L. M. Ziurys and B. E. Turner
HCNH+ A New Interstellar Molecular Ion,
Astrophys. J. 302, L31 L36 (1986).
The J" = 0, 1, and 2 transitions near 74.1, 148.2 and 222.3 GHz were detected in emission toward Sgr B2(OH) using the NRAO 12 m dish for the former, and the Texas MWO 4.9 m dish for the latter two transitions.
L. M. Ziurys, A. J. Apponi, and J. T. Yoder
reported on the
Detection of the Quadrupole Hyperfine Structure in HCNH+,
Astrophys. J. 397, L123 L126 (1992).
They detected the ground state transition toward the dark cloud TMC-1 using the NRAO 12 m dish.