A search for near-infrared counterparts of two faint neutron star X-ray
  transients : XMMU J174716.1-281048 and SAX J1806.5-2215
  We present our near-infrared (NIR) imaging observations of two neutron star
low mass X-ray binaries XMMU J174716.1-281048 and SAX J1806.5-2215 obtained
using the PANIC instrument on the 6.5-meter Magellan telescope and the WHIRC
instrument on the 3.5-meter WIYN telescope respectively. Both sources are
members of the class of faint to very-faint X-ray binaries and undergo very
long X-ray outburst, hence classified as `quasi persistent X-ray binaries'.
While XMMU J174716.1-281048 was active for almost 12 years between 2003 and
2015, SAX J1806.5-2215 has been active for more than 5 years now since 2011.
From our observations, we identify two NIR stars consistent with the Chandra
X-ray error circle of XMMU J174716.1-281048. The comparison of our observations
with the UKIRT Galactic plane observations taken during the same outburst,
color-color diagram analysis and spectral energy distribution suggest that both
stars are probably a part of the field population and are likely high mass
stars. Hence possibly neither of the two stars is a true NIR counterpart. For
the faint X-ray binary SAX J1806.5-2215 during its current outburst, we
detected a NIR star in our K band WIYN observations consistent with its Chandra
error circle. The identified NIR star was not detected during the UKIRT
observations taken during its quiescent state. The comparison of two
observations suggest that there was an increase in flux by at least one
magnitude of the detected star during our observations, hence suggests the
detection of the likely counterpart of SAX J1806.5-2215.
