FGC 1287 and its enigmatic 250 kpc long HI tail in the outskirts of
  Abell 1367
  We present HI and radio continuum, narrow-band H$\alpha$ imaging, IFU
spectroscopy, and X-ray observations of the FGC 1287 triplet projected $\sim$
1.8 Mpc west of the galaxy cluster Abell 1367. One triplet member, FGC 1287,
displays an exceptionally long, 250 kpc HI tail and an unperturbed stellar disk
which are the typical signatures of ram pressure stripping (RPS). To generate
detectable RPS signatures the presence of an Intra-cluster medium
(ICM)/intra-group medium (IGM) with sufficient density to produce RPS at a
realistic velocity relative to the ICM/IGM is a prerequisite. However,
XMM-Newton observations were not able to detect X-ray emission from the
triplet, implying that if a hot ICM/IGM is present, its density, n${_e}$, is
less than 2.6 $\times$ 10$^{-5}$ cm$^{-3}$. Higher-resolution VLA HI data
presented here show FGC 1287's HI disk is truncated and significantly warped
whereas the HI tail is clumpy. TNG H$\alpha$ imaging identified three star
forming clumps projected within 20 kpc of FGC 1287's disk, with VIMOS-IFU data
confirming two of these are counterparts to HI clumps in the tail. The
triplet's HI kinematics, together with H$\alpha$ and radio continuum imaging
suggests an interaction may have enhanced star formation in FGC 1287's disk,
but cannot readily account for the origin of the long HI tail. We consider
several scenarios which might reconcile RPS with the non-detection of ICM/IGM
X-ray emission but none of these unambiguously explains the origin of the long
HI tail.
