[C ii] 158 μm line detection of the warm ionized medium in the Scutum-Crux spiral arm tangency T. Velusamy, W. D. Langer, J. L. Pineda and P. F. Goldsmith A&A, 541 (2012) L10 Published online: 17 May 2012 DOI: 10.1051/0004-6361/201219303