White dwarfs with unresolved substellar companions and debris disks in the UKIDSS Survey

We present a near-infrared (NIR) photometric search for substellar companions and debris disks around white dwarfs in the UKIRT Infrared Deep Sky Survey (UKIDSS). We cross-correlate the SDSS DR4 and McCook & Sion catalogues of white dwarfs with the UKIDSS DR3 database producing 408 and 133 matches respectively. Models are then fitted to Sloan photometry to identify those with NIR photometric excesses consistent with an unresolved sub-stellar companion or a debris disk. We present follow up photometry from targets previously identified in UKIDSS DR2 and the first results from DR3. In total we identify 8 potential white dwarf + very low mass binary systems, 2 potential white dwarf + disk systems, and 2 systems which require further investigation to clarify the source of the excess.