Two distant brown dwarfs in the UKIRT Infrared Deep Sky Survey Deep
  Extragalactic Survey Data Release 2
  We present the discovery of two brown dwarfs in the UKIRT Infrared Deep Sky
Survey (UKIDSS) Deep Extragalactic Survey (DXS) Data Release 2. Both objects
were selected photometrically from six square degrees in DXS for their blue J-K
colour and the lack of optical counterparts in the Sloan Digital Sky Survey
(SDSS) Stripe 82. Additional optical photometry provided by the
Canada-France-Hawaii Telescope Legacy Survey (CFHT-LS) corroborated the
possible substellarity of these candidates. Subsequent methane imaging of UDXS
J221611.51+003308.1 and UDXS J221903.10+002418.2, has confirmed them as
T7$\pm$1 and T6$\pm$1 dwarfs at photometric distances of 81 (52-118 pc) and 60
(44-87 pc; 2 sigma confidence level). A similar search in the second data
release of the Ultra Deep Survey over a smaller area (0.77 square degree) and
shallower depth didn't return any late-T dwarf candidate. The numbers of late-T
dwarfs in our study are broadly in line with a declining mass function when
considering the current area and depth of the DXS and UDS. These brown dwarfs
are the first discovered in the VIMOS 4 field and among the few T dwarfs found
in pencil-beam surveys. They are valuable to investigate the scale height of T
dwarfs.
