It was difﬁcult to convince the astronomical community that X-ray telescopes had a major role to play in extrasolar X-ray research. Experimental groups at NRL and NASA Goddard Space Flight Center (GSFC) set their aims on larger and larger area detectors like those used on Uhuru, an approach that has diminishing returns. The sensitivity for non-imaging detectors only improves with the square root of the area of the detector. This is because our knowledge of the background noise improves only with the square root of the measured flux. On the other hand, the sensitivity of imaging telescopes increases linearly and yields better signal-limited detections. In other words, to achieve the sensitivity of the 1.2 meter Chandra X-Ray Observatory, an Uhuru-type detector would have had to have a surface area of one square mile! Ultimately I was able to persuade my colleagues to include an X-ray telescope in the planned series of High-Energy Astronomy Observatory (HEAO) missions.
During these years I tried to understand where the ﬁeld of X-ray astronomy was going and what would be the best institutional setting for carrying it out. My own Space Research Division at AS&E had grown to 500 people and I had become Executive Vice-President. The company began developing commercial products (like the airport X-ray scanners) rather than carrying out basic research. It seemed to me that an academic institution would provide a more appropriate setting for X-ray astronomy than a private corporation. I also thought that X-ray astronomy observations should be integrated with the rest of astronomy, and that this would be much easier if we were surrounded by optical, infrared, and radio astronomers and have the benefit of discussions with them. The need to make X-ray astronomy relevant to all disciplines in astronomy was clear if we were to have broad community support.
Multiwavelength Crab Nebula: The Crab Nebula, some 6,000 light years from Earth, is the remnant of a supernova explosion. It was seen on Earth in the year 1054. At the center of the bright nebula is a rapidly spinning neutron star, or pulsar, that emits pulses of radiation 30 times a second. This view from both space-based and ground-based telescopes shows the Crab in the X-ray, optical, infrared and radio wavelengths.
Credit: NASA/CXC/SAO (X-ray), Paul Scowen and Jeff Hester (Arizona State University) and the Mt. Palomar Observatories (optical), 2MASS/UMass/IPAC- Caltech/NASA/NSF (infrared), and NRAO/AUI/NSF (radio)