A Search for l-C3H+ and l-C3H in Sgr B2(N), Sgr B2(OH), and the Dark
  Cloud TMC-1
  Pety et al. (2012) recently reported the detection of several transitions of
an unknown carrier in the Horsehead PDR and attribute them to l-C3H+. Here, we
have tested the predictive power of their fit by searching for, and
identifying, the previously unobserved J=1-0 and J=2-1 transitions of the
unknown carrier (B11244) towards Sgr B2(N) in data from the publicly available
PRIMOS project. Also presented here are observations of the J=6-5 and J=7-6
transitions towards Sgr B2(N) and Sgr B2(OH) using the Barry E. Turner Legacy
Survey and results from the Kaifu et al. (2004) survey of TMC-1. We calculate
an excitation temperature and column density of B11244 of ~10 K and ~10^13 cm-2
in Sgr B2(N) and ~79 K with an upper limit of < 1.5 x 10^13 cm-2 in Sgr B2(OH)
and find trace evidence for the cation's presence in TMC-1. Finally, we present
spectra of the neutral species in both Sgr B2(N) and TMC-1, and comment on the
robustness of the assignment of the detected signals to l-C3H+.
