  We present XMM-Newton observations of a trail of enhanced X-rayemission
extending along the 8'.7 X 4' region between the spiral NGC6872 and the
dominant elliptical NGC6876 in the Pavo Group,the first known X-ray trail
associated with a spiral galaxy in a poor galaxy group and, with projected
length of 90 kpc, one of the longest X-ray trails observed in any system. The
X-ray surface brightness in the trail region is roughly constant beyond ~20 kpc
of NGC6876 in the direction of NGC6872. The trail is hotter (~ 1 keV) than the
undisturbed Pavo IGM (~0.5 keV) and has low metal abundances (0.2 Zsolar). The
0.5-2 keV luminosity of the trail, measured using a 67 X 90 kpc rectangular
region, is 6.6 X 10^{40} erg/s. We compare the properties of gas in the trail
to the spectral properties of gas in the spiral NGC6872 and in the elliptical
NGC6876 to constrain its origin. We suggest that the X-ray trail is either IGM
gas gravitationally focused into a Bondi-Hoyle wake, a thermal mixture of ~64%
Pavo IGM gas with ~36% galaxy gas that has been removed from the spiral NGC6872
by turbulent viscous stripping, or both, due to the spiral's supersonic motion
at angle xi ~ 40 degrees with respect to the plane of the sky, past the Pavo
group center (NGC6876) through the densest region of the Pavo IGM. Assuming xi
= 40 degrees and a filling factor eta in a cylindrical volume with radius 33
kpc and projected length 90 kpc, the mean electron density and total hot gas
mass in the trail is 9.5 X 10^{-4}*eta^{-1/2} cm^{-3} and 1.1 X
10^{10}*eta^{1/2} Msolar, respectively.
