TY - JOUR
T1 - Seeking celestial positronium with an OH-suppressed diffraction-limited spectrograph
AU - Robertson, Gordon
AU - Ellis, Simon
AU - Yu, Qingshan
AU - Bland-Hawthorn, Joss
AU - Betters, Christopher
AU - Roth, Martin
AU - Leon-Saval, Sergio
PY - 2021/7/1
Y1 - 2021/7/1
N2 - Celestially, positronium (Ps) has been observed only 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 near IR 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 2D pseudo-slit—to observe the Ps Balmer alpha line at 1.3122 µm for the first time, to our knowledge.
AB - Celestially, positronium (Ps) has been observed only 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 near IR 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 2D pseudo-slit—to observe the Ps Balmer alpha line at 1.3122 µm for the first time, to our knowledge.
UR - http://www.scopus.com/inward/record.url?scp=85108572575&partnerID=8YFLogxK
U2 - 10.1364/AO.421560
DO - 10.1364/AO.421560
M3 - Article
C2 - 34263851
AN - SCOPUS:85108572575
SN - 1559-128X
VL - 60
SP - D122-D128
JO - Applied Optics
JF - Applied Optics
IS - 19
ER -