X-ray Emission from the Taffy (VV254) Galaxies and Bridge
  We present the first X-ray observations of the Taffy galaxies (UGC 12914/5)
with the Chandra observatory, and detect soft X-ray emission in the region of
the gas-rich, radio-continuum-emitting Taffy bridge. The results are compared
to Herschel observations of dust and diffuse [CII] line-emitting gas. The
diffuse component of the Taffy bridge has an X-ray luminosity of L(X)
(0.5-8keV) =5.4 x 10^39 erg s^-1, which accounts for 19% of the luminosity of
the sum for the two galaxies. The total mass in hot gas is (0.8--1.3) x 10^8
M_sun, which is approximately 1% of the total (HI~+~H2) gas mass in the bridge,
and ~11% of the mass of warm molecular hydrogen discovered by Spitzer. The soft
X-ray and dense CO-emitting gas in the bridge have offset distributions, with
the X-rays peaking along the north-western side of the bridge in the region
where stronger far-IR dust and diffuse [CII] gas is observed by Herschel. We
detect nine Ultra Luminous X-ray sources (ULXs) in the system, the brightest of
which is found in the bridge, associated with an extragalactic HII region. We
suggest that the X-ray--emitting gas has been shocked--heated to high
temperatures and "splashed" into the bridge by the collision. The large amount
of gas stripped from the galaxies into the bridge and its very long gas
depletion timescale (>10 Gyr) may explain why this system, unlike most major
mergers, is not a powerful IR emitter.
