep space network and mission operations at JPL, and saw the NASA ASTHROS balloon mission in the highbay.

Also during the past week, NuSTAR observed WISEA J025655.94−152105.8 in coordination with ESA’s XMM-Newton observatory. The target is a distant active galactic nucleus (AGN) powered by an accreting supermassive black hole (SMBH) at the center of its host galaxy. These observations are part of the approved NuSTAR Large Program PACHA (Probing AGN Coronae with High-redshift AGN), which has been awarded more than 500 ks of NuSTAR and 120 ks of XMM-Newton observing time. AGN coronae are responsible for producing more than 90% of the X-ray emission in the extragalactic Universe. However, despite their fundamental importance, the physical nature of these coronae remains poorly understood. The coordinated NuSTAR and XMM-Newton observations will enable precise measurements of the coronal properties of distant AGN and provide decisive tests of current theoretical models of AGN coronae. The results will also offer important insights into the accretion physics of SMBHs and improve our understanding of how these extreme systems generate their powerful X-ray emission. For a related study of a similar source by the same observing group, see https://nustar.caltech.edu/news/nustar260602

Authors: Hannah Earnshaw (NuSTAR Project Scientist, Caltech) and Xiurui Zhao (Postdoctoral Scholar, Caltech)