Seeking celestial Positronium with an OH-suppressed diffraction-limited spectrograph [IMA]

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.

Read this paper on arXiv…

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