  For accurate modelling of observations of exoplanet atmospheres,
quantification of the pressure broadening of infrared absorption lines for and
by a variety of gases at elevated temperatures is needed. High-resolution
high-temperature H2-pressure-broadened spectra are recorded for the CH4 v3-band
P-branch. Measured linewidths for 116 transitions between 2840 and 3000 cm^{-1}
with temperature and pressures ranging between 300 and 700 K, and 10 and 933
Torr, respectively, were used to find rotation- and
tetrahedral-symmetry-dependent coefficients for pressure and temperature
broadening and pressure-induced lineshifts. The new pressure-broadening data
will be useful in radiative-transfer models for retrieving the properties of
observed expolanet atmospheres.
