http://arxiv.org/abs/2106.09921
Celestially, Positronium (Ps), has only been observed through gamma-ray emission produced by its annihilation. However, in its triplet state, a Ps atom has a mean lifetime long enough for electronic transitions to occur between quantum states. This produces a recombination spectrum observable in principle at near IR wavelengths, where angular resolution greatly exceeding that of the gamma-ray observations is possible. However, the background in the NIR is dominated by extremely bright atmospheric hydroxyl (OH) emission lines. In this paper we present the design of a diffraction-limited spectroscopic system using novel photonic components – a photonic lantern, OH Fiber Bragg Grating filters, and a photonic TIGER 2-dimensional pseudo-slit – to observe the Ps Balmer alpha line at 1.3122 microns for the first time.
J. Robertson, S. Ellis, Q. Yu, et. al.
Mon, 21 Jun 21
41/54
Comments: 6 pages, 9 Figures, 2 Tables. Accepted to Applied Optics feature issue on Astrophotonics