  Parity-odd non-Gaussianities create a variety of temperature bispectra in the
cosmic microwave background (CMB), defined in the domain: $\ell_1 + \ell_2 +
\ell_3 = {\rm odd}$. These models are yet unconstrained in the literature, that
so far focused exclusively on the more common parity-even scenarios. In this
work, we provide the first experimental constraints on parity-odd bispectrum
signals in WMAP 9-year temperature data, using a separable modal parity-odd
estimator. Comparing theoretical bispectrum templates to the observed
bispectrum, we place constraints on the so-called nonlineality parameters of
parity-odd tensor non-Gaussianities predicted by several Early Universe models.
Our technique also generates a model-independent, smoothed reconstruction of
the bispectrum of the data for parity-odd configurations.
