We present spectral and spatial information for major volatile species in
Comet 10P/Tempel 2, based on high-dispersion infrared spectra acquired on UT
2010 July 26 (heliocentric distance Rh = 1.44 AU) and September 18 (Rh = 1.62
AU), following the comet's perihelion passage on UT 2010 July 04. The total
production rate for water on July 26 was (1.90 +/- 0.12) x 10^28 molecules s-1,
and abundances of six trace gases (relative to water) were: CH3OH (1.58% +/-
0.23), C2H6 (0.39% +/- 0.04), NH3 (0.83% +/- 0.20), and HCN (0.13% +/- 0.02). A
detailed analysis of intensities for water emission lines provided a rotational
temperature of 35 +/- 3 K. The mean OPR is consistent with nuclear spin
populations in statistical equilibrium (OPR = 3.01 +/- 0.18), and the (1-sigma)
lower bound corresponds to a spin temperature > 38 K. Our measurements were
contemporaneous with a jet-like feature observed at optical wavelengths. The
spatial profiles of four primary volatiles display strong enhancements in the
jet direction, which favors release from a localized vent on the nucleus. The
measured IR continuum is much more sharply peaked and is consistent with a
dominant contribution from the nucleus itself. The peak intensities for H2O,
CH3OH, and C2H6 are offset by ~200 km in the jet direction, suggesting the
possible existence of a distributed source, such as the release of icy grains
that subsequently sublimed in the coma. On UT September 18, no obvious emission
lines were present in our spectra, nevertheless we obtained a 3-sigma upper
limit Q(H2O) < 2.86 x 10^27 molecules s-1
