Seeking celestial Positronium with an OH-suppressed diffraction-limited spectrograph
Abstract
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.
Cite
@article{arxiv.2106.09921,
title = {Seeking celestial Positronium with an OH-suppressed diffraction-limited spectrograph},
author = {J. Gordon Robertson and Simon Ellis and Qingshan Yu and Joss Bland-Hawthorn and Christopher Betters and Martin Roth and Sergio Leon-Saval},
journal= {arXiv preprint arXiv:2106.09921},
year = {2021}
}
Comments
6 pages, 9 Figures, 2 Tables. Accepted to Applied Optics feature issue on Astrophotonics