Peter J. Young

Young and his PhD supervisor Wallace Sargent worked with Alexander Boksenberg and made use of the Mount Palomar 200-inch Hale Telescope with Boksenberg's Image Photon Counting Spectrograph (IPCS), the first photon-counting device used in astronomy, to conduct research.^[3]

In 1978, Young et al.^[4] and Sargent et al.^[5] provided photometric and spectroscopic evidence for a supermassive black hole in the nucleus of the elliptical galaxy M87. This object was latterly revealed via direct high-resolution imaging by the Event Horizon Telescope.^[6]

In 1980, Sargent, Young, Boksenberg, and Tytler^[7] studied the Lyman-alpha forest in the rest-frame ultraviolet portion of quasar spectra, concluding that it arose from absorption by a cosmological distribution of partly ionized neutral Hydrogen. They also established the existence of the intergalactic medium. Also in 1980, Young et al. identified the galaxy responsible for the first gravitational lens, the Double Quasar Q0957+561. This paper produced the first detailed mass models for a cosmological lensing event.^[8]

In 1981, Young realized that the multiple images in Q0957+561 would be affected by the gravitational fields of a large number of stars in the lensing galaxy, leading to rapid fluctuations in the magnification of the quasar images.^[9] His theoretical study of these superimposed gravitational deflections helped initiate the subject of gravitational microlensing.^{[9][dubious – discuss]}

By the time of his death after five years at Caltech, Young had written 33 papers.^{[2][dubious – discuss]}

On 5 September 1981,^[2] Young committed suicide by taking potassium cyanide which he had obtained from a chemistry stockroom at the university.^[10] According to Sargent and Peter Goldreich, Young had suffered from depression and psychological issues since his time at Cambridge and had previously talked about killing himself.^[2][10]